the clinical and non-clinical aspects of distal radioulnar joint

THE CLINICAL AND NON-CLINICAL

ASPECTS OF DISTAL RADIOULNAR JOINT INSTABILITY AFTER A DISTAL RADIUS FRACTURE

Mathieu M.E. Wijffels

THE CLINICAL AND NON-CLINICAL ASPECTS

OF DISTAL RADIOULNAR JOINT INSTABILITY

AFTER A DISTAL RADIUS FRACTURE

Mathieu M.E. Wijffels

This thesis was prepared at the Department of Trauma Surgery, Leiden University Medical Center & Leiden University, Leiden, the Netherlands and the Orthopaedic Hand and Upper Extremity Unit, Massachusetts General Hospital & Harvard Medical School, Boston, MA, United States of America

Author: Mathieu M.E. WijffelsCover photo: Mathieu M.E. WijffelsPrinted by: Optima Grafische Communicatie, Rotterdam, The Netherlands

I would gratefully acknowledge the research support I received from the Bontius Stich-ting.

All rights reserved. No parts of this thesis may be reproduced, distributed, stored in a retrieval system or transmitted in any form or by any means, without permission of the author, or when appropriate, of the publisher of the publications.

ISBN: 978-94-6169-652-6

This thesis has been sponsored by: Nederlandse Vereniging voor Traumachirurgie, Push Braces (Push.eu), Traumacentrum West, Universiteit Leiden, Anna Fonds|NOREF, Covidien, Pro-Motion Medical, Fysiotherapie Leuvehaven, Oldekamp Medisch, Livit Orthopedie B.V., Simendo B.V., Imagehub (Aexist.nl)

THE CLINICAL AND NON-CLINICAL ASPECTS

OF DISTAL RADIOULNAR JOINT INSTABILITY

AFTER A DISTAL RADIUS FRACTURE

Proefschrift

ter verkrijging vande graad van Doctor aan de Universiteit Leiden,

op gezag van Rector Magnificus prof. mr. C.J.J.M. Stolker,volgens besluit van het College voor Promoties

te verdedigen op donderdag 1 oktober 2015 klokke 16.15 uur.

door

Mathieu Mathilde Eugene Wijffelsgeboren te Waterlandkerkje in 1980

PROmOTIECOmmISSIE

Promotor: Prof. Dr. I.B. Schipper

Overige Leden: Prof. Dr. R.S. Breederveld, Leiden University Medical Center, Leiden Prof. Dr. J.L. Bloem, Leiden University Medical Center, Leiden Prof. Dr. J.C. Goslings, Academic Medical Center, Amsterdam

Aan Stéphanie en Emma.

LIST OF ABBREvIATIONS

AP anterioposteriorCI confidence intervalCT computed tomographyDASH disabilities of the arm, shoulder and handDRF distal radius fractureDRU distal radioulnarDRUJ distal radioulnar jointECU extensor carpi ulnarisFCR flexor carpi radialisGRADE grading of recommendation assessment, development and evaluationICC intraclass correlation coefficientsIM interosseous membraneMPQ musculus pronator quadratusMR magnetic resonanceMRI magnetic resonance imagingPRISMA preferred reporting items for systematic reviews and meta-analysisPRWE patient-rated wrist evaluation scoreSD standard deviationSLE systemic lupus erythematosusSK Sauve-KapandjiTFCC triangular fibrocartilage complexUSF ulnar styloid fractureUSP ulnar styloid process2DCT two-dimensional computed tomography

CONTENTS

Part I Clinical and non-clinical aspects of distal radioulnar joint instability after a distal radius fracture

11

Chapter 1 Introduction and outline of this thesis 13

Chapter 2 Clinical and non-clinical aspects of distal radioulnar joint instability 25

Part II Radiological Aspects 41

Chapter 3 Interobserver variation in the diagnosis of coronal articular fracture lines in the lunate facet of the distal radius

43

Chapter 4 Computed tomography for the detection of distal radioulnar joint instability: Normal variation and analysis of four CT scoring systems in 46 patients

53

Part III Acute treatment 65

Chapter 5 Impact of ulnar styloid fractures in non-operatively treated distal radius fractures

67

Chapter 6 The influence of non-union of the ulnar styloid on pain, wrist function and instability after distal radius fracture

81

Chapter 7 Ulnar styloid process non-union and outcome in patients with a distal radius fracture: a meta-analysis of comparative trials

91

Chapter 8 Clinical DRUJ instability does not influence the long term functional outcome of conservatively treated distal radius fractures

109

Part Iv Delayed treatment 121

Chapter 9 The extended flexor carpi radialis approach for partially healed mal-aligned fractures of the distal radius

123

Chapter 10 The Darrach procedure for post-traumatic reconstruction 135

Part v General discussion and summary 147

Chapter 11 General discussion and future perspectives 149

Chapter 12 Summary 161

Chapter 13 Appendices 169

Summary in Dutch (Nederlandse samenvatting) 171

List of publications 176

Acknowledgements (Dankwoord) 181

Curriculum Vitae 183

12345678910111213

Part IClinical and non-clinical aspects of distal

radioulnar joint instability after a distal radius fracture

12345678910111213

Chapter 1Introduction and outline of this thesis

M.M.E. Wijffels, P. Krijnen, I.B. Schipper

15

Introduction and outline of this thesis

1GENERAL INTRODUCTION AND OUTLINE OF THE THESIS

Distal radius fractures are common; one of every six patients treated for a fracture at emergency departments is suffering from a distal radius fracture.1-3 A potential compli-cating factor, with a negative influence on the outcome of distal radius fracture treat-ment, is distal radioulnar joint (DRUJ) instability, which often remains unnoticed at the time of injury. The reported incidence of DRUJ instability one year after a distal radius fracture varies from 0-35%.4-6

ANATOmY

The DRUJ is formed by the distal sides of the radius, the sigmoid notch and distal ulna, the ulnar seat. When extensive translations in curvatures of the articulating surfaces arise, the DRUJ may become unstable. Therefore stabilizing structures are needed to provide stabilization of the joint in pronosupination and during transmission of forces from hand to forearm.7 These stabilizing structures can be subdivided based on anatomical location. Extracapsular stabilizers are the tendon of the musculus extensor carpi ulnaris, the sixth dorsal compartment, the musculus pronator quadratus and the interosseous membrane.8-10 The intracapsular stabilizer, also assumed to be the most

Figure 1.1. intracapsular stabilizers of the DRUJ

Chapter 1

16

important stabilizer, is the triangular fibrocartilage complex (TFCC). Figure 1.1. The radioulnar ligaments, as part of the TFCC, originate from the medial border of the distal radius and insert on the ulna at two distinct sites; deep fibers at the ulnar fovea and superficial fibers at the ulnar styloid. Figure 1.2.

ACUTE TREATmENT

44-65% of distal radius fractures are accompanied by an ulnar styloid fracture (USF).11-14 DRUJ instability may result from an USF fracture, due to the disrupted TFCC insertion.15-20 Theoretically, increased fracture instability, due to ligamentous disruption, may result in secondary fracture displacement after closed reduction. As a consequence the presence of USF may indicate distal radius fracture instability, but so far no study has focused on the influence of an USF in the acute setting.

The optimal management of a fracture at the base of the ulnar styloid associated with a distal radius fracture is open to debate. Should a fractured ulnar styloid be fix-ated?4,5,13,16,19,21-24 Most of the studies on this topic are heterogeneous in treatment modality and fracture types, and level 1 evidence is lacking. Many ulnar styloid fractures result in non-unions. Analogue to the theory of TFCC disruption in acute ulnar styloid fractures, USF non-unions may cause DRUJ instability and, consequently, compromise results after distal radius fracture consolidation. The long-standing concern about ulnar styloid base fractures12,13,16,22,24-28 has been questioned by four recent studies; they found such fractures do not affect the outcome of distal radius fractures treated with volar plate fixation.23,29,30,31 To correct for heterogeneous data a meta-analysis is presented in this thesis focusing on the influence of ulnar styloid non-union on the outcome of distal radius fractures. Most patients included in the studies focusing on ulnar styloid

Figure 1.2. superficial and deep radioulnar fibers of the TFCC.

17


1fractures and non-union, analyzed operatively treated distal radius fractures. Data on the influence of an ulnar styloid base fracture on the outcome of conservatively treated distal radius fractures is lacking. Information on comparison of stability of a distal radius after closed reduction with and without an USF would help to gain further insight into the biomechanical role of the ulnar styloid as part of the DRUJ stabilizers.

The incidence of DRUJ instability after distal radius fractures varies widely between studies.4-6 In most of these studies the presence of DRUJ instability was evaluated after various treatment modalities within one study, resulting in heterogeneous groups. Although there is a recent tendency towards more surgical treatment, the majority of distal radius fractures is still treated conservatively.32-35 Compared to operatively treated distal radius fractures, less is known about the influence of DRUJ instability on conserva-tively treated distal radius fractures.

RADIOLOGICAL ASPECTS

Diagnosing DRUJ instability is a challenge. Clinical tests suffer from subjectivity and lack of validity.36 Radiographs do not depict the dynamic process of DRUJ instability and true lateral views are hard to obtain.4,37-40 Computed tomography (CT) can overcome these shortcomings and it has been suggested that it be used to aid in the identification of DRUJ injuries accompanying distal radius fractures.41-43 Several methods for determining DRUJ translation by means of a wrist-CT have been proposed,37,40,44-46 but only one paper focused on the reliability of these methods.47 The value of CT-scans in diagnosing DRUJ involvement in distal radius fractures and determination of DRUJ laxity was there for studied in this thesis, focusing on multi-observer agreement.

DELAYED TREATmENT

Probably because of the various non-specific and unvalidated radiographic indicators for DRUJ instability, DRUJ instability is frequently detected after distal radius fracture consolidation.38,48,49 In the acute setting no further diagnostic help can be expected from clinical tests. Furthermore, it is unpredictable which unstable DRUJ will cause future complaints needing treatment. Therefore, after diagnosing DRUJ instability and when operative treatment is considered, patients’ symptoms must be evaluated thoroughly. Pain occurs in about 2/3 of the DRUJ unstable patients.5 Alternatively, DRUJ instability may cause invalidating pain or loss of function. If symptomatic DRUJ instability is diag-nosed, conservative treatment can only be successful in the presence of a congruent DRUJ. Therefore, the first step in the treatment of painful DRUJ instability after a mal-

Chapter 1

18

united distal radius fracture, is the correction of the osseous anatomy. Partial healing or fracture consolidation in the malaligned position and contracture of the soft tissue around the distal radius renders open reduction and internal fixation more difficult. The application of a temporary distractor to enable definitive fixation can be useful, but at the price of comorbidity such as more scars and tendon-, vascular- or nerve injury. A volar plate can be used as a reduction device by fixing it to the distal fracture fragment first, but shortened soft tissues may prevent radial length restoration. As an alternative, a surgical technique to release the mal-united distal radius and enable open reduction and internal fixation, referred to as the “extended flexor carpi radialis (FCR) exposure” was described.50 Although promising, the safety and utility of the extended FCR expo-sure followed by volar locking plate fixation has never been evaluated.

In the absence of osseous malalignment the next step in the treatment of DRUJ instability is anatomic or non-anatomic reconstruction of DRUJ-stabilizing structures. Tendons may be used to increase stability but the outcome is often disappointing.51-55 If ongoing wrist pain or loss of function remains present after stability reconstructive surgery, various salvage techniques have been described. Alternatives for the DRUJ reconstruction include the Sauve-Kapandji procedure,56 partial resection of the distal ulna as described by Watson57, or Bowers,58 an ulna diaphyseal shortening osteotomy,59 a distal ulna wafer resection,60 or resection of the distal ulna.61 This so called Darrach pro-cedure is favored for its simplicity, as compared to other salvage procedures, to address complex post-traumatic DRUJ dysfunction. As a result of publications that reported fail-ure of pain relief and poor outcome, this procedure is used less frequently.62-68 Overall, the outcome of salvage procedure in post-traumatic wrist problems is still subject of many studies. Despite all efforts to optimally restore the joint after a fracture, there will always be patients that remain to be treated with one of the various salvage procedures described above.

19


1OUTLINE OF THE THESIS

The overall objective of this thesis was to evaluate the influence of posttraumatic distal radioulnar joint changes on the outcome of distal radius fractures and the role of CT-scans in diagnosing DRUJ instability. In addition the need to address USF fixation in distal radius patients and treatment options for posttraumatic DRUJ changes are evaluated.

Part I describes the clinical and non-clinical aspects of DRUJ instability, in Chapter 2.

Part II addresses the role of CT in DRUJ injuries. In Chapter 3, the change of interobserver agreement on diagnosing a coronal split of the lunate facet by adding a CT-scan to stan-dard radiographs, is discussed. The questions to be answered in this study were:• Does the CT-scan, in addition to conventional radiographs, improve the interob-

server agreement on diagnosing coronal articular distal radius fractures compared to just the radiographs.

• Does the CT-scan, in addition to conventional radiographs, improve the interob-server agreement on the determination of fracture instability in coronal lunate facet fractures, compared to just radiographs?

• Doestheinterobserveragreementondiagnosingcoronaldistalradiusfracturesanddetermination of fracture instability depend on observer characteristics?

Chapter 4 describes the reliability of various scoring methods for DRUJ translation after consolidated, conservatively treated distal radius fractures and defines normal values for DRUJ translation based on uninjured wrists. The aim of this study was to find answers to the questions:• What is themost reliablemethod for thedeterminationofDRUJ instability using

CT-scans of the wrist?• Is there any difference in intra- and interobserver on the determination of DRUJ

instability using CT-scans comparing posttraumatic wrists with normal wrists?• WhatarethenormalvaluesformotionintheDRUJ?

Part III describes the influence of an USF and of DRUJ instability on the outcome of distal radius fractures. In Chapter 5 we evaluated the influence of ulnar styloid fractures on the stability of distal radius fractures after closed reduction and aimed to answer the question:• Is lossofdistal radius fracture reductionmore common in thepresenceof anac-

companying USF compared to distal radius fractures without an accompanying USF?Chapter 6 describes the influence of an ulnar styloid base fracture on pain, wrist func-tion and DRUJ instability after operatively treated distal radius fractures. The question to be answered in this chapter was:

Chapter 1

20

• Doesnon-unionofanulnarstyloidbasefracturecompromisetheoutcomeofopera-tively treated distal radius fractures?

Chapter 7 contains the results of a meta-analysis which addressed whether patient reported outcome, function, pain or DRUJ stability is influenced by non-union of the accompanying USF in distal radius fractures. The meta-analysis was intended to answer the question:• Isthereanydifferenceinoutcomeofdistalradiusfractureswithandwithoutpres-

ence of an ulnar styloid non-union?Chapter 8 discusses the results of a prospective study performed to assess the influence of clinical DRUJ instability on the long-term outcome of conservatively treated distal radius fractures. The question that is answered in this chapter is:• Does theclinicaldiagnosisofDRUJ instability influencetheoutcomeofconserva-

tively treated distal radius fractures after mid-term follow-up?

Part IV focusses on the delayed treatment of posttraumatic DRUJ changes. A new op-erative technique to correct malunion of a distal radius fracture, the so called extended flexor carpi radialis approach is discussed in Chapter 9. The purpose of this study was to answer the question:• Is theextendedflexorcarpi radialisapproach followedbyvolarplatingasafeand

effective procedure to correct partially healed malaligned fractures of the distal radius?

In Chapter 10, the results after a Darrach procedure are discussed in a descriptive cohort study. The main question in this chapter is:• IstheDarrachprocedureeffectiveinregainingforearmmobilityafter,amongstoth-

ers, symptomatic posttraumatic DRUJ changes?

Part V consists of 3 chapters. Chapter 11 provides the general discussion of and future perspectives on the topic of this thesis. It also enumerates the answers on stated ques-tions and clinical consequences of the studies described in this thesis. In Chapter 12 the summary of this dissertation in English is presented. Chapter 13 contains the summary in Dutch, list of publications, acknowledgements and the authors curriculum vitae.

REFERENCES

1. Hollingsworth R, Morris J. The importance of the ulnar side of the wrist in fractures of the distal end of the radius. Injury. 1976; 7(4): 263-6

2. Lindau RT, Aspenberg P, Arner M, et al. Fractures of the distal forearm in young adults. An epide-miologic description of 341 patients. Acta Orthop Scand. 1999; 70(2): 124-8

21


1 3. Sammer DM, Shah HM, Shauver MJ, et al. The effect of ulnar styloid fractures on patient-rated

outcomes after volar locking plating of distal radius fractures. J Hand Surg [Am]. 2009; 34(9): 1595-602

4. Lindau T, Adlercreutz C, Aspenberg P. Peripheral tears of the triangular fibrocartilage complex cause distal radioulnar joint instability after distal radial fractures. J Hand Surg [Am] 2000; 25(3): 464-8.

5. Lindau T, Hagberg L, Adlercreutz C, et al. Distal radioulnar instability is an independent worsening factor in distal radial fractures. Clin Orthop Relat Res. 2000; 376: 229-35

6. Krämer S, Meyer H, O’Loughlin P, et al. The incidence of ulnocarpal complaints after distal radial fracture in relation to the fracture of the ulnar styloid. J Hand Surg Eur. 2013; 38; 710-7.

7. Af Ekenstam F, Hagert CG. Anatomical studies on the geometry and stability of the distal radio ulnar joint. Scand J Plast Reconstr Surg 1985; 1: 17-25

8. Spinner M, Kaplan EB. Extensor carpi ulnaris. Its relationship to the stability of the distal radio-ulnar joint. Clin Orthop Relat Res 1970; 68: 124-9

9. Gerber A, Masquelet AC. Anatomy and intracompartmental pressure measurement technique of the pronator quadratus compartment. J Hand Surg [Am] 2001; 26(6): 1129-34

10. Poitevin LA. Anatomy and biomechanics of the interosseous membrane: its importance in the longitudinal stability of the forearm. Hand Clin 2001; 17(1): 97-110.

11. Frykman G. Fracture of the distal radius including sequelae—shoulder-hand-finger syndrome, disturbance in the distal radioulnar joint and impairment of nerve function. A clinical and experi-mental study. Acta Orthop Scand. 1967; 108(Suppl): 7–153

12. Lindau T, Arner M, Hagberg L. Intraarticular lesions in distal fractures of the radius in young adults. A descriptive arthroscopic study in 50 patients. J Hand Surg [Br]. 1997; 22(5): 638–43.

13. Oskarsson GV, Aaser P, Hjall A. Do we underestimate the predictive value of the ulnar styloid affection in Colles fractures? Arch Orthop Trauma Surg. 1997; 116(6–7): 341–4.

14. Richards RS, Bennett JD, Roth JH et al. Arthroscopic diagnosis of intra-articular soft tissue injuries associated with distal radial fractures. J Hand Surg [Am]. 1997; 22(5): 772–6.

15. Adams BD, Samani JE, Holley KA. Triangular fibrocartilage injury: a laboratory model. J Hand Surg [Am]. 1996; 21(2): 189-93

16. Hauck RM, Skahen J III, Palmer AK. Classification and treatment of ulnar styloid non-union. J Hand Surg [Am]. 1996: 21(3): 418-22

17. Haugstvedt JR, Berger RA, Nakamura T et al. Relative contributions of the ulnar attachments of the triangular fibrocartilage complex to the dynamic stability of the distal radioulnar joint. J Hand Surg [Am]. 2006; 31(3): 445-51.

18. Kikuchi Y, Nakamura T. Avulsion fracture at the fovea of the ulna. A report of two cases. J Hand Surg [Br]. 1998; 23: 176–8.

19. May MM, Lawton JN, Blazar PE. Ulnar styloid fractures associated with distal radius fractures: inci-dence and implications for distal radioulnar joint instability. J Hand Surg Am. 2002; 27(6): 965–71.

20. Zimmermann R, Rudisch A, Fritz D et al. MR imaging for the evaluation of accompanying injuries in cases of distal forearm fractures in children and adolescents. Handchir Mikrochir Plast Chir. 2007; 39(1): 60–7.

21. Roysam GS. The distal radio-ulnar joint in Colles’ fractures, J Bone Joint Surg. 1993; 75B: 58–60. 22. Stoffelen D, De Smet L, Broos P. The importance of the distal radioulnar joint in distal radial frac-

tures, J Hand Surg 1998; 23B: 507–11. 23. Zenke Y, Sakai A, Oshige T et al. The effect of an associated ulnar styloid fracture on the outcome

after fixation of a fracture of the distal radius, J Bone Joint Surg. 2009; 91B: 102–7.

Chapter 1

22

24. Villar RN, Marsh D, Rushton N et al. Three years after Colles’ fracture: A prospective review, J Bone Joint Surg 1987; 69B: 635–8.

25. af Ekenstam F, Jakobsson OP, Wadin K. Repair of the triangular ligament in Colles’ fracture: no effect in a prospective randomized study. Acta Orthop Scand 1989; 60: 393-396

26. Kaukonen JP, Karahuarju EO, Porras M et al. Functional recovery after fractures of the distal fore-arm. Analysis of radiographic and other factors affecting the outcome. Ann Chir Gynaecol. 1988; 77(27): 27-31

27. Melone CP, Nathan R. Traumatic disruption of the triangular fibrocartilage complex. Clin Orthop 1992; 275: 65-73

28. Tsukazaki T, Iwasaki K. Ulnar wrist pain after Colles’ fracture. Acta Orthop Scand 1993; 64: 462-4 29. Buijze G, Ring D. Clinical impact of united versus nonunited fractures of the proximal half of the

ulnar styloid following volar plate fixation of the distal radius. J Hand Surg [Am] 2010; 35(2): 223-7 30. Kim JP, Park MJ. assessment of distal radioulnar joint instability after distal radius fracture: com-

parison of computed tomography and clinical examination results. J Hand Surg [Am] 2008; 33(9): 1486-94

31. Souer JS, Ring D, Matschke S et al. Effect of an unrepaired fracture of the ulnar styloid base on outcome after plate-and-screw fixation of a distal radial fracture. J Bone Joint Surg [Am] 2009; 91(4): 830-8

32. Altissimi M, Antenucci R, Fiacca C, et al. Long-term results of conservative treatment of fractures of the distal radius. Clin Orthop Relat Res. 1986; 206: 202-10.

33. Nellans KW, Kowalski E, Chung KC. The epidemiology of distal radius fractures. Hand Clin. 2012; 28: 113-25.

34. Taras JS, Ladd AL, Kalainov DM, et al. New concepts in the treatment of distal radius fractures. Instr Course Lect. 2010; 59: 313-32.

35. White JS. Fractures of the distal radius. Adv Emerg Nurs J. 2013; 35: 8-15 36. Jupiter JB. Commentary: The effect of ulnar styloid fractures on patient-rated outcomes after

volar locking plating of distal radius fractures. J Hand Surg [Am] 2009; 34(9): 1603-4. 37. Mino DE, Palmer AK, Levinsohn EM. The role of radiography and computed tomography in the

diagnosis of subluxation and dislocation of the distal radioulnar joint. J Hand Surg [Am] 1983; 8(1): 23-31.

38. Nakamura R, Horii E, Imaeda T et al. Distal radioulnar joint subluxation and dislocation diagnosed by standard roentgenography. Skeletal Radiol 1995; 24(2): 91-4.

39. Pirela-Cruz MA, Goll SR, Klug M et al. Stress computed tomography analysis of the distal radioul-nar joint; a diagnostic tool for determining translational motion. J Hand Surg Am. 1991; 16: 75-82

40. Nakamura R, Horii E, Imaeda T et al. Criteria for diagnosing distal radioulnar joint subluxation by computed tomography. Skeletal Radiol 1996; 25(7): 649-53.

41. Johnston GHF, Friedman L, Kriegler JC. Computerized tomographic evaluation of acute distal radial fractures. J Hand Surg 1992; 17A: 737-44.

42. Pruitt DL, Gilula LA, Manske PR, et al. Computed tomography scanning with image reconstruction in evaluation of distal radius fractures. J Hand Surg 1994; 19A: 720-7.

43. Rozental TD, Bozentka DJ, Katz MA, et al. Evaluation of the sigmoid notch with computed tomog-raphy following intra-articular distal radius fracture. J Hand Surg [Am] 2001; 26A: 244-51.

44. Lo IK, MacDermid JC, Bennett JD et al. The radioulnar ratio: a new method of quantifying distal radioulnar joint subluxation. J Hand Surg [Am] 2001; 26(2): 236-43.

23


1 45. Mino DE, Palmer AK, Levinsohn EM. Radiography and computerized tomography in the diagnosis

of incongruity of the distal radio-ulnar joint. A prospective study. J Bone Joint Surg [Am] 1985; 67(2): 247-52.

46. Wechsler RJ, Wehbe MA, Rifkin MD et al. Computed tomography diagnosis of distal radioulnar subluxation. Skeletal Radiol 1987; 16(1): 1-5

47. Park MJ, Kim JP. Reliability and normal values of various computed tomography methods for quantifying distal radioulnar joint translation. J Bone Joint Surg [Am] 2008; 90(1): 145-53.

48. Pogue DJ, viega FS, Patterson RM, et al. Effects of distal radius fracture malunion on wrist joint mechanics. J Hand Surg [Am] 1990; 15(5): 721-7

49. Watanabe H, Berger RA, Berglund LJ, et al. contribution of the interosseous membrane to distal radioulnar joint constraint. J Hand Surg [Am] 2005; 30(6): 1164-71

50. Orbay JL, Badia A, Indriago IR et al. The Extended Flexor Carpi Radialis Approach: A New Perspec-tive for the Distal Radius Fracture. Tech Hand Up Extrem Surg. 2001; 5(4): 204-11.

51. Lawler E, Adams BD. Reconstruction for DRUJ instability. Hand (NY) 2007; 2: 123-6. 52. Scheker LR, Belleiappa PP, Acosta R et al. Reconstruction of the dorsal ligament of the triangular

fibrocartilage complex. J Hand Surg [Br] 1994; 19: 310-8. 53. Breen TF, Jupiter JB. Extensor carpi ulnaris and flexor carpi ulnaris tenodesis of the unstable distal

ulna. J Hand Surg [Am] 1989; 14: 612-7. 54. Hui FC, Linscheid RL. Ulnotriquetral augmentation tenodesis: a reconstructive procedure for

dorsal subluxation of the distal radioulnar joint. J Hand Surg [Am] 1982; 7: 230-6. 55. Tsai TM, Stilwell JH. Repair of chronic subluxation of the distal radioulnar joint (ulnar dorsal) using

flexor carpi ulnaris tendon. J Hand Surg [Br] 1984; 9: 289-94. 56. Kapandji I. The Kapandji-Sauve operation. Its techniques and indications in non rheumatoid

diseases. Ann Chir Main. 1986; 5: 181-93. 57. Watson H, Gabuzda G. Matched distal ulna resection for posttraumatic disorders of the distal

radioulnar joint. J Hand Surg. 1992; 17A: 724-30. 58. Bowers W. Distal radioulnar joint arthroplasty: the hemiresection-interposition technique. J Hand

Surg. 1985; 10A: 169-78. 59. Chun S, Palmer A. The ulnar impaction syndrome: follow-up of ulnar shortening osteotomy. J

Hand Surg. 1993; 18A: 46-53. 60. Feldon P, Terrono A, Belsky M. The “wafer” procedure. Partial distal ulnar resection. Clin Orthop.

1992; 275: 124-9. 61. Darrach W. Anterior dislocation of the head of the ulna. Ann Surg 1912; 56: 802-3. 62. Bell M, Hill R, McMurtry R. Ulnar impingement syndrome. J Bone Joint Surg 1985; 67B: 126-9. 63. Bieber E, Linscheid R, Dobyns J et al. Failed distal ulna resections. J Hand Surg 1988; 13A: 193-200. 64. Ekenstam F, Engkvist O, Wadin K. Results from resection of the distal end of the ulna after fractures

of the lower end of the radius. Scand J Plast Reconstr Surg 1982; 16: 177-81. 65. Field J, Majkowski R, Leslie I. Poor results of Darrach’s procedure after wrist injuries. J Bone Joint

Surg 1993; 75B: 53-7. 66. George M, Kiefhaber T, Stern P. The Sauve-Kapandji procedure and the Darrach procedure for

distal radio-ulnar joint dysfunction after Colles’ fracture. J Hand Surg 2004; 29B: 608-13. 67. McKee M, Richards R. Dynamic radio-ulnar convergence after the Darrach procedure. J Bone Joint

Surg 1996; 78: 413-8 68. Minami A, Iwasaki N, Ishikawa J et al. Treatments of osteoarthritis of the distal radioulnar joint:

long-term results of three procedures. Hand Surg 2005; 10: 243-8.

12345678910111213

Chapter 2Clinical and non-clinical aspects of distal radioulnar

joint instability

Chapter 2

26

M.M.E. Wijffels, P.R.G. Brink, I.B. Schipper

The Open Orthopaedics Journal, 2012, 6, 204-210

ABSTRACT

Untreated distal radioulnar joint (DRUJ) injuries can give rise to long lasting complaints. Although common, diagnosis and treatment of DRUJ injuries remains a challenge. The articulating anatomy of the distal radius and ulna, among others, enables an extensive range of forearm pronosupination movements. Stabilization of this joint is provided by both intrinsic and extrinsic stabilizers and the joint capsule. These structures transmit the load and prevent the DRUJ from luxation during movement. Several clinical tests have been suggested to determine static or dynamic DRUJ stability, but their predic-tive value is unclear. Radiologic evaluation of DRUJ instability begins with conventional radiographs in anterioposterior and true lateral view. If not conclusive, CT-scan seems to be the best additional modality to evaluate the osseous structures. MRI has proven to be more sensitive and specific for TFCC tears, potentially causing DRUJ instability. DRUJ instability may remain asymptomatic. Symptomatic DRUJ injuries treatment can be conservative or operative. Operative treatment should consist of restoration of osse-ous and ligamentous anatomy. If not successful, salvage procedures can be performed to regain stability.

27

Clinical and non-clinical aspects of distal radioulnar joint instability

2

INTRODUCTION

Traumatic injuries to the distal radioulnar joint (DRUJ) may give rise to long lasting complaints of pain and restricted function in the wrist and hand. Solitary DRUJ injuries are common, although they more often accompany distal radius fractures. Diagnosis and treatment of DRUJ injuries remain challenging. A high index of suspicion, effec-tive diagnostic procedures and knowledge of the anatomical stabilizing structures are prerequisites for adequate diagnosis and treatment. This paper provides an overview of anatomy, clinical presentation, radiologic evaluation and treatment options related to stability and instability of the DRUJ.

ANATOmY

The distal radioulnar articulation is formed by the distal sides of the radius and the ulna, the sigmoid notch and ulnar seat, respectively (Figure 2.1a). Due to the parallel position-ing of the surfaces, with a difference in articulating curvature, the DRUJ provides pro- and supination in an extensive range, but yields stabilization (Figure 2.1b).1 The DRUJ obtains

Figure 2.1a. The distal radioulnar articulation is formed by the distal sides of the radius and the ulna, the sigmoid notch and ulnar seat (A) re-spectively. The inclination of the radius (striped line) differs from the ulnar inclination. S = scaph-oid bone, L = lunate bone, T = triquetral bone.

Figure 2.1b. The ulnar seat has a smaller radius (small circle) compared to the sigmoid notch (large circle).

Chapter 2

28

stabilization from the joint capsule, the triangular fibrocartilage complex (TFCC) and the capsule surrounding structures. The capsule is a tripartite structure, continuous with the radioulnar ligaments of the TFCC and the floor of the extensor carpi ulnaris (ECU) tendon sheet. Although closely associated with surrounding structures, the capsule remains an autonomous structure. Inferiorly the capsule originates from the proximal border of the sigmoid notch and is continuous with the interosseous membrane (IM). On the volar side the capsule comprises thin areas, adapting to dorsal translation of the radius dur-ing supination. Volarly the capsule is continuous with the radioulnar ligaments of the TFCC. Reinforcing oblique fibres, among others, protect the radius from dorsal luxation. Dorsally, on the ulnar side, the capsule is in intimate contact with the ECU sheet and has reinforcing fibres at its insertion on the radial aspect of the ulna.2

Extracapsular anatomy

The musculus extensor carpi ulnaris (ECU) is located on the dorso-medial side of the forearm. The ECU tendon inserts at the base of the 5th metacarpal and transverses the ulnocarpal joint through a fibro-osseous tunnel (sixth dorsal compartment), attached to the ulnar head (Figure 2.2).3

Figure 2.2. The main extracapsular stabilizers of the DRU joint with one of the three reinforced areas of the interosseous membrane.

29


2

The musculus pronator quadratus (MPQ) is situated on the volar side of the wrist, sur-rounded by a thin fascia. The distal insertion of the MPQ fascia is the prominent palmar crest on the radius and the articular border of the ulna where it assembles the joint capsule. On the ulnar side, the MPQ develops two heads. The superficial head inserts on the medial intermuscular septum on the ulna. The deep head of the MPQ is in direct con-tact with the IM.4 The IM originates on the radius and inserts on the ulna, approximately 6 centimetres distal from the radial head. It is continuous with the DRUJ capsule and contains three reinforced regions. These regions are mainly responsible for the stability in longitudinal and transverse directions. Besides serving as a forearm stabilizer, the IM serves as the origin for flexors and extensors of the wrist.5

TFCC

The TFCC consists of five parts; the articular disc, the superficial and deep (ligamentum Subcruentum) radioulnar fibers, and the two disc-carpal ligaments (Figure 2.3).6 The disc is a strong fibrocartilage structure, stretched between ulna and radius proximally and lunate and triquetral bones distally. The base of the disc is attached to the distal edge of the sigmoid notch; the incisura ulnaris radii. The apex of the disc is inserted to

Figure 2.3. The triangular fibrocartilage complex. The disc (not drawn in this figure) is stretched between ulna and radius proximally and lunate and triquetral bones distally. The two ulno-carpal ligaments are the ligaments that are partially resected in this figure.

Chapter 2

30

the depressed area of the ulnar head; the basistyloid fovea. It is continuous with the ulnar collateral ligament. On the volar side the disc is continuous with the ulnocarpal ligament, inserting on the lunate, triquetral and capitate bones.7,8 The dorsal and palmar radioulnar fibers originate from the medial border of the distal radius and insert on the ulna at two distinct sites; deep fibers at the ulnar fovea and superficial fibers at the ulnar styloid (Figure 2.4).

BIOmECHANICS

Pronosupination

The four primary components of the ‘forearm joint’: the radiocapitellar joint, the proximal radioulnar joint, the IM and the DRUJ allow 180° of pro- and supination of the forearm. With the radius rotating around the fixed ulna, in maximum pronation of 90°, the two forearm bones are essentially parallel and the interosseous space will be at maximum width. The rotational movement gives rise to a translational movement of the radius relative to the distal ulna. In supination the ulnar head is positioned relative palmar and in pronation relative dorsal, to the radius. These combined movements result in a complex anatomical area, called the “centrode of rotation”, rather than a single center of rotation on the ulnar fovea.9,10 The biomechanics of DRUJ instability therefor primarily concern the dislocation of a rotating radius around a fixed ulna. Contrary to what is often thought, it is not the ulna that is dislocating.

Figure 2.4. The dorsal and palmar radioulnar fibers originate from the medial border of the distal radius and insert on the ulna at two distinct sites; deep fibers at the ulnar fovea and superficial fibers at the ulnar styloid.

31


2

Stability

Stability is defined as equality of forces, with their specific moments, working on a fixed fulcrum. When load is applied on the hand, the fixed fulcrum is the DRUJ (Figure 2.5). To resist gravity, stability of the elbow and DRUJ is needed. Focusing on the DRUJ, this stability is provided extrinsic, by extracapsular structures and intrinsic, by intracapsular structures. Extrinsic stability is provided by (1) the ECU tendon with its semi rigid sixth dorsal compartment3,11, (2) the musculus pronator quadratus12 and (3) the interosseous membrane.13 Tensioning of the ECU tendon and MPQ in supination results in increased DRUJ stability.3,9,11,14 The distal oblique fibers of the IM prevent the distal radius from luxation during rotation.5,13,15-19

The primary intrinsic stabilizer of the DRUJ is the TFCC, predominantly the radioulnar ligaments of the TFCC. Additional stability is provided by the DRUJ capsule, which allows pronosupination without anterioposterior luxation. Early theories about the effect of the TFCC on DRUJ stability, suggested unique, non-collaborating roles for both deep and superficial radioulnar fibers.1,20 Hagert stated that in pronation, the dorsal superficial

Figure 2.5. When load is applied to the hand (F) with a specific moment (L), the fixed fulcrum (E) is the DRUJ. Stability is defined as equality in forces, with their specific moments, working on a fixed fulcrum. If the elbow is stable, the load between elbow and DRUJ (F’ x L’) will equal the load between the DRUJ and the hand (F x L) in a stable situation.

Figure 2.6a. When the radius rotates around the ulna in pronation, the dorsal superficial fibers tight-en, as do the deep palmar fibers.

Figure 2.6b. When the radius rotates around the ulna in supination, the palmar superficial radioulnar fibers tighten, as do the deep dorsal fibers.

Chapter 2

32

fibers tighten, as do the deep palmar fibers. Conversely, in supination, the palmar superficial radioulnar fibers tighten, as do the deep dorsal fibers (Figure 2.6a, b).10

A less important mechanism of DRUJ stabilization, is the shift of the principal axis of load bearing. In maximal pronation and supination, the dorsal and volar radioulnar capsule respectively prevent the ulna from luxation.1

CLINICAL PRESENTATION OF RADIOULNAR INSTABILITY

Although the radius is rotating around the ulna, ulnar dislocation is described, by convention, relative to the radius.21 Suspicion of DRUJ instability should increase after a history of wrist trauma, and restricted or painful pro- and supination. In specific cases of solitary distal ulna luxation the empty sulcus or groove for the ECU tendon can be palpated, in maximal supination on the head of the ulna. This is due to the ECU and the TFCC which are displaced into the DRUJ.22 Acute DRUJ instability accompanying a distal radius fracture, will be difficult to diagnose due to the swelling and deformity around the wrist joint. In chronic DRUJ instability, volar translation of the ulnar head is most frequently due to radial malunion, rather than to instability.23

Figure 2.7. The stress-test is performed by provoking anterolateral movement of the radius, while stabiliz-ing the ulna. By comparing the stability of both the injured with the non-injured wrist, DRUJ instability can be diagnosed.

33


2

Testing Instability

In testing the DRUJ, a distinction should be made between static and dynamic instabil-ity. Static instability is defined as laxity of the DRUJ with a non-rotating distal radius, as compared to the unaffected side. Dynamic instability can only be tested during forearm rotation. Only a small number of physical tests for determining DRUJ instability have been described. (Table 2.1).

The stress test for static DRUJ instability (Figure 2.7), also known as the “piano sign” or ballottement maneuver, is mostly used but its diagnostic value remains disputed.16,23-25 The radius pull test, as described by Essex-Lopresti, can diagnose longitudinal forearm instability.26-28

Dynamic DRUJ instability can be diagnosed using the clunk test or the extensor carpi ulnaris test.16,29 Presence of TFCC-lesions can be tested using the press-test.30 The clinical value of the press-test is unclear, since not every TFCC tear is associated with DRUJ in-stability.31,32 Furthermore the correlation between physical examination and radiologic outcome remains unclear.33

Table 2.1. Different methods for testing DRUJ instability. Each test is explained and their specific charac-teristics are described

Name How to Perform Positive if: Tested Stabilizer Sensitivity (%)

Specificity (%)

Stress test/ballottement

Elbowflexion 90°, fingers to the ceiling. Dorsopalmar

movement of the ulna in respect to the radius in maximal pronation and

supination

Painful or DRUJlaxity

Palmar and dorsal lig. subcruentum

66 68

Radius pull test

Elbowflexion 90°, wrist in neutral position, pulling

the radius in longitudinal direction

Ulnar variance increases

during pulling under fluoroscopy

Interosseous membrane

Up to 100 in cadaveric

studies

Up to 100 in cadaveric

studies

Clunk test Compress ulna to the radius during passive

pronosupination

A clunk is palpable for the patient

Interosseous membrane

Not available

Not available

ECU test Elbowflexion 90°, hand in ulnar deviation, active

pronosupination

Abnormal motion

ECU tendon

ECU tendon Not available

Not available

Press test Patient pushes himself up from seated position with

use of affected wrist

Focal ulnar sided wrist

pain

TFCC 100 Not available

Chapter 2

34

Radiological evaluation

Conventional RadiographsAnterioposterior (AP) and true lateral radiographs of both wrists should be made to compare the injured with the uninjured side. Secure positioning is essential in this respect. Projection of the pisiform bone over the distal part of the scaphoid indicates a pure lateral view.34,35 A direct radiographic sign that indicates DRUJ instability, is widen-ing of the distal radioulnar space on the AP radiograph, relative to the unaffected side. On the true lateral view a radioulnar distance of 6mm or more, between the most dorsal cortices, indicates DRUJ instability. If this distance measures 4 to 5 mm then further investigation is needed.36 Indirect signs, that may indicate DRUJ instability, are an ulnar styloid base fracture, 15° or more dorsal tilting of the distal radius, avulsion of the ulnar fovea, radial shortening of more than 4 mm. and a radial inclination less than 0°.37,38

ArticulogramRadiopaque liquids injected intra-articularly, with repeated or continuous radiographs, facilitate visualization of the articular ligamentous borders. Articulograms of the wrist will only provide indirect signs that may account for DRUJ instability.39 Nowadays the articulogram is little used, due to the introduction of magnetic resonance imaging.

Computed TomographyWhen conventional radiographs are inconclusive, computed tomography scan (CT scan) can be of additional value in diagnosing DRUJ instability.40 A diagnostic protocol should include imaging of both wrists in maximal pronation, neutral position and maximal supination. Several techniques to define (sub)luxation have been suggested. The sub-luxation ratio method has been proven to be most useful.41-45 CT has its advantages in detecting DRUJ instability, but malunions may account for a false positive outcome.

Magnetic Resonance ImagingCompared to CT scan, magnetic resonance (MR) has greater sensitivity for soft tissue contrast but provides less osseous details. Several techniques have been suggested to define DRUJ instability using MR.46 High resolution MRI provides a potential tool for diagnosing ulnar styloid fractures and TFCC tears, however the role of MR in evaluating direct signs of DRUJ instability remains unclear.47,48

ArthroscopyArthroscopy has become popular when diagnosing TFCC tears, that may account for DRUJ instability, and their subsequent treatment. Furthermore, arthroscopy is sensitive

35


2

in the evaluation of the articulating surfaces of the distal radius and ulna as part of treat-ment strategy.49

Classification

Only one classification can be found for DRUJ instability. Seo and colleagues suggested a classification based on the outcome of the stress test.50 Operative treatment is pre-dominantly reserved for symptomatic laxity or spontaneous subluxation of the DRUJ.

TREATmENT

Before considering operative treatment of DRUJ instability, patients’ symptoms must be evaluated thoroughly. Painless DRUJ instability occurs in about one third of the patients after a distal radius fracture.24 In asymptomatic DRUJ instability, a “wait and see” policy can be advocated.24,31 If symptomatic DRUJ dislocation is diagnosed, conservative treat-ment will only be successful in the presence of a congruent DRUJ.

An acute dorsal dislocation can be reduced with digital pressure on the distal ulna combined with forceful supination. A full-arm cast should be maintained for 6 weeks. Conclusive evidence for the preferred wrist position is lacking.51,52 An acute volar dislo-cation should be reduced with digital pressure on the volar side in forceful pronation. Indications for operative treatment are interposition of soft tissue preventing manual reduction, a locked DRUJ or persisting DRUJ instability due to a fracture of the volar lip of the sigmoid notch.53 Open reduction techniques are described by Gibson and Cox.54,55 Lesions in the IM, as seen in Essex-Lopresti injury, need stabilization of both the radial head and the DRUJ.

Chronic DRUJ instability can be treated by functional bracing if patients are unwilling or unfit for surgery.56 For operative treatment of chronic DRUJ instability, both anatomical and non-anatomical techniques can be used. The first step in anatomic reconstruction consists of analysis of osseous alignment. Malalignment needs to be corrected if pres-ent. However, the need for re-insertion of a fractured or non-united ulnar styloid base is still a matter of debate. The second step is reconstruction of the intrinsic and extrinsic stabilizing structures, which can be done with open or arthroscopic procedures. When it is not possible to reconstruct the stabilizers, non-anatomic stabilization, using the surrounding tendons, may be indicated.57,58 In general, results of non-anatomic treat-ment options, such as tenodesis using the flexor carpi ulnaris or the ECU tendon, are disappointing.59-61 If non-anatomic DRUJ reconstructions give rise to complaints, several salvage procedures or ulnar head replacement have been suggested.62-67

Chapter 2

36

CONCLUSION

DRUJ instability is a common but frequently missed diagnosis. It is mostly associated with distal radius fractures. A malpositioned or lax distal ulna during physical examina-tion, must give rise to suspicion of DRUJ instability. The presence of direct or indirect signs on conventional roentgenography may indicate DRUJ instability as well. Currently, CT scans are favored for further osseous radiologic evaluation, as is MR for ligamentous evaluation. If DRUJ instability is present, only one classification can be referred to. In acute situations, non-operative treatment can be successful after anatomical reduction. In operative treatment, the first step is restoration of anatomy by correction of osseous malalignment, followed by soft tissue repair. If not successful, non-anatomical stability should be provided, otherwise salvage procedures should be carried out.

REFERENCES

1. Ekenstam F, Hagert CG. Anatomical studies on the geometry and stability of the distal radio ulnar joint. Scand J Plast Reconstr Surg 1985; (1): 17-25.

2. Kleinman WB, Graham TJ. The distal radioulnar joint capsule: clinical anatomy and role in post-traumatic limitation of forearm rotation. J Hand Surg Am 1998; 23(4): 588-99.

3. Spinner M, Kaplan EB. Extensor carpi ulnaris. Its relationship to the stability of the distal radio-ulnar joint. Clin Orthop Relat Res1970; 68: 124-9.

4. Gerber A, Masquelet AC. Anatomy and intracompartmental pressure measurement technique of the pronator quadratus compartment. J Hand Surg Am 2001; 26(6): 1129-34.

5. Poitevin LA. Anatomy and biomechanics of the interosseous membrane: its importance in the longitudinal stability of the forearm. Hand Clin 200; 17(1): 97-110.

6. Mikic ZD. Detailed anatomy of the articular disc of the distal radioulnar joint. Clin Orthop Relat Res 1989; 245: 123-32.

7. Bednar MS, Arnoczky SP, Weiland AJ. The microvasculature of the triangular fibrocartilage com-plex: its clinical significance. J Hand Surg Am 1991; 16(6): 1101-5.

8. Thiru RG, Ferlic DC, Clayton ML et al. Arterial anatomy of the triangular fibrocartilage of the wrist and its surgical significance. J Hand Surg Am 1986; 11(2): 258-63.

9. King GJ, McMurrey RY, Rubenstein JD et al. Kinematics of the distal radioulnar joint. J Hand Surg Am 1986; 11(6): 798-804.

10. Hagert CG. Distal radius fracture and the distal radioulnar joint -anatomical considerations. Handchir Mikrochir Plast Chir 1994; 26(1): 22-6.

11. Goldner JL, Hayes MG. Stabilization of the remaining ulna using one-half of the extensor carpi ulnaris tendon after resection of the distal ulna. Orthop Trans 1979; 3: 330-1.

12. Ruby LK, Ferenz CC, Dell PC. The pronator quadratus interposition transfer: an adjunct to resec-tion arthroplasty of the distal radioulnar joint. J Hand Surg Am 1996; 21(1): 60-5.

13. Hotchkiss RN, An KN, Sowa DT, et al. An anatomic and mechanical study of the interosseous membrane of the forearm: pathomechanics of the proximal migration of the radius. J Hand Surg Am 1989; 14(2 Pt 1): 256-61.

37


2

14. Palmer AK, Werner FW. The triangular fibrocartilage complex of the wrist-anatomy and function. J Hand Surg Am 1981; 6(2): 153-62.

15. Gofton WT, Gordon KD, Dunning CE et al. Soft tissue stabilizers of the distal radioulnar joint: an in vitro kinematic study. J Hand Surg Am 2004; 29(3): 423-31.

16. Jupiter JB. Commentary: The effect of ulnar styloid fractures on patient-rated outcomes after volar locking plating of distal radius fractures. J Hand Surg Am 2009; 34(9): 1603-4.

17. Noda K, Goto A, Murase T et al. Interosseous membrane of the forearm: an anatomical study of ligament attachment locations. J Hand Surg Am 2009; 34(3): 415-22.

18. Pfaeffle HJ, Manson TT, Tomaino MM et al. Role of the forearm interosseous ligament: is it more than just longitudinal load transfer? J Hand Surg Am 2000; 25(4): 683-8.

19. Watanabe H, Berger RA, Berglund LJ et al. Contribution of the interosseous membrane to distal radioulnar joint constraint. J Hand Surg Am 2005; 30(6): 1164-71.

20. schuind F, An KN, Berglund L, et al. The distal radioulnar ligaments: a biomechanical study. J Hand Surg Am 1991; 16(6): 1106-14.

21. Dameron TB Jr. Traumatic dislocation of the distal radio-ulnar joint. Clin Orthop Relat Res 1972; 83: 55-63.

22. Paley D, McMurry RY, Murray JF. Dorsal dislocation of the ulnar styloid and extensor carpi ulnaris tendon in the distal radioulnar joint: The empty sulcus sign. J Hand Surg Am 1987; 12(6): 1029-32.

23. Kim JP, Park MJ. assessment of distal radioulnar joint instability after distal radius fracture: com-parison of computed tomography and clinical examination results. J Hand Surg Am 2008; 33(9): 1486-94.

24. Lindau T, Hagbert L, Aldercreutz C et al. Distal radioulnar instability is an independent worsening factor in distal radial fractures. Clin Orthop Relat Res 2000; 376: 229-35.

25. Szabo RM. Distal radioulnar joint instability. J Bone Joint Surg Am 2006; 88(4): 884-94. 26. Davidson PA, Moseley JB Jr., Trullos HS. Radial head fracture. A potentially complex injury. Clin

Orthop Relat Res 1993; 297: 224-30. 27. Essex-Lopresti P. Fractures of the radial head with distal radio-ulnar dislocation; report of two

cases. J Bone Joint Surg Br 1951; 33B(2): 244-7. 28. Smith AM, Urbanosky LR, Castle JA et al. Radius Pull Test: Predictor of longitudinal forearm insta-

bility. J Bone Joint Surg Am 2002; 84-A(11): 1970-6. 29. Burkhartt SS, Wood MB, Lindscheid RL. Posttraumatic recurrent subluxation of the extensor carpi

ulnaris tendon. J Hand Surg Am1982; 7(1): 1-3. 30. Lester B, Halbrecht J, Levy IM et al. “Press test” for office diagnosis of triangular fibrocartilage

complex tears of the wrist. Ann Plast Surg 1995; 35(1): 41-5. 31. Lindau T, Adlercreutz C, Aspenberg P. Peripheral tears of the triangular fibrocartilage complex

cause distal radioulnar joint instability after distal radial fractures. J Hand Surg Am 2000; 25(3): 464-8.

32. Palmer AK. Triangular fibrocartilage disorders: injury patterns and treatment. Arthroscopy 1990; 6(2): 125-32.

33. Pirela-Cruz MA, Goll SR, Klug M et al. Stress computed tomography analysis of the distal radio-ulnar joint: a diagnostic tool for determining translational motion. J Hand Surg Am 1991; 16(1): 75-82.

34. Epner RA, Bowers WH, Guilford WB. Ulna variance-the effect of wrist positioning and roentgen filming technique. J Hand Surg Am 1982; 7(3): 298-305.

Chapter 2

38

35. Mino De, Palmer AK, Levinsohn EM. The role of radiography and computed tomography in the diagnosis of subluxation and dislocation of the distal radioulnar joint. J Hand Surg Am 1983; 8(1): 23-31.

36. Nakamura R, Horii E, Imaeda T et al. Distal radioulnar joint subluxation and dislocation diagnosed by standard roentgenography. Skeletal Radiol 1995; 24(2): 91-4.

37. Pogue DJ, Viegas FS, Patterson RM, et al. Effects of distal radius fracture malunion on wrist joint mechanics. J Hand Surg Am1990; 15(5): 721-7.

38. Watanabe H, Berger RA, Berglund LJ, et al. Contribution of the interosseous membrane to distal radioulnar joint constraint. J Hand Surg Am 2005; 30(6): 1164-71.

39. Levinsohn EM, Rosen ID, Palmer AK. Wrist arthrography: value of the three-compartment injec-tion method. Radiology 1991; 179(1): 231-9.

40. Mino DE, Palmer AK, Levinsohn EM. Radiography and computerized tomography in the diagnosis of incongruity of the distal radio-ulnar joint. A prospective study. J Bone Joint Surg Am 1985; 67(2): 247-52.

41. Lo IK, MacDermid JC, Bennett JD et al. The radioulnar ratio: a new method of quantifying distal radioulnar joint subluxation. J Hand Surg Am 2001; 26(2): 236-43.

42. Mino DE, Palmer AK, Levinsohn EM. The role of radiography and computed tomography in the diagnosis of subluxation and dislocation of the distal radioulnar joint. J Hand Surg Am 1983; 8(1): 23-31.

43. Nakamura R, Horii E, Imaeda T et al. Criteria for diagnosing distal radioulnar joint subluxation by computed tomography. Skeletal Radiol 1996; 25(7): 649-53.

44. Park MJ, Kim JP. Reliability and normal values of various computed tomography methods for quantifying distal radioulnar joint translation. J Bone Joint Surg Am 2008; 90(1): 145-53.

45. Wechsler RJ, Wehbe MA, Rifkin MD et al. Computed tomography diagnosis of distal radioulnar subluxation. Skeletal Radiol 1987; 16(1): 1-5.

46. Staron RB, Feldman F, Haramati N et al. Abnormal geometry of the distal radioulnar joint: MR findings. Skeletal Radiol 1994; 23(5): 369-72.

47. Anderson ML, Skinner JA, Felmlee JP et al. Diagnostic comparison of 1.5 Tesla and 3.0 Tesla preoperative MRI of the wrist in patients with ulnar-sided wrist pain. J Hand Surg Am 2008; 33(7): 1153-9.

48. Magee T. Comparison of 3-T MRI and arthroscopy of intrinsic wrist ligament and TFCC tears. AJR Am J Roentgenol 2009; 192(1): 80-5.

49. Atzei A. New trends in arthroscopic management of type 1-B TFCC injuries with DRUJ instability. J Hand Surg Eur Vol 2009; 34(5): 582-91.

50. Seo KN, Park MJ, Kang HJ. Anatomic reconstruction of the distal radioulnar ligament for post-traumatic distal radioulnar joint instability. Clin Orthop Surg 2009; 1(3): 138-45.

51. Garcia-Elias M, Dobyns JH. Dorsal and palmar dislocations of the distal radioulnar joint. In: Cooney WP, Ed. The wrist: diagnosis and operative treatment. St. Louis: Mosby 2010.

52. Linscheid RL. Disorders of the distal radioulnar joint. In: Cooney WP, Ed. The wrist: diagnosis and operative treatment. St. Louis: Mosby 1998.

53. Paley D, Rubenstein J, McMurrey RY. Irreducible dislocation of distal radial ulnar joint. Orthop Rev 1986; 15(4): 228-31.

54. Cox FJ. Anterior dislocation of the distal extremity of the ulna: report of a case. Surgery 1942; 12: 11-3.

55. Gibson A. Uncomplicated dislocation of the inferior radio-ulnar joint. J Bone Joint Surg 1925; 7: 80-9.

39


2

56. Millard GM, Budoff JE, Paravic V et al. Functional bracing for distal radioulnar joint instability. J Hand Surg Am 2002; 27(6): 972-7.

57. Lawler E, Adams BD. Reconstruction for DRUJ instability. Hand (NY) 2007; 2(3): 123-6. 58. Scheker LR, Belleiappa PP, Acosta R et al. Reconstruction of the dorsal ligament of the triangular

fibrocartilage complex. J Hand Surg Br 1994; 19 (3): 310-8. 59. Breen TF, Jupiter JB. Extensor carpi ulnaris and flexor carpi ulnaris tenodesis of the unstable distal

ulna. J Hand Surg Am 1989; 14(4): 612-7. 60. Hui FC, Linscheid RL. Ulnotriquetral augmentation tenodesis: a reconstructive procedure for

dorsal subluxation of the distal radioulnar joint. J Hand Surg Am 1982; 7(3): 230-6. 61. Tsai TM, Stilwell JH. Repair of chronic subluxation of the distal radioulnar joint (ulnar dorsal) using

flexor carpi ulnaris tendon. J Hand Surg Br 1984; 9(3): 289-94. 62. Bowers WH. Distal radioulnar joint arthroplasty: the hemiresection-interposition technique. J

Hand Surg Am 1985; 10 (2): 169-78. 63. Darrach W. Anterior dislocation of the head of the ulna. Ann Surg 1912; 56: 802-3. 64. Feldon P, Terrono AL, Belsky MR. The “wafer” procedure. Partial distal ulnar resection. Clin Orthop

Relat Res 1992; (275): 124-9. 65. Herbert T, van Schoonhoven J. Ulnar head replacement. Tech Hand Up Extrem Surg 2007; 11(1):

98-108. 66. Kapandji I. The Kapandji-Sauve operation. Its techniques and indications in non rheumatoid

diseases. Ann Chir Main 1986; 5(3): 181-93. 67. Watson H, Gabuzda G. Matched distal ulna resection for posttraumatic disorders of the distal

radioulnar joint. J Hand Surg Am 1992; 17(4): 724-30.

12345678910111213

Part IIRadiological aspects

12345678910111213

Chapter 3Inter-observer variation in the diagnosis of coronal

articular fracture lines in the lunate facet of the distal radius

Chapter 3

44

M.M.E. Wijffels, T.G. Guitton, D. Ring & Science of Variation Group

HAND (2012) 7:271–275

The Science of Variation group is composed of Ponsen KJ., Rocha S., Athwal G., Elmans L., Fanuele J., Sodha S., Swigart C., Barquet A., Cassidy C., Papandrea R., Shyam A., de Bedout R., Nolla J., Richard MJ., Hanel D., Poolman R., Wright T., Allan C., Rhemrev S., Gosens T., Baskies M., Grosso E., Swiontkowski M., Harris I., Boretto J., Brink P., Biert J., Osterman A. L., Schep N., Coles CP., Feibel RJ., Abrams R., Hughes T., Nelissen R., Ladd A., McAuliffe J., Duncan S., Beingessner D., Conflitti JM., Goslings JC., Crist B., Frihagen F., Dyer G., Page RS., Zalayras C., Jeray K., Jebson P., Thomas G., Kalainov D., Hammerberg EM., Chen N., Pesantez R., Taras J., Goldfarb C., Prayson M., Zura R., Richardson M., Boyer M., Ilyas A., Fasrsr., Kloen P., Evans PJ., and Segalman K.

ABSTRACT

Background: Several studies support the use of CT for diagnosing coronal fractures of the distal radius but the interobserver reliability of these observations is less well studied. We tested the null hypothesis that radiographs alone and the combination of radiographs and two-dimensional computed tomography scans (2DCT) have the same inter-observer variation for the diagnosis of coronal articular fracture lines in the distal radius.Methods: Using a web-based survey, 63 surgeons were randomized to evaluate 16 frac-tures of the distal radius on radiographs alone or radiographs and 2DCT for the presence or absence of a coronal fracture line of the lunate facet and, if present, the stability of the fracture. The kappa multirater measure was calculated to estimate agreement between observers.Results: The inter-observer variation in diagnosis of a coronal fracture line was fair with both radiographs and 2DCT, as was the diagnosis of instability of the volar lunate facet fracture when present.Conclusion Two-dimensional computed tomography does not improve observer agree-ment on the diagnosis of coronal plane articular fracture lines in the lunate facet of the distal radius.

45

Inter-observer variation in the diagnosis of coronal articular fracture lines in the lunate facet of the distal radius

3

INTRODUCTION

Melone emphasized the importance of a coronal split in the lunate facet of the distal radius, suggesting that an unstable volar fragment would require open reduction and internal fixation and could not be managed percutaneously.6 Such fractures also involve the distal radioulnar joint.1,3 It has been suggested that computed tomography aids identification of coronal fracture lines. Rozental and colleagues identified an articular fracture involving the distal radioulnar joint (DRUJ) on 13 of 20 CT scans, but only on seven of 20 radiographs.4, 9, 10 These data support the use of CT for diagnosing coronal fractures of the distal radius, but the inter-observer reliability of these observations has not been studied.

A new collaboration motivated to better understand inter-observer variation consists of observers that have completed all training and are independently treating patients (www.scienceofvariationgroup.nl). This provides an opportunity to further investigate inter-observer variability and how to reduce it.

This study tested the null hypothesis that the combination of radiographs and two-dimensional computed tomography scans (2DCT) has the same inter-observer variation as radiographs alone in the diagnosis of coronal articular fracture lines.

mATERIALS AND mETHODS

Study design

Independent observers (all orthopedic surgeons) from several countries were invited to evaluate 16 distal radius fractures in an online survey. Participants were randomly assigned on a 1:1 basis to review either radiographs alone or radiographs and 2DCT to identify a coronal fracture of the lunate facet and to determine its stability. The study was performed under a protocol approved by the Institutional Research Board at the principal investigators hospital.

The Science of Variation group uses internet survey software to facilitate large interna-tional inter-observer studies. With multiple fully trained surgeons from diverse countries and institutions participating in studies, this approach should provide a powerful and externally valid forum for studying, understanding, and ultimately reducing inter-observer variation in aspects of patient care.

Observers

A total of 206 surgeons were invited via e-mail to join the Science of Variation Group. Other than an acknowledgement as part of the author collaborative in the paper, no incentives were provided. Sixty-three surgeons were interested in participation and

Chapter 3

46

logged on to the website. Thirty-three surgeons were randomized to conventional ra-diographs and 30 to radiographs with additional 2DCT scans using a computer random number generator. Group members that agreed to participate were sent the appropri-ate link after randomization. Three surgeons were excluded because of incomplete answers; two in the CT group and one in the radiograph group. Four weekly reminders to complete the online survey were e-mailed. This study presents an analysis of the 60 observers that completed the study; 31 in the radiograph group and 29 in the radio-graph with 2DCT group.

Fractures

Radiographs and computed tomography scans of distal radius fractures were identified from a consecutive list of 355 cases treated by the senior investigator between 2001 and 2006 at one level-1 trauma center. Inclusion criteria were (1) articular fracture of the distal radius fractures with adequate quality radiographs (posteroanterior and lateral views with no plaster or other obscuring features) and 2DCT (slice thickness less than 1 mm); and (2) Age 18 or older. Radiographs and CT scans of 16 articular fractures of the distal radius, eight with a coronal articular fracture line in the lunate facet, were blinded by an independent research fellow for use in this study. The fractures were all C-type fractures classified according to the Comprehensive Classification of Fractures.7 For each case, videos with 2DCT images along the sagittal and axial axes were created. Observers could scroll through the videos or play them automatically. Radiographs and 2DCT scans were uploaded to the research group’s website (Figure 3.1).

Evaluation

Observers logged in independently on the website. Upon login to the website, they were asked the number of distal radius fractures treated per year. Subsequently, observ-ers were asked for (1) the presence of an intra-articular fracture line in the coronal plane and (2) if present, is this fracture unstable?

Observers were blinded to clinical information. Observers had the option to comment on each case and all questions had to be completed in order to continue with the next case. The observers completed the study at their own time and pace.

Statistical analysis

The multirater kappa measure (κ) was used to estimate agreement among surgeons with respect to (1) presence of a fracture in the coronal plane and (2) the stability of this fracture. It is a commonly used statistic to describe chance-corrected agreement in a variety of intra-observer and interobserver studies.2,5,8 Agreement among observ-ers was calculated with use of the multirater kappa measure described by Siegel and Castellan.11 Kappa values were interpreted using the guidelines proposed by Landis

47


3

and Koch5: values of 0.01–0.20 indicate slight agreement; 0.21–0.40, fair agreement; 0.41–0.60, moderate agreement; 0.61–0.80, substantial agreement; and more than 0.81, almost perfect agreement. Zero indicates no agreement beyond that expected due to chance alone, −1.00 means total disagreement, and +1.00 represents perfect agree-ment.5,8 The agreement based on radiographs (κR) was compared to the agreement based on radiographs with 2DCT (κCT) using Z tests, which assume that the two samples are independent. Since the samples compared in this study were not independent (the same set of patients were rated by the radiographs and radiographs with 2DCT group), this method produced conservative estimates of the p values. The study had 80 % power to detect a difference in kappa scores of 0.1 between results based on radiographs vs. radiographs with 2DCT.

Figure 3.1. Example of radiograph with CT-scan uploaded to the research group’s website. These radio-graphs and CT scan were evaluated as a coronal fracture being present by all raters, but only 29 of 31 raters, only using radiographs, evaluated a coronal fracture being present

Chapter 3

48

RESULTS

Surgeons

Thirty-five (58 %) observers practiced in USA, 12 (20 %) in Continental Europe, three (5 %) in Canada, three (5 %) in Australia, two (3 %) in Asia, and five (8 %) in Latin America. Nineteen (32 %) observers had been in independent practice for fewer than 5 years, 12

Table 3.1. Observer demographics

Radiographs (N=31) Radiographs + 2DCT (N = 29)

Total (N=60)

N % N % N %

Gender Male 29 94 26 90 55 92

Female 2 6 3 10 5 8

Practice

Asia 1 3 1 3 2 4

Australia 2 6 1 3 3 5

Canada 0 0 3 10 3 5

Europe 4 13 8 28 12 20

UK 0 0 0 0 0 0

USA 22 71 13 45 35 58

Other 2 6 3 10 5 8

Years in practice

0-5 7 23 12 41 19 32

6-10 9 29 3 10 12 20

11-20 13 42 8 28 21 35

21-30 2 6 6 21 8 13

Supervise

Yes 29 94 26 90 55 92

No 2 6 3 10 5 8

Fractures per year

0-5 3 10 0 0 3 5

6-10 2 6 1 3 3 5

11-20 2 6 6 21 8 13

>20 24 78 22 76 46 77

Specialization

General orthopedics 0 0 1 3 1 2

Orthopedic traumatology 11 35 11 38 22 37

Shoulder and elbow 7 23 3 10 10 17

Hand and wrist 10 32 12 41 22 37

Others 3 10 2 7 5 8

49


3

(20 %) for 5–10 years, 21 (35 %) for 11–20 years, and eight (13 %) for more than 21 years. Fifty-five (92 %) observers super vised surgical trainees in the operating room. Most ob-servers (77 %) treated more than 20 distal radius fractures per year. One (2 %) observer was a general orthopedic surgeon, 22 (37 %) were orthopedic trauma surgeons, 10 (17 %) were shoulder and elbow surgeons, 22 (37 %) were hand and wrist surgeons, and five (8 %) were other surgeons (Table 3.1).

Inter-observer reliability

Presence of a fracture in the coronal planeIn the X-ray group, a total of 364 coronal fractures were found, while 372 coronal frac-tures of the distal radius were found in the CT-group. The inter-observer variation for the presence of an articular fracture of the lunate facet in the coronal plane was fair both with use of radiographs alone and with use of radiographs and 2DCT (κR 0.29, SE 0.05 and κCT 0.24, SE 0.07; p 0.55).

Instability of the coronal plane fractureIn the X-ray group, 228 of the 364 coronal fractures were found unstable. In the CT group, 232 of the 372 coronal fractures of the distal radius were found unstable. Inter-observer agreement on instability of the coronal split fracture was fair for both radiographs and radiographs with 2DCT (κR 0.29, SE 0.02, and κCT 0.32, SE 0.02,p 0.28).

Observer demographics

With respect to the presence of a coronal fracture line in the lunate facet, the only sig-nificant finding with respect to observer demographics was that shoulder and elbow specialists had better agreement with 2DCT than radiographs (Table 3.2). With respect of instability of the lunate facet fracture, the only significant findings were that hand and wrist surgeons had a significant greater agreement than other specialists, and ex-perienced surgeons had greater agreement than less experienced surgeons (Table 3.3).

Table 3.2. Fracture line in the coronal plate: differences in inter-observer variability

Specialty Radiographs 2-Dimensional CT P value

N Categorial k SE N Categorial k SE

Orthopedic Traumatology 11 Fair 0.36 0.07 11 Slight 0.15 0.10 0.12

Shoulder and elbow 7 Slight 0.15 0.13 3 Substantial 0.67 0.22 0.04*

Hand 10 Fair 0.32 0.11 12 Slight 0.20 0.13 0.52

Other 3 Fair 0.38 0.16 2 Poor 0.19 0.42 0.21

N = Number of Observers, SE = standard error*P<0.05 (significant)

Chapter 3

50

DISCUSSION

Inter-observer agreement regarding the diagnosis of a coronal articular fracture of the lunate facet of the distal radius and instability of that fracture when present are both fair. Additional 2DCT did not improve agreement over radiographs alone on average. These findings were quite consistent across training, experience, and region. The only posi-tive findings were that observers that treat more than 10 distal radius fractures a year and specialized hand and wrist surgeons seem more consistent in defining a fracture as unstable, but diagnosis of stability was a secondary study question and the significant findings must be interpreted in the context of multiple testing.

We are not aware of any prior studies of the reliability of diagnosing coronal plane fractures of the lunate facet, but three prior studies address diagnosis of articular fracture lines with CT compared to radiographs. In one study of suspected distal radius fractures, CT scans demonstrated a fracture in 22 patients, only 19 of which were visible on radiographs (16 intra-articular).4 In another study of 18 intra-articular distal radius fractures, CT scans demonstrated seven fractures involving the DRUJ, five involving the radial styloid that were not seen on radiographs.9 The third study identified an articular fracture involving the DRUJ on 13 of 20 CT scans, but only seven of 20 radiographs.10 None of these studies had a reference standard for true fracture such as intraoperative visualization of the articular surface.

This study should be interpreted in light of its potential shortcomings: (1) We did not provide coronal plane images; (2) the observers may have interpreted the ques-tion differently when faced with a multifragmented fracture, with some only applying that diagnosis to a single coronal split fracture; (3) the observers were not provided any clinical data (e.g., age, sex, mechanism); (4) the quality of the radiographs was limited to what had been obtained at the time of injury, which reflects usual practice, but not what might be achieved with specific protocols; (5) there was a spectrum bias by select-ing cases to represent the known variety of injuries, with the result that less common complex fractures were over represented compared to the more common minimally or

Table 3.3. Fracture instability: differences in inter-observer variability

Fractures per year

N Categorial K1 SE1 N Categorial K2 SE2 P-value

10 or less vs 11 or more 5 Slight 0.16 0.06 26 Fair 0.31 0.02 0.01

10 or less vs 20 or more 5 Slight 0.16 0.06 24 Fair 0.32 0.02 0.01

Specialty

Trauma vs. Hand 11 Fair 0.25 0.03 10 Fair 0.36 0.04 0.04

Hand vs. non Hand 10 Fair 0.36 0.04 21 Fair 0.27 0.02 004

N=Number of observers, SE = standard error

51


3

slightly displaced fractures; (6) we asked numerous secondary study questions, all of which should be regarded as hypothesis generating and not as robust as the primary study question; (7) we don’t know how carefully each observer studied the radiographs and scans; and (8) having only 16 patients may limit the external validity of the findings. However, according to statisticians, the power of a reliability study is determined by the total number of observations, which given the number of observers in this study was quite high.

This study does not support the use of CT scans for the diagnosis of coronal articular fracture lines in the lunate facet of the distal radius, at least in terms of reliability. This study did not evaluate the diagnostic performance characteristics of CT or radiographs for coronal plane fractures. We believe that future studies should attempt to clarify the definition of these fracture lines and further address the role of experience and training in observer variation.

REFERENCES

1. Bowers WF. The distal radioulnar joint. In: Hucherson DC, editor. editor: Operative hand surgery. 3rd ed. New York: Churchill Livingstone; 1993. p. 973–1019.

2. Cohen J. A coefficient of agreement for nominal scales. Edoc Psychol Meas. 1960; 20: 37–46. 3. Hucherson DC. The Darrach operation for lower radioulnar derangement. Am J Surg. 1941; 53:

237–41. 4. Johnston GHF, Friedman L, Kriegler JC. Computerized tomographic evaluation of acute distal

radial fractures. J Hand Surg.1992; 17A: 737–44. 5. Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biom. 1977; 33:

159–74. 6. Melone Jr CP. Articular fractures of the distal radius. Orthop Clin N Am. 1984; 15: 217–36. 7. Müller ME, Allgöwer M, Schneider R, et al. Manual of internal fiation. 3rd ed. New York: Springer;

1991. 8. Posner KL, Sampson PD, Caplan RA, et al. Measuring interrater reliability among multiple raters:

an example of methods for nominal data. Stat Med. 1990; 9: 1103–15. 9. Pruitt DL, Gilula LA, Manske PR, et al. Computed tomography scanning with image reconstruction

in evaluation of distal radius fractures. J Hand Surg. 1994; 19A: 720–7. 10. Rozental TD, Bozentka DJ, Katz MA, et al. Evaluation of the sigmoid notch with computed tomog-

raphy following intra- articular distal radius fracture. J Hand Surg [Am]. 2001; 26A: 244–51. 11. Siegel S, Castellan NJ. Nonparametric statistics for the behavioral sciences. 2nd ed. New York:

McGraw-Hill; 1988.

12345678910111213

Chapter 4Computed tomography for the detection of distal radioulnar joint instability: Normal variation and

reliability of four CT scoring systems in 46 patients

Chapter 4

54

M.M.E. Wijffels, W. Stomp, P. Krijnen, M. Reijnierse, I.B. Schipper

submitted

ABSTRACT

Objectives: The diagnosis of distal radioulnar joint (DRUJ) instability is clinically chal-lenging. Computed Tomography (CT) may aid in the diagnosis, however the reliability and normal variations of existing CT scoring have not yet been established in detail. The aim of this study was to evaluate inter- and intraobserver agreement of CT scoring methods for determination of DRUJ translation in both posttraumatic and uninjured wrists. Secondly, we aimed to define the normal ranges for these scoring methods.Subjects and Method: Patients with a conservatively treated, unilateral distal radius frac-ture were invited to participate. CT scans of both wrists were evaluated independently, by two readers using the Radioulnar line method, the Subluxation ratio method, the Epicenter method and the Radioulnar ratio method. The inter- and intraobserver agree-ment were assessed and normal values were determined using the data of uninjured wrists.Results: Ninety-two wrist-CTs of 38 females and 8 males (mean age: 56.5 years, SD: 17.0, mean follow-up 4.2 years, SD: 0.5) were evaluated. Interobserver agreement was best for the Epicenter method (ICC=0.73, 95% confidence interval [CI] 0.65-0.79) and was better for injured wrists. Intraobserver agreement was almost perfect for the Radioulnar line method (ICC=0.82, 95% CI 0.77-0.87). Each scoring method showed a wide range for normal DRUJ translation.Conclusion: The Epicenter method seems to be the most reliable method for scoring DRUJ translation, using CT-scan of the injured wrist. Considerable variation exists in the range of normal values.

55

Computed tomography for the detection of distal radioulnar joint instability

4

INTRODUCTION

Distal radius fractures comprise one in six fractures that are diagnosed at the emergency department.1-3 The incidence of distal radial ulnar joint (DRUJ) instability after distal ra-dius fractures varies from 0 to 35% one year after trauma.4-7 The complex biodynamics of the wrist show that during pronosupination the radioulnar fibers collaborate in prevent-ing the ulna from luxating out of the sigmoid notch.8 In extreme positions, additional stabilizing structures, such as the joint capsule, support the DRUJ from dislocation.9 Posttraumatic changes may influence these stabilizing structures; complete triangular fibrocartilage complex (TFCC) tears or ulnar styloid fractures have been found to relate to DRUJ instability.4,7

Diagnosing DRUJ instability remains a challenge since the generally accepted avail-able clinical test, i.e. the stress-test, suffers from subjectivity and lack of validity.10 Radiographs can be of additional value, although obtaining true lateral views is difficult and radiographs do not depict the dynamic process of DRUJ movement.4,11-14 Computed tomography (CT) of both wrists in pronation and supination may overcome these limita-tions.13,15,16

Several methods for determining DRUJ luxation by means of a wrist-CT have been proposed.11,14,17-19 To our knowledge only one paper has evaluated the reliability of CT-scans in determining DRUJ instability.21 Park et al, tested four scoring methods on 45 volunteers and unilateral wrists without a history of trauma, with three observers. They favored the Subluxation ratio and reported substantial variation in normal values in 70˚ of pro- and supination. In previously injured wrists, reliability of DRU translation measurement may differ from what Park et al found, due to posttraumatic anatomical changes. However, little is known about the reproducibility of the CT scorings systems in previously injured wrists. Furthermore, findings may differ when the DRUJ stabiliz-ing structures are stressed at maximal forearm rotation. The aim of our study was to determine the most reliable method in terms of inter- and intraobserver agreement, to compare reliability of measurements in injured, with those in uninjured wrists and to determine normal ranges of radioulnar translation for these scoring methods in our population.

SUBJECTS AND mETHODS

Patients

All patients, over 18 years of age at trauma, treated conservatively for a distal radius fracture between May 2008 and February 2010 in our hospital were eligible for inclusion in this study. Patients were excluded if they 1) were unwilling or unable to provide in-

Chapter 4

56

formed consent, or 2) had systemic diseases such as Rheumatoid Arthritis and Systemic Lupus Erythematosus (SLE), or 3) had contralateral wrist injury. Eligible patients received an invitation letter for a study visit. After informed consent, the presence of pain in forearm rotation against resistance was documented using a visual analogue scale and radiological DRUJ translation was assessed using CT. The institutional medical ethics review board approved the study.

The fractures were classified based on the baseline radiograph by one reader (MW) according to the Comprehensive Classification of Fractures in type A, B and C fractures.20 No control radiographs were performed at final follow-up; fracture healing was deter-mined on the CT with reformatting.

Computed tomography

CT scan (Aquilion One or 64, Toshiba, Tokyo, Japan) was performed in prone position with both arms above the head and extended elbows, both in maximal pronation and maximal supination (tube voltage 120 KV, tube current 70 mA, rotation time 0.5 s, slice thickness 0.5 mm, slice increment 0.4 mm). The scanned range was from 5 cm proximal of the radiocarpal joint to 1 cm distal of the metacarpal heads. Postprocessing was performed by trained radiology employees and included 2 mm coronal and sagittal re-formats, as well as 2 mm axial reformats perpendicular to the axis of the styloid process for each wrist separately.

Radiological assessment of DRUJ instability

DRUJ translation was quantified using four methods; the Radioulnar line method11,18, the Subluxation ratio method, the Epicenter method19 and the Radioulnar ratio method.17 All methods measure radioulnar translation by evaluating ulnar position relative to the radius resulting in a ratio. For training purposes the amount of DRUJ translation was evaluated using the four mentioned scoring methods in 10 CT-scans of wrists not involved in this study, by two observers (MW and WS) and prior to the definitive mea-surements.

The axial reformatted CT image of each wrist showing the largest area of the sigmoid notch, including Lister tubercle and the ulnar head were selected by each individual observer for measurement of ulnar translation in both pro- and supination. All slides were independently assessed in random order by both observers, who were blinded for patient and clinical characteristics. At a minimum of three weeks after the first series of reviews, one observer (MW) assessed all CT slides for a second time in random order, for the determination of intraobserver reliability.

Quantification of the ulnar position relative to the radius of both the injured and uninjured wrist was done in four ways:

57


4

1. According to the Radioulnar line method11,18 two lines are drawn; one through the volar ulnar and radial borders of the radius (Figure 4.1, line a) and a second through the dorsal ulnar and radial borders of the radius (Figure 4.1, line b). The maximum distance of the ulnar head outside these two lines is measured, perpendicular to line a; line CD. A fourth line connecting the two edges of the sigmoid notch is drawn, which defines the length of the sigmoid notch (length AB). The ratio of CD to AB is calculated. Volar dislocation of the ulnar head relative to the radius is considered negative, dorsal dislocation as positive. If the ulnar head is situated between line A and B the value is recorded as 0.

2. According to the Subluxation ratio method21 a line connecting the two edges of the sigmoid notch (point A and B) is drawn, which defines the length of the sigmoid notch (Figure 4.2, length AB). Two lines (line a and line b) are drawn perpendicular to this line, and cross the edges of the sigmoid notch. The maximum distance of the ulnar head outside line a or b is measured perpendicular on this line (distance CD). The ratio between the length of extra-articular ulnar head and the sigmoid notch length is calculated (CD/ AB). Volar dislocation of the ulnar head relative to the radius is considered negative, dorsal dislocation as positive.

3. According to the Epicenter method19 a line connecting the two edges of the sigmoid notch is drawn (Figure 4.3, line AB), which defines the length of the sigmoid notch. Using two circles the center of the ulnar head and ulnar styloid process is marked; point a and b respectively. The center of rotation of the DRUJ is marked by point D; the crossing of a perpendicular to line AB through point c, halfway the line connect-ing point a and b. The distance between point D and the midpoint of the sigmoid notch, point C, is measured. The ratio between distance CD and AB is calculated. Volar dislocation of the ulnar head relative to the radius is considered negative, dorsal dislocation as positive.

4. According to the Radioulnar ratio method17 a line (Figure 4.4, line AB) connecting the two edges of the sigmoid notch is drawn, which defines the length of the sigmoid notch. A second line (line C) is drawn, perpendicular to the first one and through the center of the ulnar head (point C), defined by a circle facing the articular surface. The ratio between the distance from the cross point of the two lines (point D) to the volar edge of the sigmoid notch (length AD) and the length of sigmoid notch (length AB) is calculated.

Statistical Analysis

To evaluate the reliability (inter- and intraobserver agreement) of DRUJ translation measurements on CT, Intraclass Correlation Coefficients (ICC) with their 95% confidence interval (CI) were calculated using the two-way random model for absolute agreement. The ICCs were interpreted according to Landis and Koch who proposed that values 0.01

Chapter 4

58

to 0.20 indicate slight agreement; 0.21 to 0.40, fair agreement; 0.41 to 0.60, moderate agreement; 0.61 to 0.80, substantial agreement; and 0.81 to 1, almost perfect agree-ment.22,23 Statistical difference in agreement was defined by absence of overlap in 95% confidence intervals of the ICCs.

The number of observations needed was calculated to ensure significant agreement if the agreement was at least 0.4, with an alpha of 0.05, and a beta of 0.2. The minimal sample size of wrist CT scans to be reviewed was found to be 87.24

Figure 4.1. The Radioulnar line method = CD/AB: the amount of ulnar head volar or dorsal from the ulnar line is measured (CD). The ratio of this length to the length of the sigmoid notch (AB) is calcu-lated.

Figure 4.2. The Subluxation ratio method = CD/AB. The length of the sigmoid notch is defined by length AB. The distance of the ulnar head outside line a or b is measured perpendicular on this line (distance CD). The ratio between the length of extra-articular ulnar head and the sigmoid notch length is calculated (CD/ AB).

Figure 4.3. The Epicenter method = CD/AB. The centre of rotation (point D) is defined by the center of the ulnar head and ulnar styloid process (point a and b respectively). The distance between point D and the midpoint of the sigmoid notch, point C, is measured.

Figure 4.4. The radioulnar ratio method = AD/AB. The length of the sigmoid notch is measured (length AB). A line perpendicular to line AB and the center of the ulnar head is defines point D.

59


4

The normal range of ulnar translation for each method was based on CT-scans of the uninjured wrists and defined as the mean value ±2SD for both pro- and supination. To correct for a potential observation learning curve, mean values of CT measurements were based on the first observation of both observers.

RESULTS

One hundred-fifty-eight patients met the inclusion criteria and were invited for a study visit. Thirty-six patients were lost to follow-up and 73 were unwilling to participate. No patients were excluded based on a systemic disease or contralateral wrist injury. Three of the remaining 49 participants had an incomplete CT-scan, leaving 46 participants with 92 wrist-CTs (pro- and supination) for analysis. The study group consisted of 38 females and 8 men with a mean age of 56.5 years (SD17.0, range 18-87) at trauma. Their mean posttraumatic follow-up at the time of CT-scan performance was 4.2 years (SD 0.5, range 3.3-5.0). Twelve patients suffered from pain in the injured wrist with a VAS-score ranging from 5 to 80 points (0 indicating no pain, 100 indication worst pain ever experienced). In one patient this was not recorded. Another patient reported pain in the contralat-eral wrist. The fractures were classified according to the Comprehensive Classification of Fractures as follows: 22 type A, 4 type B and 20 type C fractures.20 All distal radius fractures were consolidated at final follow-up.

The highest interobserver and intraobserver agreement, independent of position or posttraumatic state of the wrist, was found for the Epicenter Method (ICC=0.73 95% CI 0.65-0.79 and ICC=0.82, 95% CI 0.77-0.87, respectively) as presented in Table 4.1. When wrist position was taken into account interobserver agreement remained best for the Epicenter method in both pronation (ICC=0.47, 95% CI 0.16-0.67) and supination (ICC=0.72, 95% CI: 0.58-0.81). Accounting for wrist position, intraobserver agreement was best for the Radioulnar line method in both pronation (ICC=0.67, 95% CI 0.53-0.77) and supination (ICC=0.82, 95% CI: 0.74-0.88). All ICCs were higher for supination mea-

Table 4.1. Intraclass Correlation Coefficients (ICC) with 95% Confidence Interval (CI) for interobserver and intraobserver agreement on four scoring methods for measuring DRUJ instability on 184 CT-scans of the wrist.

method Interobserver agreement (ICC, 95% CI) Intraobserver agreement (ICC, 95% CI)

Radioulnar line 0.53 (0.22-0.71) 0.75 (0.68-0.81)

Subluxation ratio 0.51 (0.20-0.69) 0.64 (0.54-0.72)

Epicenter 0.73 (0.65-0.79) 0.82 (0.77-0.87)

Radioulnar ratio 0.68 (0.55-0.76) 0.76 (0.70-0.82)

Chapter 4

60

surements as compared to the corresponding pronation measurements. (Further data not shown).

The ICCs for interobserver agreement of all four methods, separately for injured and uninjured wrists, are presented in Table 4.2. Agreement on measurements in supination with the Epicenter method for the injured wrists was almost perfect (ICC=0.82, 95% CI 0.69-0.89), and was significantly better than that for the uninjured wrists.

The ICCs for intraobserver agreement of all four methods, separately for injured and uninjured wrists, are presented in Table 4.3. Best and almost perfect agreement was found for the Radioulnar line method on supination CT imaging of the injured wrist (ICC=0.92, 95% CI 0.86-0.95), which was significantly better compared to the uninjured wrist.

In Table 4.4 the mean ratios of ulnar translation for all four scoring methods for injured and uninjured wrists in pro- and supination are presented. The normal range of ulnar translation ratios differed from 30% in the Epicenter method in supination to 59% in the Subluxation Ratio in pronation.

Table 4.2. Intraclass Correlation Coefficients (ICC) with 95% Confidence Interval (CI) for interobserver agreement on four scoring methods for measuring DRUJ instability in pro- and supination on CT.

Method PronationICC (95% CI)

SupinationICC (95% CI)

Injured(n=46)

Non-injured(n=46)

Injured(n=46)

Non-injured(n=46)

Radioulnar line 0.16 (−0.07-0.40) 0.37 (0.02-0.62) 0.68 (0.32-0.84) 0.33 (0.05-0.56)

Subluxation ratio 0.20 (−0.06-0.45) 0.28 (−0.02-0.53) 0.62 (0.29-0.80) 0.22 (−0.04-0.46)

Epicenter 0.54 (0.19-0.75) 0.42 (0.08-0.66) 0.82 (0.69-0.89) 0.47 (0.18-0.68)

Radioulnar ratio 0.52 (−0.01-0.78) 0.30 (−0.10-0.62) 0.60 (0.37-0.76) 0.35 (0.07-0.58)

Table 4.3. Intraclass Correlation Coefficients (ICC) with 95% Confidence Interval (CI) for intraobserver agreement on four scoring methods for measuring DRUJ instability in pro- and supination on CT.

Method PronationICC (95% CI)

SupinationICC (95% CI)

Injured(n=46)

Non-injured(n=46)

Injured(n=46)

Non-injured(n=46)

Radioulnar line 0.54 (0.28-0.72) 0.74 (0.58-0.85) 0.92 (0.86-0.95) 0.62 (0.40-0.77)

Subluxation ratio 0.23 (−0.03-0.47) 0.62 (0.40-0.77) 0.90 (0.83-0.94) 0.49 (0.24-0.68)

Epicenter 0.55 (0.31-0.72) 0.60 (0.38-0.76) 0.84 (0.73-0.91) 0.45 (0.19-0.66)

Radioulnar ratio 0.61 (0.39-0.77) 0.65 (0.45-0.79) 0.63 (0.42-0.78) 0.64 (0.44-0.79)

61


4DISCUSSION

In this study, the best interobserver agreement of four scoring methods, for determi-nation of DRUJ translation by means of CT-scan, was established using the Epicenter Method. This method also showed good corresponding intraobserver agreement values and agreement was better for injured wrists compared to uninjured wrists. Based on these data the Epicenter Method seems the most reliable method to evaluate distal radioulnar translation on CT-scans.

Our findings are in contrast with the data published earlier by Park et al.21 They found a substantial to almost perfect interobserver agreement for the Radioulnar line method in supination and pronation respectively, for uninjured wrists. A plausible explanation for the difference between the findings of Park and ours is hard to find. In both studies, the CT protocol used is identical and wrist positioning and image selection is performed concordantly. The inclusion of posttraumatic wrists in our study has no negative effect on the reproducibility of the measurements.

Normal ranges

During pronation of the wrist, the unstabilized ulnar head tends to move dorsal relative to the radius. Ulnar translation is therefore one of the indicators of insufficiency of the DRUJ stabilizers; i.e. DRUJ instability. The ratios calculated using the four methods were translated into a percentage representing the amount of ulnar head dislocation outside the sigmoid notch. Using the Epicenter method, which had the best interobserver agreement, normal values of ulnar translation varied from 35% volar dislocation to 6% dorsal dislocation in pronation and from 11% volar dislocation to 19% dorsal dislocation in supination. Mino described, using the Radioulnar line method, the position of the ulnar head within the lines through the dorsal and volar border in every rotational posi-tion.11,18 This resulted in a narrow window for normal values, which is smaller then what was found based on our data. Using Mino’s criteria would easily lead to high numbers

Table 4.4. Mean ratio values with standard deviation (SD) of radioulnar deviation measured with the four scoring methods on CT for the injured and non-injured wrists, and normal values based on the non-injured wrist, in pro- and supination.

Method Injured wristMean (SD)

Non-injured wristMean (SD)

Normal range

Pronation Supination Pronation Supination Pronation Supination

Radioulnar line −0.05 (0.11) −0.22 (0.18) 0.14 (0.15) −0.15 (0.12) −0.15-0.43 −0.39-0.08

Subluxation ratio −0.02 (0.11) −0.20 (0.17) 0.05 (0.15) −0.17 (0.11) −0.25-0.34 −0.39-0.04

Epicenter −0.17 (0.09) −0.01 (0.13) −0.15 (0.10) 0.04 (0.08) −0.35-0.06 −0.11-0.19

Radioulnar ratio 0.56 (0.11) 0.29 (0.16) 0.58 (0.09) 0.33 (0.12) 0.39-0.77 0.09-0.58

Chapter 4

62

of patients with uninjured wrist function who are considered to have an abnormal DRUJ and DRUJ instability (false-positive findings). On the other hand Park et al.21 reported normal values in uninjured wrists varying from 27% volar to 35% dorsal dislocation; a wider range then what we found. Based on Parks wide normal range one may judge an actual unstable DRUJ as normal on CT scan, leading to a false negative outcome. These findings correspond with the results of Kim and colleagues25, who found a poor correla-tion between CT-findings and clinical DRUJ assessment. We therefore recommend to interpret normal values with caution when determining DRUJ instability on CT-scans. To avoid false positive and negative findings, we suggest, in accordance to Nakamura and colleagues,14 to compare the healthy and the injured wrist of a patient expected to have DRUJ instability. The uninjured wrist will reflect the normal laxity of the DRUJ in both pro- and supination. However, no studies on this theory for any of the four scoring methods have been published.14 For patients with injuries of both wrists, normal values as presented by Park, Mino and our data, are the best available reference.

One of the limitations of this study is that only the reliability of CT-scans for determi-nation of clinical DRUJ instability could be evaluated. Since no reliable and objective test is available for diagnosing DRUJ instability, we were not able to evaluate the validity of CT-scans for determination of clinical DRUJ instability. Nevertheless, these results are valuable given the lack of reliable data on the evaluation of methods for diagnosing radiological DRUJ instability using CT in injured wrists.

CONCLUSION

Measurements for DRUJ instability on CT in pro- and supination can be reliably per-formed in both normal and posttraumatic wrists. The Epicenter method is the method of choice. There is large normal variation in DRUJ movement. Scanning of both wrists prevents the radiological overdiagnosis of instability.

REFERENCES

1. Hollingworth R, Morris J. The importance of the ulnar side of the wrist in fractures of the distal end of the radius. Injury. 1976; 7: 263-6

2. Lindau TR, Aspenberg P, Arner M et al. Fractures of the distal forearm in young adults. An epide-miologic description of 341 patients. Acta Orthop Scand. 1999; 70: 124-8

3. Sammer DM, Shah HM, Shauver MJ et al. The effect of ulnar styloid fractures on patient-related outcomes after volar locking plating of distal radius fractures. J Hand Surg Am. 2009; 34: 1595-602

4. Lindau T, Adlercreutz C, Aspenberg P. Peripheral Tears of the triangular fibrocartilage complex cause distal radioulnar joint instability after distal radial fractures. J Hand Surg Am. 2000; 25; 464-8

63


4

5. Lindau T, Hagberg L, Adkrcreutz C et al. Distal radioulnar instability is an independent worsening factor in distal radial fractures. Clin Orthop Relat Res. 2000; 376: 229-35.

6. Wijffels M, Ring D. The influence of non-union of the ulnar styloid on pain, wrist function and instability after distal radius fracture. J Hand Microsurg. 2011; 3: 11-4

7. Krӓmer S, Meyer H, O’Loughlin PF et al. The incidence of ulnocarpal complaints after distal radial fracture in the relation to the fracture of the ulnar styloid. J Hand Surg Eur Vol. 2013; 38: 710-17

8. Hagert CG. Distal radius fracture and the distal radioulnar joint – anatomical consideratioins. Handchir Mikrochir Plast Chir 1994; 26: 22-6.

9. Af Ekenstam F, Hagert CG. Anatomical studies on the geometry and stability of the distal radio ulnar joint. Scand J Plast Reconstr Surg. 1985; 19: 17-25.

10. Jupiter JB. Commentary: The effect of ulnar styloid fractures on patient-rated outcomes after volar locking plating of distal radius fractures. J Hand Surg Am. 2009; 34: 1603-4.

11. Mino DE, Palmer AK, Levinsohn EM. The role of radiography and computerized tomography in the diagnosis of subluxation and dislocation of the distal radioulnar joint. J Hand Surg Am. 1983; 8: 23-31.

12. Nakamura R, Horii E, Imaeda T et al. Distal radioulnar joint subluxation and dislocation diagnosed by standard roentgenography. Skeletal Radiol. 1995; 24: 91-4.

13. Pirela-Cruz MA, Goll SR, Klug M et al. Stress computed tomography analysis of the distal radioul-nar joint: a diagnostic tool for determining translational motion. J Hand Surg Am. 1991; 16: 75-82.

14. Nakamura R, Horii E, Imaeda T et al. Criteria for diagnosing distal radioulnar joint subluxation by computed tomography. Skeletal Radiol. 1996; 25: 649-53.

15. King GJ, McMurrey RY, Ruberstein JD et al. Computerized tomography of the distal radioulnar joint: correlation with ligamentous pathology in a cadaveric model. J Hand Surg Am. 1986; 11: 711-17.

16. Metz VM, Gilula LA. Imaging techniques for distal radius fractures and related injuries. Orthop Clin North Am. 1993; 24: 217-28

17. Lo IK, MacDermid JC, Bennet JD et al. The radioulnar ratio: a new method of quantifying distal radioulnar joint subluxaton. J Hand Surg Am. 2001; 26: 236-43.

18. Mino DE, Palmer AK, Levinsohn EM. Radiography and computerized tomography in the diagnosis of incongruity of the distal radio-ulnar joint. A prospective study. J Bone Joint Surg Am. 1985; 67: 247-52.

19. Wechsler RJ, Wehbe MA, Rifkin MD et al. Computed tomography diagnosis of distal radioulnar subluxation. Skeletal Radiol. 1987; 16: 1-5

20. Müller ME, Allgöwer M, Schneider R et al. Manual of internal fixation. 3rd ed. New York: Springer, 1991.

21. Park MJ, Kim JP. Reliability and normal values of various computed tomography methods for quantifying distal radioulnar joint translation. J Bone Joint Surg Am. 2008; 90: 145-53.

22. Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics. 1977; 33: 159-74

23. Posner KL, Sampson PD, Caplan RA et al. Measuring interrater reliability among multiple raters: an example of methods for nominal data. Stat Med. 1990; 9: 1103-15

24. Walter SD, Eliasziw M, Donner A. Sample size and optimal designs for reliability studies. Stat Med. 1998; 17: 101-10

25. Kim JP, Park MJ. Assessment of Distal Radioulnar Joint Instability After Distal Radius Fracture: Comparison of Computed Tomography and Clinical Examination Results. J Hand Surg Am. 2008; 33: 1486-92.

12345678910111213

Part IIIAcute treatment

12345678910111213

Chapter 5Impact of ulnar styloid fractures in nonoperatively

treated distal radius fractures

Chapter 5

68

M.K. van Valburg, M.M.E. Wijffels, P. Krijnen, I.B. Schipper

Eur J Trauma Emerg Surg 2013;39(2):151-57

ABSTRACT

Purpose: The effect of an ulnar styloid fracture (USF) on the stability of nonoperatively treated distal radius fractures (DRF) is unknown. The aim of this study was to evaluate the influence of USFs on the dislocation of DRFs treated by closed reduction.Methods: Standardized radiographs of 100 nonoperatively treated DRFs were evaluated. DRFs with an USF were compared to DRFs without an USF with respect to dorsal tilt, radial inclination, and ulnar variance.Results: We evaluated the radiographs of 100 DRFs in 99 consecutive patients, of whom 84 were women. An accompanying USF was present in 58 wrists, of which 49 were displaced. On the trauma radiograph, the USF group showed significantly more overall dislocation. After closed reduction, fracture position improved, and no significant dif-ferences in dislocation were observed between groups. After a mean of 42 days, radial inclination significantly decreased if an USF was present. When USF displacement was taken into account, significantly more ulnar variance occurred in the displaced USF group on the trauma and follow-up radiograph compared to the nondisplaced USF group and no-USF group.Conclusions: The results of this study show that presence of an dislocated USF in patients with a DRF is associated with a worse position directly after trauma, and with recurrence of radial shortening after adequate reduction. These results warrant early radiologic follow-up in patients with reduced combined DRFs and USFs in order to evaluate the redislocation of the distal radius. Early detection of redislocation in these combined fractures may induce early surgical intervention.

69

Impact of ulnar styloid fractures in nonoperatively treated distal radius fractures

5

INTRODUCTION

One in six patients who present with a fracture at the emergency department has a distal radius fracture (DRF).1–3 Of those patients, 44–65 % also have an ulnar styloid fracture (USF).4–7 Since the triangular fibrocartilage complex (TFCC) inserts on the base of the ulnar styloid3, 8–10, distal radioulnar (DRU) joint instability may result when an USF is present, due to TFCC disruption.11–16

In only minimally dislocated DRFs, nonoperative treatment leads to a satisfactory anatomical end result17, since the functional outcome of the DRF depends on restora-tion of the anatomy.18–20 Several radiographic parameters may have prognostic value for the outcome of DRF treatment.21, 22 Radial inclination could be useful for assessing the reduction adequacy of DRFs.22, 23. Ulnar variance and dorsal tilt have a negative influence on functional outcome20, 24 and may alter the DRU joint.18–20

In operatively treated DRFs, the presence of an USF does not affect the outcome with respect to wrist function and DRU joint stability.25–28 In nonoperatively treated patients with DRFs, Oskarsson et al.6 suggested that a worse outcome resulted from a DRF in the presence of an USF after radial consolidation. Since corrections of acute dislocated fractures are less complex and produce better results than secondary osteotomies, we were interested in the relation between the presence of an USF and the amount of radial fracture dislocation in the acute phase and after short-term follow-up. Therefore, the aim of our study was to evaluate the influence of an USF on the extent of dislocation of a nonoperatively treated DRF, after adequate closed reduction. Our hypothesis was that nonoperatively treated DRFs with an USF show more dislocation on radiography directly after trauma and after short-term follow-up compared to DRFs without an accompany-ing USF.

PATIENTS AND mETHODS

For this retrospective cohort study, all patients who had been diagnosed with a DRF that had been treated nonoperatively between May 2008 and February 2010 at a level-one trauma center, were selected from the hospital database. Demographic and clinical data were obtained from the database. Patients who met at least one of the following criteria were excluded from the study: (1) pathologic fracture; (2) previous wrist injury; (3) DRF treated without closed reduction; (4) missing or incorrect radiographs; and (5) follow-up of less than two weeks. Also, 35 patients with a DRF that underwent surgery after a secondary dislocation during the study period (of which 24 had an accompanying USF) were excluded from further analyses.

Chapter 5

70

Treatment consisted of closed reduction of the fracture, in the acute setting, and im-mobilization by a plaster of Paris or fiberglass cast for six weeks. Standard follow-up was performed at 5–7 days, 2 and 4–6 weeks after trauma. The radiographs that had been taken directly after trauma, directly after closed reduction, and at the last follow-up, were analyzed.

Radiographic evaluation

On the standardized anteroposterior and lateral wrist radiographs, three radiographic parameters (dorsal tilt, radial inclination, and ulnar variance) were evaluated by one re-searcher (MvV) using Image Toolbox in Mirador V5 (iSoft Group PLC, Banbury, UK). Dorsal or palmar tilt was determined on the lateral view as the angle between a line connecting the volar and dorsal margins of the articular surface and a line perpendicular to the central axis of the radius29 (Figure 5.1a). Radial inclination and ulnar variance were both determined on the anteroposterior view. Radial inclination was determined as the angle between a line perpendicular to the long axis of the radius and a line joining the radial and ulnar margins of the articular surface23 (Figure 5.1b). Ulnar variance was determined as the distance, perpendicular to the central axis of the radius, between the cortical rim of the ulnar seat and the most proximal point on the distal articular surface of the radius30 (Figure 5.1c). Positive ulnar variance indicated radial shortening; negative ulnar variance indicated radial lengthening. Normal values of dorsal tilt, radial inclination, and ulnar variance as compared to the ulna have previously been reported as 9° (range 2°–15°)26, 24° (range 19°–29°)23, and +0.9 mm (range −4.2 to 2.3 mm)23 respectively.

Fracture type was classified according to the AO classification and patients were as-signed to either the USF group or the no-USF group based on the trauma radiographs. Furthermore, displacement and the level of the USF were taken into account. Displace-ment of the USF was defined as a distance between the two fracture parts of 2 mm or more on the anteroposterior trauma radiograph.26 USF level was either an ulnar styloid base fracture (if more than 75 % of the ulnar styloid was involved in the fracture frag-ment) or a tip fracture.3

Effect of treatment

The effect of fracture reduction on each radiographic parameter (dorsal tilt, radial inclination, and ulnar variance) was defined as the difference between that parameter measured on the reduction radiograph and measured on the trauma radiograph prior to reduction (reduction effect = Xreduction - Xtrauma). The short-term effect of treat-ment was determined as the difference between the parameter measured on the last available follow-up radiograph and measured on the reduction radiograph (short-term effect = Xlast - Xreduction). For example, a short-term treatment effect for dorsal tilt of Xlast - Xreduction = 5 − 12 = −7 implied a 7° change in dorsal tilt.

71


5


The independent samples t test and one way analysis of variance were used for group comparisons of continuous data. Categorical data were analyzed and compared with the χ2 test. Statistical significance was assumed for P<0.05.

a

Figure 5.1.a Dorsal tilt was determined as the angle between a line connecting the volar and dorsal margins of the articular surface and a line perpendicular to the cen-tral axis of the radius.b Radial inclination was determined on the anterio-posterior view as the angle between a line perpen-dicular to the long axis of the radius and a line joining the radial and ulnar margins of the articular surface.c Ulnar variance was determined on the anteriopos-terior view as the distance, perpendicular to the cen-tral axis of the radius, between the cortical rim of the ulnar seat and the most proximal point on the distal articular surface of the radius. Positive ulnar variance indicated radialshortening; negative ulnar variance indicated radial lengthening

b c

Chapter 5

72

RESULTS

During the study period, 282 patients with 283 DRFs were treated nonoperatively in our hospital. Of these patients, 183 met one or more exclusion criteria. The remaining 99 patients with 100 DRFs were subject to analysis in this study (Figure 5.2).

Patient characteristics

The study group included 15 men (15 %) and 84 women (85 %) with a mean age of 64.1 (SD 17.9) years. One woman suffered from a DRF in both wrists. Fifty DRFs (50 %) were located in the left wrist. Accompanying USFs were present in 58 wrists (58 %), of which 49 (84 %) were displaced and 49 (84 %) were base fractures. The USF and no-USF groups were comparable regarding age, gender, and fracture type (Table 5.1).

Presence of USF

Dorsal tilt, radial inclination, and ulnar variance after trauma and at the last follow-up were compared between the USF and no-USF group (Table 5.2). On the trauma radio-

Figure 5.2. Flowchart of patients that had been diagnosed with distal radius fractures between May 2008 and February 2010 at a level-one trauma center

73


5

graph, the USF group showed on average 3.8° less radial inclination and 1.9 mm more ulnar variance than the no-USF group (P = 0.03 and 0.04, respectively). The USF group had 4.7° more dorsal tilt on average than the no-USF group, but this difference was not statistically significant (P = 0.15). There were no statistically significant radiographic differences on the reduction radiograph between the USF and no-USF group. The final follow-up radiographs in the USF group showed on average 2.3° less radial inclination than those in the no-USF group (P = 0.03), and ulnar variance tended to be more positive in the USF group (mean difference 1.2 mm, P = 0.07), despite adequate reduction ac-cording to the reduction radiograph. Shortly after closed reduction, ulnar variance was on average 1.7 mm more improved in the USF group than in the no-USF group (P = 0.03). In the longer term, the relapse in ulnar variance was more extensive in the USF group, although this difference was not statistically significant (Table 5.3).

USF displacement and level

To assess the effect of a displaced USF on the radiographic parameters, the USF group was subdivided into USFs with or without displacement and compared to the no-USF group (Table 5.4). Comparison of these three groups showed significantly more ulnar variance in the displaced USF group on the trauma and follow-up radiograph compared to the nondisplaced USF group and the no-USF group. The effect of the USF level on the radiographic parameters was evaluated in Table 5.5. Comparison of radiographic parameters between the ulnar styloid base fracture group and the ulnar styloid tip fracture group showed no significant differences.

Table 5.1. Characteristics of 99 patients with 100 DRFs who underwent closed reduction, categorized ac-cording to the presence or absence of a USF

Characteristic USFN = 58

No USFN = 42

P-value

mean age (SD) in years 64,3 (18,7) 63,9 (16,9) 0,92

Gender, n (%) Male 10(17) 5 (12) 0.46

Female 48 (83) 37 (88)

AO-classification, n (%) 23A 26 (45) 19 (45) 0.43

23B 2 (3) 4 (10)

23C 30 (52) 19 (45)

mean follow-up (SD) in days 42.1 (29.0) 42.6 (44.4) 0.95

Results are presented as mean (SD)

Chapter 5

74

Tabl

e 5.

2. R

adio

grap

hic

eval

uatio

n of

99

patie

nts

with

100

DRF

s w

ho u

nder

wen

t clo

sed

redu

ctio

n

Radi

ogra

phic

par

amet

ers

Trau

ma

radi

ogra

phRe

duct

ion

radi

ogra

phLa

st fo

llow

-up

radi

ogra

ph

USF

N =

58

No

USF

N =

42

P-va

lue

USF

N =

58

No

USF

N =

42

P-va

lue

USF

N =

58

No

USF

N =

42

P-va

lue

Dor

sal t

ilt (°

)118

,7 (1

6,7)

14,0

(14,

9)0,

15−2

,3 (8

,2)

−2,7

(6,4

)0,

777

2,0

(9,9

)0,

7 (1

0,7)

0,52

Radi

al in

clin

atio

n (°

)10

,0 (9

,0)

13,8

(7,1

)0,

0320

,1 (4

,9)

23,2

(15,

2)0,

145

14,3

(6,2

)16

,6 (4

,2)

0,03

Uln

ar v

aria

nce

(mm

)22,

7 (4

,8)

0,8

(3,9

)0,

04−0

,9 (3

,2)

−1,1

(3,0

)0,

671

2,0

(3,4

)−0

,8 (3

,1)

0,07

Bold

num

bers

indi

cate

sta

tistic

al s

igni

fican

t out

com

es o

f the

test

s. Ra

diog

raph

s w

ere

take

n af

ter t

raum

a, a

fter

redu

ctio

n an

d at

last

follo

w-u

p. R

esul

ts a

re c

ateg

oriz

ed

acco

rdin

g to

the

pres

ence

or a

bsen

ce o

f USF

. Res

ults

are

pre

sent

ed a

s th

e m

ean

(SD

)1 N

egat

ive

valu

es in

dica

te p

alm

ar ti

lt, p

ositi

ve v

alue

s in

dica

te d

orsa

l tilt

.2 P

ositi

ve v

alue

s in

dica

te ra

dial

sho

rten

ing,

neg

ativ

e va

lues

indi

cate

radi

al le

ngth

enin

g.

Tabl

e 5.

3. R

educ

tion

and

shor

t-te

rm e

ffect

s of

redu

ctio

n on

radi

ogra

phic

par

amet

ers

in p

atie

nts

with

a D

RF, c

ateg

oriz

ed a

ccor

ding

to th

e pr

esen

ce o

r abs

ence

of U

SF

Radi

ogra

phic

par

amet

ers

Shor

t-te

rm re

duct

ion

effec

t = X

redu

ctio

n − X

trau

ma

Long

-ter

m re

duct

ion

effec

t1 = X

last

− X

redu

ctio

n

USF

gro

up N

= 5

8N

o U

SF g

roup

N =

42

P-va

lue

USF

gro

up N

= 5

8N

o U

SF g

roup

N =

42

P-va

lue

Dor

sal t

ilt (°

)21

,0 (1

7,2)

16,7

(15,

1)0,

20−4

,3 (1

1,4)

−3,4

(10,

5)0,

69

Radi

al in

clin

atio

n (°

)10

,1 (8

,6)

9,5

(14,

8)0,

79−5

,8 (6

,0)

−6,6

(14,

8)0,

71

Uln

ar v

aria

nce

(mm

)3,

6 (4

,4)

1,9

(3,0

)0,

03−2

,9 (2

,7)

−2,0

(2,3

)0,

06

Bold

num

bers

indi

cate

sta

tistic

al s

igni

fican

t out

com

es o

f the

test

s. Re

sults

are

pre

sent

ed a

s th

e m

ean

diffe

renc

e (S

D)

1 Neg

ativ

e va

lues

indi

cate

that

the

posi

tion

of th

e fr

actu

re w

as b

ette

r on

the

redu

ctio

n ra

diog

raph

than

on

the

last

follo

w-u

p ra

diog

raph

.

75


5

Tabl

e 5.

4. R

adio

grap

hic

eval

uatio

n of

99

patie

nts

with

100

DRF

s w

ho u

nder

wen

t clo

sed

redu

ctio

n

Radi

ogra

phic

pa

ram

eter

sTr

aum

a ra

diog

raph

Redu

ctio

n ra

diog

raph

Last

follo

w-u

p ra

diog

raph

USF

gr

oup

Dis

plac

edN

= 4

9

USF

gro

upN

on-

disp

lace

dN

= 9

No

USF

gr

oup

N =

42

P-va

lue

USF

gr

oup

Dis

plac

edN

= 4

9

USF

gro

upN

on-

disp

lace

dN

= 9

No

USF

gr

oup

N =

42

P-va

lue

USF

gr

oup

Dis

plac

edN

= 4

9

USF

gro

upN

on-

disp

lace

dN

= 9

No

USF

gr

oup

N =

42

P-va

lue

Dor

sal t

ilt (°

)118

,7 (1

5,2)

18,7

(16,

0)14

,0 (1

4,9)

0,36

−3,3

(7,7

)3,

0 (9

,3)

−2,7

(6,4

)0,

062,

0 (9

,9)

1,8

(10,

5)0,

7 (1

0,7)

0,82

Radi

al in

clin

atio

n (°

)9,

8 (9

,4)

11,2

(7,0

)13

,8 (7

,1)

0,08

20,2

(5,2

)19

,7 (3

,4)

23,2

(15,

2)0,

3514

,0 (6

,5)

15,6

(4,2

)16

,6 (4

,2)

0,08

Uln

ar v

aria

nce

(mm

)23,

2 (4

,6)

0,2

(5,3

)0,

8 (3

,9)

0,02

−0,6

(3,2

)−2

,5 (2

,6)

−1,1

(3,0

)0,

202,

6 (3

,2)

−0,9

(3,2

)0,

8 (3

,1)

0,00

bold

num

bers

indi

cate

sta

tistic

al s

igni

fican

t out

com

es o

f the

test

sRa

diog

raph

s w

ere

take

n af

ter t

raum

a, a

fter

redu

ctio

n, a

nd a

t la

st fo

llow

-up.

Res

ults

are

cat

egor

ized

acc

ordi

ng to

the

pre

senc

e of

dis

loca

ted

or n

ondi

sloc

ated

USF

or

abse

nce

of U

SF. R

esul

ts a

re p

rese

nted

as

mea

n (S

D)

1 Neg

ativ

e va

lues

indi

cate

pal

mar

tilt,

pos

itive

val

ues

indi

cate

dor

sal t

ilt.

2 Pos

itive

val

ues

indi

cate

radi

al s

hort

enin

g, n

egat

ive

valu

es in

dica

te ra

dial

leng

then

ing.

Tab

le 5

.5. R

adio

grap

hic

eval

uatio

n of

99

patie

nts

with

100

DRF

s w

ho u

nder

wen

t clo

sed

redu

ctio

n

Radi

ogra

phic

pa

ram

eter

sTr

aum

a ra

diog

raph

Redu

ctio

n ra

diog

raph

Last

follo

w-u

p ra

diog

raph

USF

bas

e N

=49

USF

tip

N=9

p-va

lue

USF

bas

e N

=49

USF

tip

N=9

p-va

lue

USF

bas

e N

=49

USF

tip

N=9

p-va

lue

Dor

sal t

ilt (°

)120

.1 (1

5.2)

10.8

(22.

7)0.

12−2

.1 (8

.3)

−3.4

(8.2

)0.

662.

3 (1

0)0.

2 (9

.9)

0.56

Radi

al in

clin

atio

n (°

)9.

8 (8

.6)

11.0

(11.

4)0.

7220

.0 (5

.2)

20.6

(3.2

)0.

7313

.8 (6

.2)

16.8

(5.5

)0.

18

Uln

ar v

aria

nce

(mm

)2−2

.7 (4

.7)

−2.6

(5.2

)0.

971.

1 (3

.1)

−0.2

(3.3

)0.

27−1

.8 (3

.4)

−3.1

(3.7

)0.

29

Radi

ogra

phs

wer

e ta

ken

afte

r tra

uma,

aft

er re

duct

ion,

and

at l

ast f

ollo

w-u

p. R

esul

ts a

re c

ateg

oriz

ed a

ccor

ding

to th

e fr

actu

re le

vel o

f USF

. Res

ults

are

pre

sent

ed a

s th

e m

ean

(SD

)1 N

egat

ive

valu

es in

dica

te p

alm

ar ti

lt, p

ositi

ve v

alue

s in

dica

te d

orsa

l tilt

2 Pos

itive

val

ues

indi

cate

radi

al s

hort

enin

g, n

egat

ive

valu

es in

dica

te ra

dial

leng

then

ing

Chapter 5

76

DISCUSSION

To our knowledge, this is the first report in the literature on the potential influence of an USF on early fracture stability in nonoperatively treated DRFs. The results of this study show that the presence of a dislocated USF in patients with a DRF is associated with a worse position directly after trauma and with recurrence of radial shortening after adequate reduction.

Positive ulnar variance is a significant negative influence on functional outcome after DRF.31 If ulnar variance cannot be corrected adequately using closed fracture reduction, this may present an indication for operative reduction and fixation. However, in many patients, the positive ulnar variance will occur over time. In this study, ulnar variance oc-curred more frequently during follow-up in patients with an accompanying USF treated by closed reduction. Therefore, a fractured ulnar styloid can be regarded as a risk factor for positive ulnar variance, indicating the need for frequent follow-up radiographs in the two first weeks after closed reduction. The USF itself does not need operative fixation since, in operatively treated DRFs, an USF in itself does not affect outcome in terms of strength and function.3,25,26, 28 Like all retrospective analyses, this study has limitations. Radiological measurements were performed in retrospect by one researcher who was not blinded for the presence of an USF, patients had to be excluded because of incom-plete data, and some clinical data were lacking. In daily practice it is not common to take radiographs of the uninjured wrist, so a comparison with the uninjured contralateral distal radius in order to evaluate radial length was not possible in this study population. Another limitation of the study is that patients who had been primarily treated nonop-eratively but were operated on during follow-up were not included in this study. It is expected, however, that the radiologic deviations after initial follow-up (before surgery) in those patients would be even larger than those seen in the present study group. The inclusion of these patients in the study would therefore have strengthened our findings. Because only one researcher performed all measurements, the interobserver variability could not be calculated. For the same reason, the measurements were not influenced by interobserver variability, and were therefore comparable in the analysis of all subgroups. Furthermore, comminution of the dorsal cortex was not taken into account, since it cannot be measured objectively on conventional radiographs. If dorsal comminution is present, the corrected position of the DRF after reduction is not mechanically sup-ported. In conclusion, the presence of a dislocated USF in patients with a DRF is associ-ated with a worse position directly after trauma and with recurrence of radial shortening after adequate reduction. The ulnar styloid significantly contributes to the stability of the distal radial fragment. Due to the decreased fracture stability in combined DRFs and USFs, the clinical implication of this finding is that the presence of a USF in patients with a DRF warrants early radiologic control after closed reduction. Redislocation may

77


5

be considered an indication for early surgical fixation in order to prevent malunion and subsequent functional impairment.

REFERENCES

1. Hollingsworth R, Morris J. The importance of the ulnar side of the wrist in fractures of the distal end of the radius. Injury.1976; 7(4): 263–6.

2. Lindau TR, Aspenberg P, Arner M et al. Fractures of the distal forearm in young adults. An epide-miologic description of 341 patients. Acta Orthop Scand. 1999; 70 (2): 124–8.

3. Sammer DM, Shah HM, Shauver MJ et al. The effect of ulnar styloid fractures on patient-rated out-comes after volar locking plating of distal radius fractures. J Hand Surg Am. 2009; 34(9): 1595–602.

4. Frykman G. Fracture of the distal radius including sequelae—shoulder-hand-finger syndrome, disturbance in the distal radioulnar joint and impairment of nerve function. A clinical and experi-mental study. Acta Orthop Scand. 1967; 108(Suppl): 7–153

5. Lindau T, Arner M, Hagberg L. Intraarticular lesions in distal fractures of the radius in young adults. A descriptive arthroscopic study in 50 patients. J Hand Surg Br. 1997; 22(5): 638–43.

6. Oskarsson GV, Aaser P, Hjall A. Do we underestimate the predictive value of the ulnar styloid affection in Colles fractures? Arch Orthop Trauma Surg. 1997; 116(6–7): 341–4.

7. Richards RS, Bennett JD, Roth JH et al. Arthroscopic diagnosis of intra-articular soft tissue injuries associated with distal radial fractures. J Hand Surg Am. 1997; 22(5): 772–6.

8. Kleinman WB. Stability of the distal radioulna joint: biomechanics, pathophysiology, physical diagnosis, and restoration of function what we have learned in 25 years. J Hand Surg Am. 2007; 32(7): 1086–106.

9. Mikic ZD. Detailed anatomy of the articular disc of the distal radioulnar joint. Clin Orthop Relat Res. 1989; 245: 123–32.

10. Palmer AK, Werner FW. The triangular fibrocartilage complex of the wrist—anatomy and function. J Hand Surg Am. 1981; 6(2): 153–62.

11. Adams BD, Samani JE, Holley KA. Triangular fibrocartilage injury: a laboratory model. J Hand Surg Am. 1996; 21(2): 189–93.

12. Hauck RM, Skahen J III, Palmer AK. Classification and treatment of ulnar styloid non-union. J Hand Surg Am. 1996; 21(3): 418–22.

13. Haugstvedt JR, Berger RA, Nakamura T et al. Relative contributions of the ulnar attachments of the triangular fibrocartilage complex to the dynamic stability of the distal radioulnar joint. J Hand Surg Am. 2006; 31(3): 445–51.

14. Kikuchi Y, Nakamura T. Avulsion fracture at the fovea of the ulna. A report of two cases. J Hand Surg Br. 1998; 23: 176–8.

15. May MM, Lawton JN, Blazar PE. Ulnar styloid fractures associated with distal radius fractures: inci-dence and implications for distal radioulnar joint instability. J Hand Surg Am. 2002; 27(6): 965–71.

16. Zimmermann R, Rudisch A, Fritz D, Gschwentner M, Arora R. MR imaging for the evaluation of accompanying injuries in cases of distal forearm fractures in children and adolescents. Handchir Mikrochir Plast Chir. 2007; 39(1): 60–7.

17. Lafontaine M, Hardy D, Delince P. Stability assessment of distal radius fractures. Injury. 1989; 20(4): 208–10.

Chapter 5

78

18. Geissler WB, Fernandez DL, Lamey DM. Distal radioulnar joint injuries associated with fractures of the distal radius. Clin Orthop Relat Res. 1996; 327: 135–46.

19. Palmer AK, Werner FW. Biomechanics of the distal radioulnar joint. Clin Orthop Relat Res. 1984; 187: 26–35.

20. Stoffelen D, De Smet SL, Broos P. The importance of the distal radioulnar joint in distal radial fractures. J Hand Surg Br. 1998; 23 (4): 507–11.

21. Porter M, Stockley I. Fractures of the distal radius. Intermediate and end results in relation to radiologic parameters. Clin Orthop Relat Res. 1987; 220: 241–52.

22. van der Linden W, Ericson R. Colles’ fracture. How should its displacement be measured and how should it be immobilized? J Bone Jt Surg Am. 1981; 63(8): 1285–8.

23. Schuind FA, Linscheid RL, An KN et al. A normal data base of posteroanterior roentgenographic measurements of the wrist. J Bone Jt Surg Am. 1992; 74(9): 1418–29.

24. Adams BD. Effects of radial deformity on distal radioulnar joint mechanics. J Hand Surg Am. 1993; 18(3): 492–8.

25. Buijze GA, Ring D. Clinical impact of united versus nonunited fractures of the proximal half of the ulnar styloid following volar plate fixation of the distal radius. J Hand Surg Am. 2010; 35(2): 223–7.

26. Kim JK, Koh YD, Do NH. Should an ulnar styloid fracture be fixed following volar plate fixation of a distal radial fracture? J Bone Jt Surg Am. 2010; 92(1): 1–6.

27. Souer JS, Ring D, Matschke S et al. Effect of an unrepaired fracture of the ulnar styloid base on outcome after plate-and-screw fixation of a distal radial fracture. J Bone Jt Surg Am. 2009; 91(4): 830–8.

28. Zenke Y, Sakai A, Oshige T et al. The effect of an associated ulnar styloid fracture on the outcome after fixation of a fracture of the distal radius. J Bone Jt Surg Br.2009; 91(1): 102–7.

29. Gartland JJ, Werley CW. Evaluation of healed Colles’ fractures. J Bone Jt Surg Am. 1951; 33-A(4): 895–907.

30. Gelberman RH, Salamon PB, Jurist JM et al. Ulnar variance in Kienbock’s disease. J Bone Jt Surg Am. 1975; 57(5): 674–6.

31. Knirk JL, Jupiter JB. Intra-articular fractures of the distal end of the radius in young adults. J Bone Jt Surg Am. 1986; 68(5): 647–59.

12345678910111213

Chapter 6The influence of non-union of the ulnar styloid

on pain, wrist function and instability after distal radius fracture

Chapter 6

82

M.M.E. Wijffels, D. Ring

Journal of Hand and Microsurgery. 2011 Jun;3(1):11-4.

ABSTRACT

The influence of non-union on the outcome of distal radius fractures is debated. We tested the null hypothesis that there is no difference in pain, wrist function, or instability between patients with union or non-union of an ulnar styloid base fracture after opera-tive treatment of a fracture of the distal radius. Eighteen adults with an ulnar styloid base non-union were compared to 16 patients with union of an ulnar styloid base fracture with a mean post-operative follow-up of 30 months. None of the patients had distal radioulnar joint instability, there were no significant differences in pain, complications, or function, and patients with non-union had significantly greater grip strength. Ulnar styloid non-union is not associated with pain, instability, or diminished function after fracture of the distal radius.

83

The influence of non-union of the ulnar styloid on pain, wrist function and instability after distal radius fracture

6

INTRODUCTION

Substantially displaced fractures of the distal radius disrupt the distal radioulnar liga-ments, either by directly tearing them or by disrupting the origin of the ligaments via fracture of the base of the ulnar styloid. The long-standing concern about base of ulnar styloid fractures2, 6, 7, 9, 10,12, 14–16 has been questioned by four recent studies that found such fractures did not affect outcome after volar plate fixation.4, 8,13,17 Both Kim et al. and Souer et al. focused on the presence of an ulnar styloid base fracture more then non-union of this fracture. No adverse influence on outcome of distal radius fractures was found if a fractured ulnar styloid was present.

There has been concern about non-union of the ulnar styloid as a potential source of ongoing ulnar-sided wrist pain after fracture of the distal radius1,6; however, recent stud-ies have also questioned this concept.4,17 Buijze et al. presented the shortterm results of volar plating of distal radius fractures analyzing the influence of an accompanying ulnar styloid base non-union. Zenke et al. reported results of outcome of volar plating of distal radius fractures with special attention for the non-union of the accompanying ulnar styloid fracture. Both studies showed no difference in patients with a non-united ulnar styloid base fracture.

Another concern is that a base-of-styloid fracture would increase the risk of problems with distal radioulnar joint (DRUJ) instability in distal radius fractures.6,18 Neither Zenke and colleagues nor Buijze and colleagues encountered DRUJ instability, but this was not consistently formally tested by Buijze and colleagues.

Our aim was to look at the same question using a different data set in order to further test the null hypothesis that there is no difference in outcome between patients with union and non-union of the ulnar styloid base fracture with focus on function, pain, distal radioulnar joint stability, grip-strength and outcome of health assessment ques-tionnaires.

mATERIAL AND mETHODS

Participants

A single surgeon operated on 120 adult patients with an unstable fracture of the distal radius with a fracture at the base of ulnar styloid between 2000 and 2007. For the pur-poses of this investigation, a fracture of the ulnar styloid base was defined as a fracture at least 50% of the total height on the posteroanterior radiograph of the wrist. In nine patients the ulnar styloid base fracture was more than 2-millimeters radially translated after anatomical fixation of the radius and was therefore reduced and secured with a

Chapter 6

84

tension band wire construct. No specific treatment was provided to the remaining 111 patients.

Using a protocol approved by our Human Research Committee, we reviewed medical records and invited patients with less then 6 months follow-up to return for a free follow-up. We excluded 77 patients with fewer than 6 months follow-up that either could not be contacted (46 patients) or declined to return (31 patients). Nineteen patients had at least 6 months follow-up in the medical record and 15 returned for a research specific evaluation.

Non-union of the ulnar styloid was defined as a visible fracture line on conventional posteroanterior radiographs at least 6 months after trauma. Sixteen patients were diag-nosed with union and 18 with non-union of the ulnar styloid base fracture.

Union of the ulnar styloid base

Among patients with union of the ulnar styloid base fracture there were five men and 11 women with a mean age of 57 years (range 41 to 75 years). The fractures were classified according to the Comprehensive Classification of Fractures as follows: 2 A2 fracture, 1 A3, 1 B1, 3C1, 2C2, and 7C3 fractures.11 The left hand was involved in 11 patients (three dominant), the right in 5 (four dominant). The operative technique included volar locked plating in nine patients, percutaneous pinning in 1, external fixation in 4, combined volar and dorsal plating in 2.

Non-union of the ulnar styloid base

Among patients with non-union of the ulnar styloid base fracture there were seven men and 11 women with a mean age of 54 years (range 25 to 81). The fractures were classified according to the Comprehensive Classification of Fractures as follows: 2 A2 fracture, 2 A3, 1 B2, 8C1, 4C2 and 1C3 fractures.11 The left hand was involved in 14 patients (two dominant), the right in 4 (three dominant). The operative technique included volar plat-ing in 16 patients and percutaneous pinning in 1, combined volar and dorsal plating in 1. No significant differences were found in baseline characteristics between the two groups.

Evaluation

Pain and function were evaluated using the Mayo modified wrist score3 and the Gart-land and Werley score.5 Fifteen patients returned for a research-specific evaluation that was done by an investigator not involved in the care of the patients and consisted of measurement of range of motion and grip-strength. Instability in the DRUJ was evalu-ated in these 15 patients (7 with union and 8 with non-union of the ulnar styloid) that returned for a research specific visit, by comparing anterioposterior translation of the distal ulna under stress of the injured wrist to the uninjured wrist, after manual fixation

85


6

of the distal radius, with elbow in 90° flexion and wrist in neutral position. Grip-strength was measured by the investigator as the average of three attempts using a handheld dynamometer (Preston; Jackson, MI) with the arm at the side, the elbow at 90° flexion, and the forearm and wrist in neutral position. Grip strength and range of motion of the involved arm was compared to the opposite side and the percentage (involved/non-involved arm) was calculated. Range of motion was measured using a goniometer. All patient files were reviewed for complications and subsequent surgeries.


Pre- and postoperative characteristics and outcome scores of both groups were com-pared using independent sample t- test for continuous data. Categorical data were com-pared between groups using Independent Samples test with two outcomes or Pearson’s Chi-square with more than two outcomes. P-values of less then 0.05 were considered statistically significant.

RESULTS

Patients with non-union of the ulnar styloid were evaluated an average of 31 months (range: 6 to 74 months) after injury and patients with union of the ulnar styloid after 30 months (range 7 to 73 months). (p = 0.8)

Complications and subsequent surgeries

No post-operative infections, tendon ruptures, loss of reduction, or implant failures were encountered. Seven patients had a second surgery for plate removal: 5 with union and two with non-union of the ulnar styloid (p =0.147).

Pain

Among patients with union of the ulnar styloid, 11 patients reported no pain, three mild discomfort, and two patients moderate pain. Among patients with non-union of the ulnar styloid 11 patients reported no pain, six mild pain and one patient moderate pain.

Range of motion

In patients with union of the ulnar styloid base fracture the flexion and extension av-eraged 55° (range, 20–90°) and 57° (range, 30–75°) respectively. These averages were both 81% comparing the injured to the uninjured arm. Radial deviation averaged 21° (range 0–56°) which is 86% compared to the uninjured arm. Ulnar deviation averaged 40° (range 20–60°) which is 74% compared to the uninjured arm. The average prona-tion and supination measured 84° (range, 20–95°) and 78° (range, 20–90°) respectively.

Chapter 6

86

Compared to the uninjured arm these averages were 95% for pronation and 93% for supination. The average grip strength was 80% of the uninjured arm.

In patients with non-union of the ulnar styloid base fracture the flexion and extension averaged 57° (range,30–80°) and 64° (range, 40–94°) respectively. These averages were 84% and 87% respectively comparing the injured to the uninjured arm. Radial devia-tion averaged 29° (range 10–66°) which is 100% compared to the uninjured arm. Ulnar deviation averaged 39° (range 14–60°) which is 87% compared to the uninjured arm. The average pronation and supination measured 84° (range, 35–95°) and 88° (range, 60–90°) respectively. Compared to the uninjured arm these averages were 97% for pronation and 98% for supination. The average grip strength was 94% of the uninjured arm. The Gartland and Werley averaged 4 (range 0–12). Categorical ratings were excellent out-come in ten patients, good in five patients, and fair in two patients. One patient failed to fill out questionnaires properly.

Functional rating scales

Among patients with union of the ulnar styloid the Mayo-score averaged 78 (range 60–95). The categorical ratings were excellent outcome in two patients, good in five patients, and fair in nine patients. The Gartland and Werley averaged 5 (range 0–21). Categorical ratings were excellent outcome in eight patients, good in seven patients and poor in one patient. Among patients with non-union of the ulnar styloid the Mayo-score averaged 81 (range 60–100). The categorical ratings were excellent outcome in three patients, good in eight patients, and fair in one patient.


There were no significant differences between cohorts in terms of flexion, extension, pronation, supination, ulnar deviation, radial deviation, Mayo-score (p = 0.45) or Gart-

Table 6.1. Comparison of patients with union and non-union of the ulnar styloid

Union (degrees) (% of non-injured side)

Non-union (degrees) (% of non-injured side)

p-value

Flexion 55 (81) 57 (84) 0.67

Extension 57 (81) 64 (87) 0.39

Radial deviation 21 (86) 29 (100) 0.26

Ulnar deviation 40 (74) 39 (87) 0.19

Pronation 84 (95) 84 (97) 0.80

Supination 78 (93) 88 (98) 0.35

Grip * 80 94 0.05

* % of non-injured side

87


6

land and Werley score (p =0.06). Grip-strength (p = 0.05) was found significantly better in patients with non-union of the ulnar styloid (Table 6.1).

DRUJ instability

None of the 15 patients who visited our hospital for this research specific evaluation was diagnosed with DRUJ instability during physical examination.

DISCUSSION

Distal radius fractures are often accompanied by an ulnar styloid base fracture and there is no consensus regarding optimal treatment of this part of the injury. In this study non-union of an ulnar styloid base fracture did not affect outcome of operatively treated distal radius fractures in this study, with the exception of grip-strength, which was found to be significantly better in patients with an ulnar styloid non-union. The higher grip strength may be spurious given the relatively small number of patients and the absence of other plausible explanations.

Our findings are consistent with the findings of Zenke et al and Buijze et al.4,17 They found no relationship between ulnar sided wrist pain and union of the ulnar styloid. In our study we were only able to evaluate pain in the wrist, without specification of loca-tion, nevertheless we did not find any difference in pain between patients with union of the ulnar styloid compared to those with non-union.

Given that non-union of the ulnar styloid is common, and ulnar sided pain persisting for upwards of 1 year after fracture of the distal radius is also common (in patients with and without an ulnar styloid fracture), it is unclear what relationship, if any, the non-union has to persistent wrist pain.6,17 Hauck and colleagues6 classified symptomatic non-union of ulnar styloid fractures dependent on stability of DRUJ. Resection of the fragment in 15 patients resulted in a good outcome if DRUJ-stability was never disturbed or was restored during operation. All three patients treated with open reposition and internal fixation of the fractured ulnar styloid experienced pain relief. Speculative sources for pain include injury to the TFCC attachments, irritation from the non-united fragment and impingement of the extensor carpi ulnaris tendon sheath by a fibrous non-union, but most patients with displaced fractures have TFCC or ulnar styloid injury and few have pain. Better experiments are needed to determine the correlation between persis-tent wrist pain and ulnar styloid non-union.

The shortcomings of this study include the small number of patients, loss of many patients, reliance on the medical record in many patients, and relatively short-term fol-low- up. On the other hand, this data is worth considering given that so few publications have focused on non-union of ulnar styloid base fractures.

Chapter 6

88

Non-union of an ulnar styloid base fracture is not clearly associated with pain or wrist dysfunction after operative treatment of a distal radius fracture. Patients and surgeons should be mindful that ulnar side wrist pain can persist for upwards of a year after fracture of the distal radius—with or without an ulnar styloid fracture. The idea that a non-union of the ulnar styloid is a good surgical target for improving comfort and function may lead to unneeded operative intervention. So we conclude from our study that non-union of ulnar styloid base has little influence on the outcome of distal radius fractures. We urge caution in electing operative treatment of ununited ulnar styloid fractures until better scientific support for treatment of pain associated with an ulnar styloid non-union is available.

REFERENCES

1. Abid A, Accadbled F, Kany J et al (2008) Ulnar styloid fracture in children: a retrospective study of 46 cases. J Pediatr Orthop B 17: 15–19

2. af Ekenstam F, Jakobsson OP, Wadin K (1989) Repair of the triangular ligament in Colles’ fracture: no effect in a prospective randomized study. Acta Orthop Scand 60: 393–396

3. Amadio PC, Berquist TH, Smith DK et al (1989) Scaphoid malunion. J Hand Surg Am 14(4): 679–687 4. Buijze G, Ring D (2010) Clinical impact of united versus nonunited fractures of the proximal half of

the ulnar styloid following volar plate fixation of the distal radius. J Hand Surg Am 35(2): 223–227 5. Gartland JJ Jr, Werley CW (1981) Evaluation of healed Colles’ fractures. J Bone Joint Surg Am 33:

895–907 6. Hauck RM, Skahen J III, Palmer AK (1996) Classification and treatment of ulnar styloid non-union.

J Hand Surg 21A: 418–422 7. Kaukonen JP, Karahuarju EO, Porras M et al (1988) Functional recovery after fractures of the distal

forearm. Analysis of radiographic and other factors affecting the outcome. Ann Chir Gynaecol 77: 27–31

8. Kim JK, Koh YD, Do NH (2010) Should an ulnar styloid fracture be fixed following volar plate fixa-tion of a distal radial fracture? J Bone Joint Surg Am 92(1): 1–6

9. Lindau T, Arner M, Hagberg I (1997) Intraarticular lesions in distal fractures of the radius in young adults. A descriptive arthroscopic study in 50 patients. J. Hand Surg Br 5: 638–643

10. Melone CP, Nathan R (1992) Traumatic disruption of the triangular fibrocartilage complex. Clin Orthop 275: 65–73

11. Müller ME, Allgöwer M, Schneider R et al (1991) Manual of internal fixation, 3rd edn. Springer, New York

12. Oskarsson GV, Asser P, Hjall A (1997) Do we underestimate the predictive value of the ulnar styloid affection in Colles fractures? Arch Orthop Trauma Surg 116: 341–344

13. Souer JS, Ring D, Matschke S et al (2009) Effect of an unrepaired fracture of the ulnar styloid base on outcome after plate-and-screw fixation of a distal radial fracture. J Bone Joint Surg Am 91 (4): 830–838

14. Stoffelen D, de Smet L, Broos P (1998) The importance of the distal radioulnar joint in distal radial fractures. J Hand Surg 23B: 507–511

15. Tsukazaki T, Iwasaki K (1993) Ulnar wrist pain after Colles’ fracture. Acta Orthop Scand 64: 462–464

89


6

16. Villar RN, Marsh D, Rushton N et al (1987) Three years after Colles’ fracture: a prospective review. J Bone Joint Surg 69B: 635–638

17. Zenke Y, Sakai A, Oshige T et al (2009) The effect of an associated ulnar styloid fracture on the outcome after fixation of a fractures of the distal radius. J Bone Joint Surg Br 91 (1): 102–107

18. Zimmermann R, Rudisch A, Fritz D et al (2007) MR imaging for the evaluation of accompanying injuries in cases of distal forearm fractures in children and adolescents [in German]. Handchir Mikrochir Plast Chir 39(1): 60–67

12345678910111213

Chapter 7Ulnar styloid process non-union and outcome

in patients with a distal radius fracture: A meta-analysis of comparative clinical trials

Chapter 7

92

M.M.E. Wijffels, J. Keizer, G.A. Buijze, Y. Zenke, P. Krijnen, N.W.L. Schep, I.B. Schipper

Injury. 2014;45(12):1889-95

ABSTRACT

Purpose: There is no consensus on the relation between ulnar styloid process non-union and outcome in patients with distal radius fractures. The aim of this study was to analyze whether patient-reported outcome is influenced by the non-union of the accompanying ulnar styloid fracture in distal radius fracture patients.Methods: A meta-analysis of published studies comparing outcomes after distal radius fractures with a united versus a non-united ulnar styloid process was performed. In addi-tion, if provided by the authors, the raw data of these studies were pooled and analyzed as one study. The outcome measures of the analyses included patient-reported outcome, functional outcome, grip-strength, pain, and distal radioulnar joint (DRUJ) instability.Results: Data from six comparative studies were included, concerning 365 patients with a distal radius fracture. One hundred and thirty-five patients with an ulnar styloid union were compared with 230 patients with a non-union of the ulnar styloid. No significant differences were found between groups regarding any outcome measure.Conclusion: Based on this meta-analysis, there is no relation between the non-union of the ulnar styloid process and function in patients with a distal radius fracture.

93

Ulnar styloid process non-union and outcome in patients with a distal radius fracture

7

INTRODUCTION

One in six patients who present with a fracture at the emergency department has a distal radius fracture (DRF).1–3 Of those patients, 44–65% also have an ulnar styloid process (USP) fracture.4–7 Displacement of DRFs may result in disruption of the distal radioulnar ligaments, either by direct ligamentous tear or by avulsion of the origin of the ligaments, that is, a fracture at the ulnar fovea or the ulnar styloid.5,6,8–17 Ulnar styloid avulsion may result in distal radioulnar joint (DRUJ) instability due to triangular fibrocar-tilage complex (TFCC) disruption, the principal stabilizer of the DRUJ.9,18–22 Non-union of the USP fracture has been proposed as a potential source of ongoing ulnar-sided wrist pain and DRUJ instability.9,22,23 Mentzel and colleagues reported a better residual function if the USP fracture unites.24 Others found that non-union of the ulnar styloid did not affect functional outcome or pain following volar plate fixation of a DRF.25–30 To date, the relation between USP non-union and outcome in patients with DRFs is unclear, due to the conflicting results and small sample sizes of the published studies. Therefore, a meta-analysis was performed to provide the best available evidence. The primary aim of this meta-analysis was to compare functional outcome between patients with and without the union of an ulnar styloid and a healed DRF.


The meta-analysis was performed according to the Preferred Reporting Items for Sys-tematic Reviews and Meta-Analysis (PRISMA) statement.31

Types of studies and participants

All studies comparing DRF patients, with and without union of the USP fracture, were assessed for inclusion in the present study.

Inclusion and exclusion criteria

Inclusion criteria were (1) English or German language, (2) reporting patient-reported outcome measure (PROM), pain, function, and/or DRUJ instability, (3) operatively or non-operatively treated patients, and (4) follow-up of 6 months or more. Exclusion criteria were (1) case series, (2) not available as full text article, (3) no reports on outcome data required for analyses, (4) no reports on 95% confidence intervals or standard deviations for outcome data, (5) the required data for this meta-analysis could not be derived from the published data, nor from the raw data, and (6) multi-trauma patients.

Chapter 7

94

Outcome measures

The primary outcome of this meta-analysis was patient-reported outcome based on questionnaires. Secondary outcome measures were range of motion, grip strength, pain, and clinical DRUJ instability. Furthermore, data extracted from the studies included patient characteristics, study design, sample size, type of radius fracture, length and completeness of follow-up, and type of treatment of the DRF.

Search methods for identification of studies

The systematic search was performed by a professional librarian and a member of our research team (M.M.E.W.) without any limit in publication date in PubMed, EMBASE, Web of Science, COCHRANE, CINAHL, Academic Search Premier, ScienceDirect, Springer, Wiley Blackwell, LWW, HighWire, and Informahealth. The search was conducted on October 22, 2013. The search strategy combined various terms and synonyms for ulnar styloid fractures and DRFs. The complete search strategy is shown in the Appendix.

Selection of studies

After removing duplicates, two surgical trainees (M.M.E.W. and J.K.) screened the title and abstract of all studies identified in the initial search, using the inclusion and exclusion criteria. If no abstract was available, the full text was assessed for eligibility. Nonrelevant studies were excluded. Full text copies of the remaining studies were independently assessed according to the predefined inclusion and exclusion criteria. In addition, the reference lists of selected articles were screened for relevant studies not identified in the search, using the above criteria. Disagreements were resolved by means of discussion and arbitration by an experienced trauma surgeon (I.S.).

Assessment of methodological quality

The methodological quality of the selected studies was assessed using the quality as-sessment tool derived from the Grading of Recommendation Assessment, Development, and Evaluation (GRADE) Working Group.32 The overall quality of evidence was based on study design, study quality, consistency, and directness. To evaluate the limitations in methodological quality, loss to follow-up and consistency of treatment strategy were scored. Disagreements were resolved by means of discussion, with arbitration by an independent trauma surgeon with a master in clinical epidemiology (N.S).

Data collection

The two surgical trainees (M.M.E.W. and J.K.) independently extracted data from all eli-gible studies. The corresponding authors of included papers were contacted by e-mail and requested to provide the raw data.

95


7

Analysis of raw data

The available raw data were assembled in one database and analysed as if they were results from one study. Scores on patient-reported outcome questionnaires, range of motion and grip strength (expressed as percentage of that of the uninjured wrist), and scores on a visual analogue scale for pain were compared between the union and non-union groups using the Mann–Whitney test.

meta-analysis of the primary outcome

In the selected studies, (a combination of ) different questionnaires were used to mea-sure patient-reported outcome. If different questionnaires were used within the same study, these data were pooled in the following way, in order to obtain one summary esti-mate for the PROMs per study. The results for the different questionnaires were adjusted so that they reflected a scale ranging from 0 (maximal disability) to 100 (no disability). Then, the standardized mean difference with 95% confidence interval within each study was calculated using the inverse variance method with fixed effects. These standardized mean differences from the individual studies were meta-analyzed using the method of mean differences with random effects. Meta-analysis of the secondary outcomes prona-tion, supination, flexion, and extension were analyzed separately and reported as an absolute range of motion in degrees. Grip strength of the injured wrist was reported as a percentage of the uninjured wrist and could be pooled between studies without further adjustments. Other secondary outcome measures at follow-up included the percentage of patients with pain and the percentage of patients with DRUJ instability determined by clinical tests. For meta-analysis of the secondary outcomes, means with standard deviations or numbers (%) were extracted from the articles. The meta-analyses for continuous outcome were performed using the method of mean differences with random effects. The meta-analyses for dichotomous outcome were performed using the Mantel–Haenszel method with random effects. Differences in outcome between the union and non-union groups with p < 0.05 were considered statistically significant. The Cochran’s chi-squared test (with significance defined as p < 0.1) and I2-index (with substantial heterogeneity defined as value >50%) were used to evaluate heterogeneity between studies.

RESULTS

Literature search

The search resulted in 488 potentially eligible studies, of which 17 full text articles were analysed for eligibility (Figure 7.1). Eight studies met our inclusion criteria; however, two studies did not report sufficient data to be included in the meta-analysis leaving

Chapter 7

96

six studies available for meta-analysis.24–30 These studies included a total of 135 patients in the union group and 230 in the non-union group. Raw data were available for three out of the six studies.26,29,30 Six patients (three in the union group and three in the non-union group) had participated in both the studies of Buijze and Wijffels; their data were included only once in our meta-analysis.

Description of included studies and outcome measure reporting

The detailed description, reported outcomes, and methodological quality, based on GRADE guidelines, of the included studies in the meta-analysis are summarized in tables 7.1 and 7.2.

Analysis of raw data

The combined raw data of the three studies26,29,30 included the outcome data of 40 pa-tients with union and 65 patients with non-union of the USP. No statistically significant differences between the combined union and non-union groups were found for patient- reported outcomes, range of motion, grip strength, and pain (7.3).

meta-analysis: primary outcome

Patient-reported outcome was measured in four studies26,27,29,30 using (a combination of ) different questionnaires: the Mayo wrist score33 in three studies26,27,30, the Gartland and Werley score34 in two studies26,30, and the Disabilities of the Arm, Shoulder and Hand (DASH) score35 in three studies.26,27,29 No significant difference between the union group (n = 59) and the non-union group (n = 125) for patient-reported outcome based on questionnaires was found (mean difference = 0.07, 95% confidence interval = −0.16 to 0.30) (Figure 7.2). Heterogeneity between the studies was not detected (I2 = 0%).

meta-analysis: secondary outcomes

Data on range of motion (flexion, extension, pronation, and supination) were available for four studies.26,27,29,30 The meta-analyses did not show any significant differences in range of motion between the groups with and without union of the ulnar styloid (7.4). Heterogeneity between studies was detected only for wrist extension. Data on clinical DRUJ instability and pain were available in four25–27,30 and all six studies,24–27,29,30 respec-tively. For these outcome measures, no significant differences were found between the union and non-union groups. No heterogeneity was detected (7.2). Data on grip strength were available for three studies.26,29,30 The meta-analysis showed no significant difference between groups. Heterogeneity was not applicable as these results were based on raw data solely.

97


7

Figure 7.1. Study flow diagram of the systematic review

Chapter 7

98

Tabl

e 7.

1. C

hara

cter

istic

s an

d re

sults

of t

he in

clud

ed s

tudi

es

Stud

yn

unio

nsn

non-

unio

nstr

eatm

ent o

f dis

tal r

adiu

s fr

actu

rem

ean

age

(ran

ge)

anal

yzed

out

com

e us

ed

in th

is m

eta-

anal

ysis

*m

ean

follo

w-u

p (r

ange

) [m

onth

s]si

gnifi

cant

diff

eren

ces

betw

een

grou

ps.

Buijz

e 20

10§

1620

Ope

rativ

e54

(25-

75)

1,2,

3,4,

5,6,

76

Non

e

Kim

201

120

71O

pera

tive

50 (1

8-88

)1,

2,4,

6,7

23 (1

2-48

)N

one

Krae

mer

201

355

46O

pera

tive

and

Cons

erva

tive

56 (1

8-81

)6,

720

(6-4

9)N

one

men

tzel

200

16

29O

pera

tive

and

Cons

erva

tive

596

12be

tter

rang

e of

mot

ion

in

the

unio

n-gr

oup

Wijff

els

2011

§16

18O

pera

tive

56 (2

5-81

)2,

3,4,

5,6,

731

(6-7

4)be

tter

grip

str

engt

h in

the

non-

unio

n gr

oup

Zenk

e 20

09§

2246

Ope

rativ

e64

(25-

94)

1,4,

5,6

14.9

(6-3

8)N

one

§ Raw

dat

a av

aila

ble

for a

naly

sis

* 1) D

ASH

2) M

ayo

Wris

t Sco

re 3

) Gar

tland

and

Wer

ly s

core

, 4) r

ange

of m

otio

n, 5

) grip

, 6) p

ain,

7) D

RUJ i

nsta

bilit

y

99


7

Tabl

e 7.

2. G

RAD

E qu

ality

ass

essm

ent o

f the

incl

uded

stu

dies

.

Stud

ysi

gnifi

cant

diff

eren

ces

betw

een

grou

psst

udy

desi

gnin

cons

iste

ncy#

indi

rect

ness

$Im

prec

isio

nфov

eral

l qua

lity

Buijz

e 20

10§

Non

eO

bser

vatio

nal

nono

serio

usф

фlo

w

Kim

201

1N

one

Obs

erva

tiona

lno

nono

low

Krae

mer

201

3N

one

Obs

erva

tiona

lno

serio

us$$

$se

rious

фф

фve

ry lo

w

men

tzel

200

1be

tter

rang

e of

mot

ion

in th

e un

ion-

grou

pO

bser

vatio

nal

nose

rious

$$$$

serio

usф

фф

фve

ry lo

w

Wijff

els

2011

§be

tter

grip

str

engt

h in

the

non-

unio

n gr

oup

Obs

erva

tiona

lse

rious

##se

rious

$$se

rious

фф

very

low

Zenk

e 20

09§

Non

eO

bser

vatio

nal

nono

nolo

w

§ Ra

w d

ata

avai

labl

e fo

r ana

lysi

s# in

cons

iste

ncy

refe

rs to

une

xpla

ined

het

erog

enei

ty o

f res

ults

$ indi

rect

ness

refe

rs to

an

indi

rect

com

paris

on o

f gro

ups

(e.g

. los

s to

follo

w u

p an

d tr

eatm

ent s

trat

egy)

.Ф

impr

ecis

ion

refe

rs to

stu

dies

with

rela

tivel

y fe

w p

atie

nts

and

few

eve

nts

and

thus

with

wid

e co

nfide

nce

inte

rval

s ar

ound

the

estim

ate

of th

e eff

ect.

## n

o cl

ear e

xpla

natio

n fo

r diff

eren

ce in

grip

str

engt

h.ф

ф N

o D

RUJ i

nsta

bilit

y pr

esen

tф

фф o

nly

one

ques

tiona

ire to

incl

ude

фф

фф le

ss th

an 1

0 pa

tient

s in

PSU

uni

on g

roup

$$ le

ss th

an 5

0%<

clin

ical

follo

w-u

p, n

o in

form

atio

n on

diff

eren

ces

betw

een

popu

latio

ns$$

$ diff

eren

ce in

trea

tmen

t bet

wee

n gr

oups

$$$$

no

info

rmat

ion

on c

ompa

rabi

lity

of g

roup

s

Chapter 7

100

Figure 7.2. Forrest plot illustrating patient reported outcome measure based on pooled questionnaires. USP = ulnar styloid process.

Table 7.3. Analysis of pooled raw data of three included studies

Outcome measurement non-union union p

Patient reported outcome, median (range); n

DASH 0.9 (0-24); 40 4.2 (0-15); 25 0.41

mAYO 82.5 (45-100); 34 75 (45-95); 29 0.13

Gartland & Werley 1.5 (0-12); 34 2 (0-21); 29 0.15

Function (% of non-injured wrist), median (range); n

Flexion 89 (50-117); 35 83 (28.131); 29 0.51

Extension 88 (46-125); 35 92 (38-115); 29 0.63

Pronation 100 (39-114); 35 100 (22-106); 29 0.55

Supination 100 (71-100); 35 100 (22-113); 29 0.32

Grip strength 85 (38-133); 65 87 (34-140); 40 0.92

Pain, median (range); n 0 (0-100); 65 0 (0-66); 38 0.71

101


7

DISCUSSION

Based on the available data, no influence of the osseous union status of the fractured ulnar styloid in adult patients with a DRF could be demonstrated regarding patient-reported outcome, range of motion, presence of pain, or presence of DRUJ instability.

Patient-reported outcome

In the included studies, different questionnaires were used to measure patient-reported outcome. Although generally accepted and often used for evaluation of wrist disorders, validation of these questionnaires for assessing wrist function is not as solid as might be assumed.36 The DASH has been validated to evaluate impact of an upper extremity dis-order but the outcome has a weak correlation with severity of wrist pain. The Gartland and Werley score has not been validated for wrist disorders. This questionnaire contains only one subjective domain and it has to be filled out by the clinician. In addition, for the Mayo Wrist Score validation is lacking.37 This questionnaire contains two out of four subjective domains and has to be filled out by the clinician. Both the Gartland and Werley score and Mayo Wrist Score can be doubted as a true patient-reported outcome. The questionnaires used in the studies selected for this meta-analysis may therefore not be sufficiently responsive for detecting small but clinically relevant differences in self-reported wrist function between patients with and without ulnar styloid union. In terms of responsiveness, the patient-rated wrist evaluation score (PRWE)38 might be a more suitable tool for evaluating wrist outcome in future studies.36 Furthermore, pooling of these data to create a summary estimate may have an unpredic influence on the outcome within a study. This is because different (numbers) of questionnaires were used per study and each questionnaire has different domains. On the other hand,

Table 7.4. Results of the meta-analyses for secondary outcome measurements based on published data from six included studies.

Outcome measurement Included studies # n non-union n union I2 (%) mD/OR* (95% CI) P

Flexion 1,2,5,6 136 60 0 1.07 (−2.82, 4.95) 0.59

Extension 1,2,5,6 136 60 38 −1.56 (−7.23, 4.11) 0.59

Pronation 1,2,5,6 136 60 0 −0.85 (−3.09, 1.38) 0.45

Supination 1,2,5,6 136 60 9 0.30 (−2.02, 3.06) 0.80

Grip 1,5,6 65 40 55 0.38 (−10.57, 11.33) 0.95

DRUJ instability 1,2,3,5 152 104 0 0.93 (0.41, 2.06) 0.85

Pain 1,2,3,4,5,6 211 119 0 0.58 (0.31, 1.06) 0.07

* MD = mean difference, OR = odds ratio, CI = confidence interval# 1) Buijze, 2) Kim, 3) Kraemer, 4) Mentzel, 5) Wijffels, 6) Zenke

Chapter 7

102

a summary estimate includes as much as possible information which reflects the most reliable outcome.

Functional outcome

Overall, no significant influence of the ulnar styloid non-union on range of motion was found. Pronosupination gives rise to a complex rotational movement resulting in a centrode of rotation.39,40 Anatomically, the centrode of rotation can be influenced among others by malunion of the distal radius or DRUJ instability.6,40 Evidence for the influence of distal radius malunion or DRUJ instability on pronosupination is lacking as no analyses including multiple explanatory factors on this topic have been published so far. Hypothetically, distal radius malunion and DRUJ instability may overshadow the influence of an ulnar styloid non-union on pronosupination. The lack of difference in pronosupination between the union and non-union groups in this study may be ex-plained by the coincidental presence of radius malunion in both study groups. Flexion and extension mainly involves the radio-carpal joint and the DRUJ to a lesser extent. Therefore, it may be assumed that the healing status of the ulnar styloid is of minor in-fluence on this movement and probably explains why no flexion/extension differences were found in this meta-analysis comparing USP unions with non-unions. The results of our analyses showed no difference in grip strength at final follow-up. This is consistent with the findings of Tsukazaki.13 An explanation might be the relatively long follow-up for grip measurement. Souer et al.28 showed significantly reduced grip strength during first 6 months in patients with ulnar styloid base fractures, but no difference after 1-year follow-up. The mean follow-up in this meta-analysis for grip strength was 17 months. We therefore conclude, in concordance with Souer et al., that patients had fully recovered from reduced pain and muscle atrophy, due to the treatment, in both groups.

Pain

In this meta-analysis, the percentage of patients with pain at follow-up did not differ be-tween the union and the non-union group. In part, this may be explained by the fact that all reported pain scores were dichotomised, thus disregarding location and intensity, in order to enable pooling of all available data. In the analysis of the pooled raw data of three studies, however, the scores on a visual analogue scale for pain also did not differ between the patients with union and non-union. Ulnar-sided wrist pain can be caused by several anatomical changes of which TFCC lesion is only one. Geissler showed TFCC lesions in 16% and 9% of the patients with and without an ulnar styloid fracture, respec-tively, and shows good results for pain score after a direct ligamenteous treatment.41,42 Lindau et al. showed that complete TFCC tears additional to a dislocated DRF resulted in DRUJ instability in 91% of the patients resulting in worse scores on the Gartland and Werley questionnaire.43 Furthermore, Abid et al. showed higher pain scores in children

103


7

with non-union compared to children with a consolidated ulnar styloid fracture and all the patients with a fair result (17%) who were operated on suffered from TFCC lesions.23 Hauck et al. published data on pain relief after resection of an ulnar styloid non-union in patients with and without TFCC lesions.9 Cerezal and colleagues described several pain syndromes due to non-union or fibrous union of the ulnar styloid. Due to ulnar abutment, impingement of the extensor carpi ulnaris tendon sheet, secondary TFCC perforations, or DRUJ instability pain may persist.44 On the other hand, several other studies did not reveal a difference in pain when comparing united ulnar styloid fractures with pseudoarthrosis of the ulnar styloid fractures without knowledge of TFCC congru-ency.26–29,45 The role for the TFCC in causing wrist pain remains therefore unclear. In the included papers of this meta-analysis, the status of the TFCC was also unknown but it is reasonable to assume that TFCC tears were distributed equally in the USP union and non-union groups. As long as prospective studies evaluating the associations between pain, congruency of the TFCC, and healing status of the ulnar styloid are lacking, the exact mechanism of pain after a DRF will remain unsolved.

DRUJ instability

The theory behind ulnar styloid non-union causing DRUJ instability is based on the in-terruption of the principal stabilizer of the DRUJ, the TFCC. Avulsions of the ulnar styloid base may interrupt the TFCC, as its anatomical insertion is located on the ulnar fovea and ulnar styloid base. In this meta-analysis, no difference in the presence of DRUJ instability was found between the union and the non-union group. This may be explained because the exact level of the ulnar styloid fracture was unknown in one25 of the four included studies.25–27,30 In the other three studies, the number of patients with DRUJ instability was too small for further analysis. Our findings are consistent with those of Lindau and colleagues who also did not acknowledge PSU fracture level and also did not find a difference in DRUJ instability between USP unions and non-unions.46 These findings suggest that DRUJ stability is dependent not only on TFCC congruency but also on more anatomical structures.

Clinical consequences

These data suggest that elective operative fixation of an ulnar styloid non-union is not a beneficial intervention per se. As the result of USP union or non-union does not seem to influence the functional outcome of the DRF, the ulnar styloid should not be the focus of attention during initial treatment. However, operative fixation may be beneficial for individual patients. In a symptomatic wrist with an ulnar styloid non-union after a DRF, complaints may be caused by a variety of diagnoses. Among others, ulnar impaction syndrome, ligamenteous tears, TFCC injuries, and posttraumatic degenerative changes have been described.47 If the pain most probably is related to non-union of the USP,

Chapter 7

104

resection of the ulnar styloid, with or without repair of TFCC, or open reduction and internal fixation of the styloid process has been reported to have good results.9,23,44,48 Buijze et al. questions this outcome as it is unclear if and how the patients who request surgical treatment differ from the average patient with an ulnar styloid non-union and whether improvement after surgery is more than a placebo effect.26

Limitations

A limitation of this study concerns the fact that the quality of the selected studies in our meta-analysis is low or very low according to the GRADE system. However, the meta-analysis provides the best evidence available at present. Although the study results were not found to be heterogeneous for most outcome measures, the included studies involved a variety of patients, for instance, regarding DRF type, treatment method, level, of ulnar styloid fracture and duration of follow-up. The results should therefore be interpreted with caution regarding specific fracture subgroups. In addition, the groups were, despite pooling small which may result in lack of power and weakening of the conclusion.

Conclusion

In conclusion, the results of this meta-analysis indicate that the consolidation status of an accompanying USP has no influence on the patient-reported outcome nor on func-tion, pain, or DRUJ instability after a healed DRF. This might limit the clinical relevance of operative USP fracture fixation. However, as randomization for ulnar styloid union will never be possible, observational studies are the highest level of evidence available for single studies. A meta-analysis based on these studies, especially based on raw data, will result in level 1 evidence; the highest level of evidence producible to evaluate the influence of USP non-union on the outcome of DRFs.

REFERENCES

1. Sammer DM, Shah HM, Shauver MJ et al. The effect of ulnar styloid fractures on patient-rated out-comes after volar locking plating of distal radius fractures. J Hand Surg Am 2009; 34(9): 1595–602.

2. Lindau TR, Aspenberg P, Arner M et al. Fractures of the distal forearm in young adults. An epide-miologic description of 341 patients. Acta Orthop Scand 1999; 70(2): 124–8.

3. Hollingsworth R, Morris J. The importance of the ulnar side of the wrist in fractures of the distal end of the radius. Injury 1976; 7(4): 263–6.

4. Frykman G. Fracture of the distal radius including sequelae—shoulder-hand-finger syndrome, disturbance in the distal radioulnar joint and impairment of nerve function. A clinical and experi-mental study. Acta Orthop Scand 1967; 108(Suppl.): 7–153.

5. Lindau T, Arner M, Hagberg I. Intraarticular lesions in distal fractures of the radius in young adults. A descriptive arthroscopic study in 50 patients. J Hand Surg Br 1997; 22(5): 638–43.

105


7

6. Oskarsson GV, Asser P, Hjall A. Do we underestimate the predictive value of the ulnar styloid affection in Colles fractures? Arch Orthop Trauma Surg 1997; 116(6–7): 341–4.

7. Richards RS, Bennett JD, Roth JH et al. Arthroscopic diagnosis of intra-articular soft tissue injuries associated with distal radial fractures. J Hand Surg Am 1997; 22(5): 772–6.

8. afEkenstam F, Jakobsson OP, Wadin K. Repair of the triangular ligament in Colles’ fracture: no effect in a prospective randomized study. Acta Orthop Scand 1989; 60(4): 393–3396.

9. Hauck RM, Skahen III J, Palmer AK. Classification and treatment of ulnar styloid non-union. J Hand Surg Am 1996; 21(3): 418–22.

10. Kaukonen JP, Karahuarju EO, Porras M et al. Functional recovery after fractures of the distal fore-arm. Analysis of radiographic and other factors affecting the outcome. Ann Chir Gynaecol 1988; 77(1): 27–31.

11. Melone CP, Nathan R. Traumatic disruption of the triangular fibrocartilage complex. Clin Orthop Relat Res 1992; 275: 65–73.

12. Stoffelen D, de Smet L, Broos P. The importance of the distal radioulnar joint in distal radial frac-tures. J Hand Surg Br 1998; 23(4): 507–11.

13. Tsukazaki T, Iwasaki K. Ulnar wrist pain after Colles’ fracture. Acta Orthop Scand 1993; 64(4): 462–4. 14. Villar RN, Marsh D, Rushton N et al. Three years after Colles’ fracture: a prospective review. J Bone

Joint Surg Br 1987; 69(4): 635–8. 15. Kleinman WB. Stability of the distal radioulnar joint: biomechanics, pathophysiology, physical

diagnosis, and restoration of function what we have learned in 25 years. J Hand Surg Am 2007; 32(7): 1086–106.

16. Mikic ZD. Detailed anatomy of the articular disc of the distal radioulnar joint. Clin Orthop Relat Res 1989; 245: 123–32.

17. Palmer AK, Werner FW. The triangular fibrocartilage complex of the wrist— anatomy and func-tion. J Hand Surg Am 1981; 6(2): 153–62.

18. Adams BD, Samani JE, Holley KA. Triangular fibrocartilage injury: a laboratory model. J Hand Surg Am 1996; 21(2): 189–93.

19. Haugstvedt JR, Berger RA, Nakamura T et al. Relative contributions of the ulnar attachments of the triangular fibrocartilage complex to the dynamic stability of the distal radioulnar joint. J Hand Surg Am 2006; 31(3): 445–51.

20. Kikuchi Y, Nakamura T. Avulsion fracture at the fovea of the ulna. A report of two cases. J Hand Surg Br 1998; 23(2): 176–8.

21. May MM, Lawton JN, Blazar PE. Ulnar styloid fractures associated with distal radius fractures: inci-dence and implications for distal radioulnar joint instability. J Hand Surg Am 2002; 27(6): 965–71.

22. Zimmermann R, Rudisch A, Fritz D, Gschwentner M, Arora R. MR imaging for the evaluation of accompanying injuries in cases of distal forearm fractures in children and adolescents. Handchir Mikrochir Plast Chir 2007; 39(1): 60–7.

23. Abid A, Accabled F, Kany J et al. Ulnar styloid fracture in children: a retrospective study of 46 cases. J Pediatric Orthop B 2008; 17(1): 15–9.

24. Mentzel M, Hoss H, Ebinger T et al. Problematik der in Fehlstellung ausgeheilten distalen Radius-faktur. Unfallchirurg 2001; 104(3): 210–214.

25. Krämer S, Meyer H, O’Loughlin P et al. The incidence of ulnocarpal complaints after distal radial fracture in relation to the fracture of the ulnar styloid. J Hand Surg Eur 2013; 38(7): 710–7.

26. Buijze G, Ring D. Clinical impact of united versus nonunited fractures of the proximal half of the ulnar styloid following volar plate fixation of the distal radius. J Hand Surg Am 2010; 35(2): 223–7.

Chapter 7

106

27. Kim JK, Koh YD, Do NH. Should an ulnar styloid fracture be fixed following volar plate fixation of a distal radial fracture? J Bone Joint Surg Am 2010; 92(1): 1–6.

28. Souer JS, Ring D, Matschke S et al. Effect of an unrepaired fracture of the ulnar styloid base on outcome after plate-and-screw fixation of a distal radial fracture. J Bone Joint Surg Am 2009; 91(4): 830–8.

29. Zenke Y, Sakai A, Oshige T et al. The effect of an associated ulnar styloid fracture on the outcome after fixation of a fractures of the distal radius. J Bone Joint Surg Br 2009; 91(1): 102–7.

30. Wijffels M, Ring D. the influence of non-union of the ulnar styloid on pain, wrist function and instability after distal radius fracture. J Hand Microsurg 2011; 3(1): 11–4.

31. Moher D, Liberati A, Tetzlaff J et al. Preferred reporting items for systematic reviews and meta-analysis: the PRISMA statement. BMJ 2009; 339: b2535.

32. Atkins D, Best D, Briss PA et al. Grading quality of evidence and strength of recommendations. BMJ 2004; 328(7454): 1490.

33. Amadio PC, Berquist TH, Smith DK et al. Scaphoid malunion. J Hand Surg Am 1989; 14(4): 679–87. 34. Sarmiento A, Pratt GW, Berry NC et al. Colles’ fractures. Functional bracing in supination. J Bone

Joint Surg Am 1975; 57(3): 311–7. 35. Hudak PL, Amadio PC, Bombardier C. Development of an upper extremity outcome measure: the

DASH (Disabilities of the Arm, Shoulder and Hand). Am J Ind Med 1996; 29(6): 602–8. 36. Changulani M, Okonkwo U, Keswani T et al. Outcome evaluation measures for wrist and hand –

which one to choose? Int Orthop 2008; 32(1): 1–6. 37. Pynsent PB, Fairband JCT, Carr AJ. Outcome measures in orthopaedics and orthopaedic trauma.

2nd ed. Taylor and Francis Ltd.; 2004. 200 pp. 38. MacDermid JC, Turgeon T, Richards RS et al. Patient rating of wrist pain and disability: a reliable

and valid measurement tool. J Orthop Trauma 1998; 12(8): 577–86. 39. Hagert CG. Distal radius fracture and the distal radioulnar joint-anatomical considerations. Hand-

chir Mikrochir Plast Chir 1994; 26(1): 22–6. 40. King GJ, McMurrey RY, Rubenstein JD et al. Kinematics of the distal radioulnar joint. J Hand Surg

Am 1986; 11(6): 798–804. 41. Geissler WB. Arthroscopically assisted reduction of intra-articular fractures of the distal radius.

Hand Clin 1995; 11: 19–29. 42. Geissler WB, Fernandez DL, Lamey DM. Distal radioulnar joint injuries associated with fractures of

the distal radius. Clin Orthop Relat Res 1996; 327: 135–46. 43. Lindau T, Adlercreutz C, Aspenberg P. Peripheral tears of the triangular fibrocartilage complex

cause distal radioulnar joint instability after distal radial fractures. J Hand Surg Am 2000; 25(3): 464–8.

44. Cerezal L, del Pin˜al F, Abascal F et al. Imaging findings in ulnar-sided wrist impaction syndromes. Radiographics 2002; 22(1): 105–21.

45. Yamamoto K, Masaoka T, Shishido T et al. Clinical results of external fixation for unstable Colles fractures. Hand Surg 2003; 8(2): 193–200.

46. Lindau T, Hagbert L, Aldercreutz C et al. Distal radioulnar instability is an independent worsening factor in distal radial fractures. Clin Orthop Relat Res 2000; 376: 229–35.

47. Sachar K. Ulnar-sided wrist pain: evaluation and treatment of triangular fibrocartilage complex tears, ulnocarpal impaction syndrome, and lunotrique-tral ligament tears. J Hand Surg Am 2012; 37(7): 1489–500.

48. Nakamura R, Horii E, Imaeda T et al. Ulnar styloid malunion with dislocation of the distal radioul-nar joint. J Hand Surg Br 1998; 23(2): 173–5.

107


7

APPENDIX CHAPTER 7

A systematic search was without any limit in publication date. The search strategy was for PubMed: (ulnar styloid OR ulnar styloid* OR ulnar styloid OR Ulnar styloid fractures OR Ulnar styloid fracture OR styloideus ulnae OR styloideus ulnar OR styloid ulnae) AND (Distal Radius Fractures OR Distal Radius Fracture OR ‘‘Distal Radius Fractures’’ OR ‘‘Distal Radius Fracture’’ OR ‘‘Distal Radial Fractures’’ OR ‘‘Distal Radial Fracture’’), for EMBASE: ((ulnar styloid OR ulnar styloid* OR ulnar stiloid OR Ulnar styloid fractures OR Ulnar styloid fracture OR styloideus ulnae OR styloideus ulnar OR styloid ulnae).mp OR (ulna fracture/AND styloid.mp)) AND ((Distal Radius Fractures OR Distal Radius Fracture OR ‘‘Distal Radius Fractures’’ OR ‘‘Distal Radius Fracture’’ OR ‘‘Distal Radial Fractures’’ OR ‘‘Distal Radial Fracture’’).mp OR (radius fracture/AND distal.mp)), for Web of Science: TS=((ulnar styloid OR ulnar styloid* OR ulnar stiloid OR styloideus ulnae OR styloideus ulnar OR styloid ulnae) AND (Distal Radius Fracture* OR Distal Radial Fracture*)), for COCHRANE: #1 (ulnar styloid OR ulnar styloid* OR ulnar stiloid OR Ulnar styloid fractures OR Ulnar styloid fracture OR styloideus ulnae OR styloideus ulnar OR styloid ulnae) #2 (Distal Radius Fractures OR Distal Radius Fracture OR ‘‘Distal Radius Fractures’’ OR ‘‘Distal Radius Fracture’’ OR ‘‘Distal Radial Fractures’’ OR ‘‘Distal Radial Fracture’’) #3 MeSH de-scriptor Radius Fractures explode all trees #4 (distal*) #5 (#3 AND #4) #6 (#2 OR #5) #7 (#1 AND #6), for CINAHL: ((ulnar styloid OR ulnar styloid* OR ulnar stiloid OR styloideus ulnae OR styloideus ulnar OR styloid ulnae) AND (Distal Radius Fracture* OR Distal Radial Fracture*)), for Academic Search Premier: ((ulnar styloid OR ulnar styloid* OR ulnar stiloid OR styloideus ulnae OR styloideus ulnar OR styloid ulnae) AND (Distal Radius Fracture* OR Distal Radial Fracture*)), for ScienceDirect: All text: (ulnar styloid OR ulnar styloid* OR ulnar stiloid OR Ulnar styloid fractures OR Ulnar styloid fracture OR styloideus ulnae OR styloideus ulnar OR styloid ulnae) AND (Distal Radius Fractures OR Distal Radius Fracture OR ‘‘Distal Radius Fractures’’ OR ‘‘Distal Radius Fracture’’ OR ‘‘Distal Radial Fractures’’ OR ‘‘Distal Radial Fracture’’), for Springer: In Summary: ulnar styloid AND Distal Radius Fracture, for Wiley Blackwell: ulnar styloid AND Distal Radius, for LWW: ((ulnar styloid OR ulnar styloid* OR ulnar stiloid OR Ulnar styloid fractures OR Ulnar styloid fracture OR styloideus ulnae OR styloideus ulnar OR styloid ulnae) AND (Distal Radius Fractures OR Distal Radius Fracture OR ‘‘Distal Radius Fractures’’ OR ‘‘Distal Radius Fracture’’ OR ‘‘Distal Radial Fractures’’ OR ‘‘Distal Radial Fracture’’)).af, for HighWire: Title-abstract: ulnar styloid Distal Radius and for Informahealth: Fulltext ulnar styloid Distal Radius fracture.

12345678910111213

Chapter 8Clinical DRUJ instability does not influence the long term functional outcome of conservatively treated

distal radius fractures

Chapter 8

110


submitted

ABSTRACT

Objective: The presence of distal radioulnar joint (DRUJ) instability remains often un-noticed initially, but may worsen functional outcome of distal radius fractures (DRF). The aim of this study was to evaluate the influence of concurring clinical DRUJ instability on the outcome of conservatively treated DRF. Methods: In a retrospective cohort study, all unilateral, conservatively treated DRF patients were invited for physical examination, CT-scan of both wrists and filling out questionnaires. Static and dynamic DRUJ instability were clinically tested. Results: Forty-nine DRF patients with a mean follow-up of 4.2 years (SD 0.5) were as-sessed. Seventeen patients tested positive for DRUJ instability. No differences were found in baseline characteristics between the DRUJ stable and unstable group. Apart from wrist flexion, no statistical significant differences in outcome was found between patients with and without DRUJ instabilityConclusion: The presence of clinical DRUJ instability does not seem to affect functional outcome of conservatively treated distal radius fractures at long term follow-up.

111

DRUJ instability does not influence functional outcome of the patients with a conservatively treated distal radius fracture

8

INTRODUCTION

Distal radius fractures (DRF) comprise one in six fractures that present to the emergency department.1-3 The treatment decision between surgical or conservative fracture man-agement is based on several factors including the type and complexity of the fracture, bone quality, the surgeon’s experience and patient characteristics.4 The majority (50-80%) of DRF is still treated conservatively, although there is an increasing tendency towards surgical treatment.5,6

One of the complicating factors with a potentially negative influence on the out-come of DRF treatment is concurring distal radial ulnar joint (DRUJ) instability. The incidence of DRUJ instability after DRF varies from 0 to 35% at one year after a distal radius fracture. 7-10 Lindau found that DRUJ instability was independently associated with worse outcome after DRF, showing significantly more pain and lower wrist scores for DRUJ-unstable patients.7,8 These findings resulted from DRF patients after a variety of treatment modalities, amongst which surgery. In this study the surgery itself may have influenced the outcome.7,8 Currently, it is unknown how the outcome of non-operatively treated DRF is influenced by coexisting DRUJ instability. The aim of this study therefore was to assess the influence of clinical DRUJ instability on the long-term outcome of conservatively treated DRFs.

PATIENTS AND mETHODS

All adults treated conservatively for a DRF between May 2008 and February 2010 in the Leiden University Medical Center were eligible for inclusion in this study. Patients were excluded if they were 1) unwilling or unable to provide informed consent or had 2) systemic diseases such as rheumatoid arthritis and SLE, or had 3) contralateral wrist injury. All eligible patients received an invitational letter for a study visit according to the protocol, as approved by the institutional medical ethics review board.

visit

During the research visit DRUJ instability of both the injured and non-injured wrist was tested by an experienced trauma-surgeon not involved in the initial treatment and unaware of the injured side. Static instability was tested using the stress test.8,11,12 The test was considered positive if there was more anterioposterior movement of the ulna, relative to the stabilized radius, in the injured wrist compared to the uninjured wrist. Dynamic instability was tested using the clunk test.13 The test was considered positive if a “clunk” was palpable for either the patient or examiner, during pronosupination of the lower arm with the wrist held between the examinator’s thumb and index finger.

Chapter 8

112

Further physical examination of both wrists consisted of measurement of range of motion and grip- and pinch strength for both the injured and non-injured wrist. Range of motion was measured using a goniometer. Grip and pinch strength were based on the mean value of three successive measurements using a Jamar® Hydraulic Hand Dyna-mometer and a Jamar® Hydraulic Pinch Gauge respectively. Maximum range of motion of the injured wrist was expressed in degrees and as a percentage of the non-injured wrist.

Radiological evaluation

Conventional trauma radiographs in lateral and anterioposterior view were evaluated by one observer (MW) to determine the fracture classification according to the Comprehen-sive Classification of Fractures.14 CT scans of both wrists were obtained and evaluated for radiocarpal arthritic changes according to the classification of Knirk and Jupiter and for union of the ulnar styloid, if a fracture was previously present.15 The CT-scans were made at 3-mm intervals using an Aquilion One (Toshiba Medical Systems). Axial sections of the wrist were obtained with the arm outstretched position above the head in prone position to minimize the exposure to radiation.

Patient reported outcome

Participants scored pain on a visual analogue scale five times for the posttraumatic wrist, indicating perceived pain 1) in rest, 2) with 10kg loadbearing with the elbow extended and 3) with 10kg loadbearing with the elbow 90˚ flexed, 4) during pronosupination without loadbearing and 5) during pronosupination with 10kg of loadbearing. Further-more, the Disabilities of the Arm, Shoulder and Hand (DASH) score, Modified Mayo Wrist Score (MMWS) and Gartland and Werley score were filled out by the participants.16-18

Statistical analysisBaseline characteristics and outcome scores of the clinically DRUJ stable and unstable

groups were compared. The static DRUJ unstable group was compared to the stable group, as was the dynamic DRUJ unstable group. Continuous data were compared between groups by the independent samples t-test, categorical data by the Pearson’s Chi-square test. Analyses were performed using SPSS version 20 (SPSS Inc, Chicago IL). P-values below 0.05 were considered statistically significant.

RESULTS

In total, 156 patients met the inclusion criteria and were sent an invitational letter for a study visit. Thirty-four patients were lost to follow-up and 73 were unwilling to participate. The resulting 49 participants provided written informed consent before

113


8

examination. No differences were found in age, gender or fracture classification compar-ing participants with no participants (data not shown).

The study group consisted of 10 men and 39 women. Mean age was 60.8 years (SD 16.2). Mean follow-up after trauma was 4.2 years (SD 0.5). Seventeen of the 49 patients tested positive for DRUJ instability. The groups with and without DRUJ instability were similar with respect to age, dominant hand injured, fracture characteristics and degree of radiocarpal arthritis. (Table 1)

Table 8.1. Baseline characteristics of patients with static distal radioulnar joint instability compared to pa-tients with a stable distal radioulnar joint.

DRUJ stable (n=32) DRUJ instability (n=17) p-value

Age (years)[SD] 61.5 [14.6] 59.5 [19.3] .686

Follow-up (years)[SD] 4.2 [0.5] 4.1 [0.5] .767

AO classification (n) .448

A 13 10

B 4 1

C 15 6

Dominant hand injured (n) .426

yes 15 10

no 17 7

PSU-union (n) .185

yes 7 4

no 6 7

no PSU fracture 19 6

Radio carpal arthritisa(n) .138

0 1 3

1 14 7

2 13 3

3 4 4 a 0=none, 1=slight joint-space narrowing, 2=marked joint-space narrowing, osteophyte formation,3=bone-on-bone, osteophyte formation, cyst formation

Range of motion and strength

In patients with an unstable DRUJ flexion and extension averaged 81° (range, 58–102°) and 89° (range, 58–110°) respectively. Radial deviation averaged 25° (range 5–40°) and ulnar deviation averaged 40° (range 25–58°). The average pronation and supination measured 84° (range, 60–100°) and 89° (range, 75–110°) respectively. In patients with a stable DRUJ of the injured wrist flexion averaged 68° (range, 35–92°) and extension 85° (range, 55–105°). Radial deviation averaged 24° (range 6–40°) and ulnar deviation aver-aged 40° (range 21–65°). The average pronation and supination measured 87° (range, 68–109°) and 92° (range, 60–118°) respectively. Function expressed as percentage of the

Chapter 8

114

uninjured arm is shown in Table 2. Flexion was found to be statistical significantly better in the DRUJ unstable group. Further results did not differ between patients with and without DRUJ instability.

In patients with an unstable DRUJ the grip and pinch strength averaged 98% (range, 59-115%) and 101% (range, 51-133%) respectively, indexing the uninjured for the injured wrist. In patients with a stable DRUJ, the grip and pinch strength averaged 93% (range, 63-132%) and 95% (range, 50-161%) respectively, indexing the uninjured for the injured wrist. No differences in strength were found between the groups (Table 2).

Table 8.2. Functional outcome parameters of patients with stable or unstable distal radioulnar joint. Re-sults are expressed as mean (SD) unless indicated otherwise.

DRUJ stable (n=32)

DRUJ unstable (n=17)

p-value

Flexion in degrees, mean (range) 68 (35-92) 81 (58-102)

% of non-injured wrist 0.93 (0.13) 1.01 (0.15) .04

Extension in degrees, mean (range) 85 (55-105) 89 (58-110)


Pronation in degrees, mean (range) 87 (68-109) 84 (60-100)


Supination in degrees, mean (range) 92 (60-118) 89 (75-110)


Radial deviation in degrees, mean (range) 24 (6-40) 25 (5-40)


Ulnar deviation in degrees, mean (range) 40 (21-65) 40 (25-58)


Grip strength, % of non-injured wrist 0.93 (0.13) 0.98 (0.12) .25

Pinch strength, % of non-injured wrist 0.95 (0.22) 1.01 (0.22) .34

DASH 7.9 (16.3) 10.05 (9.72) .63

mmWS 87.03 (12.9) 87.06 (10.47) .99

Gartland and Werly 4.2 (3.66) 4.9 (3.47) .49

Pain injured wrist in rest 4.7 (16.7) 5.3 (15.05) .90

Pain injured wrist, carrying 10kg, with elbow extended 9.3 (18.7) 11.8 (23.78) .69

Pain injured wrist, carrying 10kg, with elbow flexed 7.7 (19.6) 10.6 (20.5) .63

Pain injured wrist during pronosupination without load 3(11.4) 0 (0) .29

Pain injured wrist during pronosupination with 10kg loadbearing

8.9 (21.1) 11.2 (22.05) .72

115


8

Patient reported outcome

Ten of the DRUJ unstable patients revealed only static DRUJ instability, of which 2 suffered from wrist pain in rest and seven patients showed both static and dynamic instability, of which 1 suffered from wrist pain in rest.

In the DRUJ unstable group, three patients indicated pain in the injured wrist in rest with a mean of 5.3 (range, 0-50). The mean outcome for pain, with 10kg loadbearing with the elbow extended, with 10kg loadbearing with the elbow 90˚ flexed, during pronosupination without loadbearing and during pronosupination with 10kg of load-bearing on the VAS was 11.8 (range 0-70), 10.6 (range 0-60), 0.0 (range 0-0) and 11.2 (range 0-70) respectively. Mean DASH score was 10 (range 0-28). One patient did not fulfill the DASH. The MMWS was excellent or good in 16 and poor in one patient. The Gartland and Werley ratings were excellent in 5 patients, good outcome in 9 patients and fair in 3 patients.

In the DRUJ stable group, three patients indicated pain in the injured wrist in rest with a mean of 4.7 (range 0-80). Average outcome for pain with 10kg loadbearing with the elbow extended, with 10kg loadbearing with the elbow 90˚ flexed, during pronosupina-tion without loadbearing and during pronosupination with 10kg of loadbearing on the VAS was 9.3 (range 0-60), 7.7 (range 0-90), 3.0 (range 0-60) and 8.9 (range 0-80) respec-tively. Mean DASH score was 7.9 (range 0-68). The MMWS ratings were excellent or good in 25 patients, satisfactory in 5 and poor in 2 patients. The Gartland and Werley ratings were excellent and good outcome in 25 patients and satisfactory or poor in 7 patients.

There were no significant differences between DRUJ stable and instable groups in terms patient reported outcomes (Table 2). Comparing patients with static or dynamic DRUJ instability separately to stable DRUJ patients, no statistical significant differences were found (data not shown).

DISCUSSION

Concurring DRUJ instability is assumed to be an independent factor for poor functional outcome in conservatively and operatively treated DRF.8 This study analysed the relation between DRUJ instability and functional outcome in a group of conservatively treated DRF patients and found that patients with clinical DRUJ instability, after consolidation of the DRF, had a long-term functional outcome similar to that of patients after DRF without DRUJ instability with a significantly better wrist flexion. To our knowledge no previous studies focussed on conservatively treated patients solely.

Chapter 8

116

Function

In the present study, only a significant better flexion of the wrist was found in the DRUJ unstable patients. No further differences in function or strength were found, compar-ing patients with a stable DRUJ to patients with an unstable DRUJ. Since flexion and extension of the wrist primarily concern the radiocarpal joint and not so much the DRUJ, finding a difference was not anticipated for this motion. The greater range of flexion in the DRUJ unstable group may be spurious given the relatively small number of patients and the absence of other plausible explanations. However, the expected difference in pronosupination, a movement mainly involving the DRUJ, was not found. A reason for this may be the influence of muscle dependent stabilizers of the DRUJ, such as the exten-sor carpi ulnaris tendon, the pronator quadratus muscle and the radioulnar interosseous membrane.19-21 During pronosupination the muscles tighten resulting in a more stable DRUJ, independent of ligamentous stabilization. These muscle-tension dependent stabilizers may also be the reason for absence of difference in grip- and pinch strength; a finding corresponding with the results of Lindau et al.22 Since muscle relaxation is war-ranted during the clinical tests, the DRUJ is no longer supported resulting in a positive testing result.

Ulnar styloid

DRUJ instability results from malfunctioning of joint stabilizing structures. These stabiliz-ers are, among others, ligamentous and therefore invisible on conventional radiographs and computed tomography (CT) without contrast. Secondary signs may be visualized using these radiological techniques. Since the triangular fibrocartilage complex (TFCC) attaches to the ulnar styloid process (USP), non-union of the USP may indicate loss of TFCC as a stabilizing factor. Static and dynamic DRUJ instability was found in 33% and 17% respectively of the patients in the current study. No difference was found in the number of ulnar styloid non-unions in DRUJ unstable patients compared to DRUJ stable patients. This implies that the TFCC is not the only stabilizing structure and that non-union of the ulnar styloid has no influence on DRUJ stability, which corresponds with literature.9,10,23-26

Pain

According to Stoffelen et al. DRUJ instability may cause ongoing wrist pain.27 Lindau et al. found no statistical difference in pain comparing lax DRUJ patients with DRUJ stable patients.22 Similarly, in this study we found no statistically significant difference in pain between patients with or without clinical DRUJ instability. The absent difference in pain scores may be due to the long follow-up of this (4 years) and Lindau’s study (6 years), compared to the follow up of one year in the study of Stoffelen et al. Still these conclusions should be interpreted with caution since ongoing pain after distal radius

117


8

fractures can be caused by several factors which are not all evaluated in this and other studies.22,28-30

Shortcomings

The shortcomings of this study include the small number of patients analysed, due to the loss of follow-up of many patients and refusal to participate of many others. However, no differences in age or fracture type was found comparing participant with no participants so the participants may be assumed to be representative for the whole group although we were not informed about residual complaints in non-participants. Another study limitation is that, although widely used, the reliability and accuracy of the tests for determination of clinical DRUJ instability is uncertain. 8,13,27,31 This may be due to the subjective qualification of “more laxity compared to the non-injured wrist” when using the stress test. In the absence of other clinical tests, the stress test and clunck test were used to mimic daily clinical practice and enable comparison of the results with published literature.

CONCLUSION

DRUJ instability does not affect clinical outcome of conservatively treated distal radius fractures after long term follow-up. Conservative treatment of secondarily diagnosed DRUJ instability after a DRF, seems to be a justified treatment.

REFERENCES

1. Hollingsworth R, Morris J. The importance of the ulnar side of the wrist in fractures of the distal end of the radius. Injury. 1976;7;4:263-266

2. Lindau TR, Aspenberg P, Arner M, Redlundh-Johnell I, Hagberg L. Fractures of the distal forearm in young adults. An epidemiologic description of 341 patients. Acta Orthop Scand. 1999;70:124-128

3. Sammer DM, Shah HM, Shauver MJ, Chung KC. The effect of ulnar styloid fractures on patient-rated outcomes after volar locking plating of distal radius fractures. J Hand Surg Am. 2009;34:1595-1602

4. Karagiannopoulos C, Sitler M, Michlovitz S, Tierney R. A descriptive study on wrist and hand sensorimotor impairment and function following distal radius fracture intervention. J Hand Ther. 2013;26;3:204-214

5. Nellans KW, Kowalski E, Chung KC. The epidemiology of distal radius fractures. Hand Clin. 2012;28:113-125

6. Taras JS, Ladd AL, Kalainov DM, Ruch DS, Ring DC. New concepts in the treatment of distal radius fractures. Instr Course Lect. 2010;59:313-332

7. Lindau T, Adlercreutz C, Aspenberg P. Peripheral tears of the triangular fibrocartilage complex cause distal radioulnar joint instability after distal radial fractures. J Hand Surg Am. 2000;25;3:464-468

Chapter 8

118

8. Lindau T, Hagberg L, Adlercreutz C, Jonsson K, Aspenberg P. Distal radioulnar instability is an independent worsening factor in distal radial fractures. Clin Orthop Relat Res. 2000;376:229-235

9. Wijffels M, Ring D. The influence of non-union of the ulnar styloid on pain, wrist function and instability after distal radius fracture. J Hand Microsurg. 2011;3:11-4.

10. Krӓmer S, Meyer H, O’Loughlin P, Vaske B, Krettek C, Gaulke R. The incidence of ulnocarpal com-plaints after distal radial fracture in relation to the frature of the ulnar styloid. J Hand Surg Eur. 2013:38:710-717

11. Morrissy RT, Nalebuff EA. Dislocation of the distal radioulnar joint: anatomy and clues to prompt diagnosis. Clin Orthop Relat Res. 1979;144:154-158

12. Pirela-Cruz MA, Goll SR, Klug M, Windler D. Stress computed tomography analysis of the distal radioulnar joint: a diagnostic tool for determining translational motion. J Hand Surg Am. 1991;16:75-82

13. Jupiter JB. Commentary: the effect of ulnar styloid fractures on patient-rated outcomes after volar locking plating of distal radius fractures. J Hand Surg Am. 2009;34:1603-1604

14. Müller ME, Allgöwer M, Schneider R, Willenegger H. Manual of internal fixation, 3rd edn. New York: Springer, 1991

15. Knirk JL, Jupiter JB. Intra-articular fractures of the distal end of the radius in young adults. J Bone Joint Surg Am. 1986;68;5:647-659

16. Hudak PL, Amadio PC, Bombardier C. Development of an upper extremity outcome measure: The DASH (Disabilities of the Arm, Shoulder and Hand). Am J Ind Med. 1996;29:602-608.

17. Amadio PC, Berquist TH, Smith DK, Ilstrup DM, Cooney WP 3rd, Linscheid RL. Scaphoid malunion. J Hand Surg Am. 1989;14:679-687

18. Gartland JJ Jr, Werley CW. Evaluation of healed Colles’ fractures. J Bone Joint Surg Am. 1951;33:895-907

19. Garcia-Elias M. Soft-tissue anatomy and relationsships about the distal ulna. Hand Clin. 1998;14:165-76.

20. Johnson R K, Shrewsbury MM. The pronator quadratus in motions and in stabilization of the radius and ulna at the distal radioulnar joint. J Hand Surg Am. 1976;1:205-209.

21. Hotchkiss RN, An KN, Sowa DT, Basta S, Weiland AJ. An anatomic and mechanical study of the interosseuos membrane of the forearm. Pathomechanics of proximal migration of the radius. J Hand Surg Am. 1989;14:256-261.

22. Lindau T, Runnquist K, Aspenberg P. Patients with laxity of the distal radioulnar joint after distal radial fractures have impaired function, but no loss of strength. Acta Orthop Scand. 2002;73:151-156

23. Buijze G, Ring D. Clinical impact of united versus nonunited fractures of the proximal half of the ulnar styloid following volar plate fixation of the distal radius. J Hand Surg Am. 2010;35:223-227.

24. Kim JK, Koh YD, Do NH. Should an ulnar styloid fracture be fixed following volar plate fixation of a distal radial fracture? J Bone Joint Surg Am. 2010;92:1-6.

25. Souer JS, Ring D, Matschke S, Audige L, Marent-Huber M, Jupiter JB. Effect of an unrepaired frac-ture of the ulnar styloid base on outcome after plate-and-screw fixation of a distal radial fracture. J Bone Joint Surg Am. 2009;91:830-838.

26. Zenke Y, Sakai A, Oshige T, Moritani S, Nakamura T. The effect of an associated ulnar styloid fracture on the outcome after fixation of a fractures of the distal radius. J Bone Joint Surg Br. 2009;91;102-107

27. Stoffelen D, De Smet L, Broos P. The importance of the distal radioulnar joint in distal radial frac-tures. J Hand Surg Br. 1998;23:507–511

119


8

28. Watanabe A, Souza F, Vezeridis PS, Blazar P, Yoshioka H. Ulnar-sided wrist pain. II. Clinical imaging and treatment. Skeletal Radiol. 2010;39:837-857

29. Hauck RM, Skahen J 3rd, Palmer AK. Classification and treatment of ulnar styloid non-union. J Hand Surg. 1996;21:418-422

30. Cerezal L, del Piñal F, Abascal F, Garcia-Valtuille R, Pereda T, Canga A. Imaging findings in ulnar-sided wrist impaction syndromes. Radiographics. 2002;22:105-121

31. Szabo RM. Distal radioulnar joint instability. J Bone Joint Surg. 2006;88:884–894

12345678910111213

Part IvDelayed treatment

12345678910111213

Chapter 9The extended flexor carpi radialis approach for

partially healed malaligned fractures of the distal radius

Chapter 9

124

M.M.E. Wijffels, J.L. Orbay, I. Indriago, D. Ring

Injury. 2012;43(7);1204–8

ABSTRACT

Purpose: The aim of the study is to evaluate the safety and utility of the extended flexor carpi radialis (FCR) exposure and volar locking plate fixation for partially healed ma-laligned fractures of distal radius.Materials and methods: Thirty-five patients with a partially healed malaligned fracture of the distal radius had realignment of the fracture using an extended FCR approach (release of the insertion of the brachioradialis and dorsal periosteum) and volar locked plate and screw fixation.Results: Retrospective review, an average of 20 months after the index operation, pa-tients identified an average wrist extension of 68°, flexion of 64°, pronation of 84° and supination of 85°. Radial inclination, volar tilt and ulnar variance significantly improved compared to preoperative radiographs. All fractures healed, and there were no infec-tions, implant loosening or breakage or tendon ruptures.Conclusions: This study demonstrated that the extended FCR approach is safe and effec-tive as a treatment method for nascent malunions of the distal radius.

125

The extended flexor carpi radialis approach for partially healed malaligned fractures of the distal radius

9

INTRODUCTION

Open reduction and internal fixation of a fracture of the distal radius becomes more difficult as the fracture begins to heal, particularly when the bone is osteoporotic. Incipi-ent healing and contracture of the soft tissues make it difficult to realign the fracture with manipulative reduction, use of a small external fixator or use of the plate as a reduc-tion device by fixing it to the distal fragments first. An alternative is to mobilise incipient fracture callus and expose and release the radial and dorsal periosteum/soft-tissue constraints, thereby mobilising the fracture fragments and making standard reduction and fixation techniques more feasible. It is possible to access the dorsal periosteum and divide it via subperiosteal exposure of the radial shaft and pronation of the radius away from the wrist and hand. This exposure, with release of the dorsal periosteum in combi-nation with opening of the first dorsal compartment and release of the brachioradialis, has been referred to as the extended flexor carpi radialis (FCR) exposure of the distal radius.1 The purpose of this study was to evaluate the safety and utility of the extended FCR exposure followed by volar locking plate fixation for partially healed malaligned fractures of the distal radius.


Participants

From 2001 to 2006, two surgeons treated 50 patients with dorsally displaced partially healed malaligned fractures of the distal radius using an extended FCR exposure and volar plate and screw fixation at two different centres (Figure 9.1). For the purposes of this review, malalignment was defined as 15° or greater dorsal angulation of the articular surface of the distal radius on a lateral radiograph or greater than 2 mm of ulnar posi-tive variance on the posteroanterior radiograph. The inclusion criterion was fracture of the distal radius that was stabilised using open reduction and internal fixation with a volar fixed angle plate using an extended FCR exposure, between 14 and 100 days after fracture. Using a protocol approved by our Human Research Committee, patients with fewer than 12 months of follow-up were excluded, leaving a cohort of 35 patients re-viewed retrospectively. Ten men and 25 women with an average age of 51 years (range, 22–82 years) met the inclusion criteria. In 16 patients, the right hand was injured (14 dominant) and in 19 patients the left arm was injured (4 dominant). According to the Comprehensive Classification of Fractures of Long Bones system, there were seven A2 fractures, 13 A3 fractures, six C1 fractures, eight C2 fractures and one C3 fracture.2,3 The initial treatment was operative in 10 patients and non-operative in 25 patients (closed reduction and cast immobilization). Among the 10 operatively treated patients, fixation

Chapter 9

126

consisted of external fixation in three patients, percutaneous pinning in four patients, conventional (non-locked) volar plating in two patients and a combination of external fixation and non-locked volar plating in one patient. The time from injury to the index surgery averaged 27 days (range, 14–56 days).

Operative technique

The skin incision lies over the FCR longus tendon from the distal pole of the scaphoid approximately 6–8 cm proximally (Figure 9.2(a)). The transverse wrist creases are crossed obliquely. The sheath of the FCR tendon is incised and the FCR tendon is retracted ul-narly (Figure 9.2(b)). The radial artery is left in place and does not need to be identified. The space between the flexor tendons and the volar surface of the pronator quadratus, Parona’s space, is then developed. This exposes the distal radius, the pronator quadratus muscle and the anterior wrist capsule (Fig. 9.2(c)). The pronator quadratus muscle is released by slicing the distal and lateral borders with an L-shaped incision (Figure 9.2(d)).

An extension of the described classic FCR-approach can be done in three steps: release of the first dorsal compartment and the insertion of the brachioradialis (Figure 9.3(a)), subperiosteal dissection and pronation of the proximal radial (shaft) fragment (Figure 9.3(b)) and incision of the dorsal periosteum (Figure 9.3(c)). The use of a bone clamp as a handle facilitates this action. The fracture must be mobilised with the callus separated

A B

Figure 9.1. Anteroposterior (A) and lateral (B) radiographs of a partially healed dorsally displaced intra-articular fracture of the distal radius 3 weeks after injury.

127


9and removed. After the periosteum is divided dorsally, the proximal radial fragment is repositioned. Reduction and internal fixation are then performed as for an acute fracture. Flexion and dorsal pressure achieve reduction and the fracture is provisionally pinned – in this case through the plate (Figure 9.4(a) and (b)). The final screws are ap-plied (Figure 9.4(c)) and the brachioradialis and pronator are repaired, if possible (Figure 9.4(d)). The fracture callus removed when mobilising the fracture is placed in the defect that resulted from realignment. No other bone graft or bone-graft substitute is needed.

Postoperative management

Finger motion and forearm rotation are encouraged immediately. A removable splint is provided for comfort. Light activities of daily living are encouraged. Wrist motion exer-cises are added as comfort allows. Resistive exercises are initiated 6 weeks after surgery.

Evaluation

Range of motion was measured using a goniometer. All patient files were reviewed for complications and subsequent surgeries. Pre- and postoperative radiographic measure-

A A

A

A

Figure 9.2. Figures taken from several different patients illustrate the exposure. (A) The skin incision is straight along the flexor carpi radialis longus tendon and zig-zags over the transverse wrist creases at its distal margin. (B) Incision of the floor of the flexor carpi radialis sheath. (C) The pronator quatratus is ex-posed. (D) Subperiosteal elevation of the pronator quadratus exposes the volar surface of the distal radius.

Chapter 9

128

ments included dorsal tilt of the articular surface of the distal radius, radial inclination, ulnar variance and intra-articular gap and step.


Pre- and postoperative measurements were compared using dependent sample t-test for continuous data. P-values of <0.05 were considered statistically significant.

RESULTS

The patients were evaluated an average of 20 months (range, 14–54 months) after the index operative procedure. The patients achieved a final average wrist extension of 68° (range, 50–80°), wrist flexion of 64° (range, 30–90°), pronation of 84° (range, 70–100°) and supination of 85° (range, 79–90°). Preoperative radiographic measurements in-cluded an average dorsal tilt of the articular surface of the distal radius of 15° (range, 2–35° dorsal tilt), average radial inclination of 28° (range, 8–35° radial inclination) and average radial shortening by ulnar variance of 3.5 mm (range, 2.5 mm ulnar negative to 8 mm ulnar positive). The average intra-articular gap measured 0 mm (range, 0–3

A B

C

Figure 9.3. (A) The brachioradialis is z-lengthened for later repair. (B) The periosteum is elevated off the dorsal radius and the radial shaft is grasped with a clamp. (C) The radius shaft is pronated away from the forearm and the distal radius. Cal-lus is removed and the fracture is mobilised as this is done. The articular fracture can also be mobil-ised. The dorsal periosteum is divided.

129


9

mm), and the average intra-articular step measured 0 mm (range,0–2 mm). The final radiographic parameters averaged 7° of volar angulation (range 10° of volar angulation to 6° of dorsal angulation) of the distal radial articular surface on the lateral radiograph, 20° (range, 15–28°) of ulnarward inclination on the posteroanterior view and neutral ulnar variance (range, 4 mm of ulna-negative to 2 mm ulna-positive ulnar variance). No incongruity of the distal radial articular surface was observed on follow-up radiographs. With the exception of the intra-articular step (P = 0.06), all radiological parameters had statistically significant improvement (P < 0.05) compared to preoperative measurements (Figure 9.5).

A

B

C

DFigure 9.4. (A) A combination of flexion and dorsal pressure achieved reduction. Provisional fixation is achieved with a Kirschner wire or drill through the plate. (B) An introperative image intensifier view shows the provisional reduction and fixation. (C) Final plate and screw fixation. (D) An attempt is made to cover the plate by repairing first the brachioradialis and then the pronator quatratus to the repaired brachiora-dialis.

Chapter 9

130

There were no infections, non-unions or osteonecrosis. One patient lost 5° of palmar angulation on the lateral radiograph compared to the immediate postoperative radio-graphs. There were no tendon ruptures, and none of the implants has been removed.

DISCUSSION

This study documented good results with few complications using the extended FCR exposure for release of soft tissues and fracture callus to facilitate mobilisation of par-tially healed malaligned fractures of the distal radius. Maintaining the ulnar soft-tissue attachments to the radial shaft seems to preserve adequate blood supply, and non-union, infection and osteonecrosis have not been encountered to date.4 The patients in this series had an average correction of 22° of palmar tilt and 3.5 mm of ulnar variance. The result was a mean arc of wrist motion of 134°, evenly balanced between flexion and extension and a mean total arc of forearm rotation of 174°. These results compare favourably with the reported results for dorsal realignment at an early (partially healed) or mature stage, surgery performed through a volar exposure and even volarly ap-proached acute fractures of the distal radius.5–10

A BFigure 9.5. Post-operative anteroposterior (A) and lateral (B) radiographs demonstrate improved align-ment and stable fixation.

131


9

The limitations of this study include dependence on the medical records, lack of comparison to radiographs of the uninjured side as a measure of restoration of anatomy and no assessment of the effects of releasing the brachioradialis muscle. The effect of releasing the brachioradialis will be difficult to isolate, but given that, some surgeons release it routinely when treating a fracture of the distal radius, and given that fractures of the distal radius are common, a randomised trial comparing release with no release of the brachioradialis should be straightforward. Thirty-five patients is a start, but to better define the safety of the extended FCR exposure a much larger cohort of patients from multiple centres would be of value.

We offer the following technical tips: (1) elevate the entire pronator quadratus by incising the periosteum radial and dorsal to the origin of the muscle from the radius; (2) elevate the pronator quadratus subperiosteally; (3) if you plan to repair the brachiora-dialis, make a z-cut for later repair; (4) elevate the dorsal periosteum from the radius; (5) the best place to start removing fracture callus is in the volar fracture line, which is often in bayonet apposition. This can then be extended radially and continued by recreating the fracture deformity by extending the distal fragment. As one works progressively radially and then dorsally, it will be possible to pronate the radius away from the distal fragment, dorsal callus, dorsal periosteum and extensor tendons; (6) protect the exten-sor tendons either by dividing the dorsal periosteum with blunt spreading by scissors or by carefully isolating the dorsal periosteum prior to sharp division; (7) there is nearly always sufficient callus collected during mobilisation of the fracture to fill the defect that results from realignment of the fracture.

The extended FCR exposure may make some surgeons uneasy at a time when the emphasis in fracture care is on preservation of periosteum, muscle attachments and blood supply. This area of the wrist has a relatively robust blood supply and a major portion of this vascularity is supplied from the ulnar side of the radius and is preserved with the extended FCR exposure.4 The release of the brachialis and dorsal periosteum in combination with removal of callus makes realignment of the radius comparable to a fresh fracture. Some surgeons describe alternative techniques such as applying the plate to the distal aspect of the radius first and then using it to help with reduction, but in the authors’ experience, this is very difficult to do without release of the soft tissue and callus, and risks damaging the distal fracture fragment and articular surface when the bone is osteoporotic. There is not much written about the treatment of partially healed fractures, but at conferences and in discussion with colleagues, our impression is that surgeons attempting volar plate fixation of fractures that are partially healed find they sometimes need to make a second dorsal exposure to realign the fracture. The extended FCR essentially provides dorsal exposure from volar. This avoids a second incision and scar; limits dissection and handling of the extensor tendons, which seem more prone to adhesions; and allows the surgeon to work primarily with the stout volar cortex rather

Chapter 9

132

than the thin, often fragmented dorsal metaphyseal cortex. It essentially preserves all of the preferences and advantages of the volar approach while providing a predictable and straightforward way to restore alignment of a partially healed fracture.

REFERENCES

1. Orbay JL, Badia A, Indriago IR et al. The extended flexor carpi radialis approach: a new perspective for the distal radius fracture. Technical Hand Up Extrem Surgery 2001; 5(4): 204–11.

2. Jupiter JB, Fernandez DL. Comparative classification for fractures of the distal end of the radius. Journal of Hand Surgery American Volume 1997; 22A: 563–71.

3. Kreder HJ, Hanel DP, McKee M, et al. Consistency of AO fracture classification for the distal radius. Journal of Bone & Joint Surgery 1996; 78B: 726–31.

4. Lamas C, LlusHy M, Mendez A. et al. Intraosseous vascularity of the distal radius: anatomy and clinical implications in distal radius fractures. Hand (NY) 2009; 4(December (4)): 418–23.

5. Jupiter JB, Ring D. A comparison of early and late reconstruction of malunited fractures of the distal end of the radius. Journal of Bone & Joint Surgery 1996; 78: 739–48.

6. Fernandez DL. Correction of post-traumatic wrist deformity in adults by osteotomy, bone-grafting, and internal fixation. Journal of Bone & Joint Surgery 1982; 64A: 1164–78.

7. Malone KJ, Magnell TD, Freeman DC, et al. Surgical correction of dorsally angulated distal radius malunions with fixed angle volar plating: a case series. Journal of Hand Surgery American Volume 2006; 31(3): 366–72.

8. Orbay JL, Diego L, Fernandez DL. Volar fixation for dorsally displaced fractures of the distal radius: a preliminary report. Journal of Hand Surgery American Volume 2002; 27A(2): 205–15.

9. Lozano-Calderon SA, Souer S, Mudgal C et al. Wrist mobilization following volar plate fixation of fractures of the distal part of the radius. Journal of Bone & Joint Surgery 2008; 90(6): 1297–304.

10. Souer JS, Buijze G, Ring D. A prospective randomized controlled trial comparing occupational therapy with independent exercises after volar plate fixation of a fracture of the distal part of the radius. Journal of Bone & Joint Surgery America 2011; 93(October (19)): 1761–6.

12345678910111213

Chapter 10The Darrach procedure for post-traumatic

reconstruction

Chapter 10

136

P.B. De Witte, M. Wijffels, J.B. Jupiter, D. Ring

Acta Orthopaedica Belgica 2009;75(3):316-22

ABSTRACT

Over a 6-year-period, 15 women and 11 men with a mean age of 53 years (range, 24 to 80 years) had resection of the distal part of the ulna (Darrach’s procedure) to address stiffness, instability, non-union, or substantial radioulnar length discrepancy after trauma. At an average follow-up of 21 months (range,4 to 60 months), the improvement in total arc of forearm rotation averaged 87° (range, 0° to 160°), from an average of 49° to an average of 136° (p <0.001). The proportion of patients with occasional or continuous pain after the Darrach procedure (7 after vs. 16 prior; p = 0.04) was significantly reduced. Only two patients had reoperation related to the residual ulna.

In this study, the Darrach procedure improved fore-arm rotation and pain in patients with posttraumatic stiffness, instability, non-union, or substantial radioulnar length discrepancy with a low complication and re-operation rate.

137

The Darrach procedure for post-traumatic reconstruction

10

INTRODUCTION

Resection of the distal ulna as credited to Darrach7,19 may be considered for patients with dysfunction of the distal radial ulnar joint (DRUJ) resulting from trauma, inflammatory arthritis, or congenital deformities. In patients with post-traumatic DRUJ dysfunction, the indications for the Darrach procedure include pain, instability, and limited range of forearm motion. Most studies have reported satisfactory results of the Darrach proce-dure, with marked improvement in pain relief and range of movement, and minimal loss of grip strength.1,5,8,14,17,22,25-27 However, the Darrach procedure has fallen out of favour recently as a result of publications that reported failure of pain relief and poor outcome in some patients.2,3,9,12,13,23,24

Persistent pain after the Darrach procedure has been ascribed to instability of the ul-nar stump, with or without impingement of the ulnar stump on the radius as described by Bell et al.2 Concern regarding ulnar stump instability has greatly reduced the appeal of the Darrach procedure to the point that many surgeons seem reluctant to consider this procedure nowadays. Reported alternatives for DRUJ reconstruction include the Sauve-Kapandji procedure16, partial resection of the distal ulna as described by Watson28 or Bowers4, an ulna diaphyseal shortening osteotomy6, a distal ulna wafer resection10, or ulnar head replacement15, but all of these procedures have mixed results11,13,18,21,24 and the optimal treatment for DRUJ dysfunction remains uncertain and debatable.

An argument can be made that Darrach resection of the distal ulna is the simplest and one of the most predictable ways to address complex post-traumatic DRUJ dysfunction including stiffness, instability, substantial radioulnar length discrepancy, or non-union of the distal ulna. It can also be argued that the primary perceived failure of the Darrach procedure is in pain relief, which remains the most challenging and unpredictable of indications at any anatomical site. Our hypothesis was that when the Darrach procedure is used not solely for pain relief, but rather primarily to gain forearm mobility or to ad-dress distal radioulnar dislocation, distal ulnar non-union, or severe radioulnar length discrepancy, it relatively predictably achieves these goals without a substantial risk of disabling pain or re-operation.

mATERIAL AND mETHODS

Between 2000 and 2006, two surgeons performed the Darrach procedure in 66 patients. During this period only 7 patients had alternative procedures for DRUJ dysfunction (2 hemi-resection arthroplasties, 2 Sauvé-Kapandji procedures, 1 distal ulna wafer resec-tion, 1 Darrach procedure combined with a extensor carpi ulnaris stabilization, and 1 ulnar head prosthesis). We were interested in adult patients in whom Darrach’s resection

Chapter 10

138

of the distal ulna was performed for post-traumatic reconstruction to treat stiffness, in-stability, non-union of the ulna or prior Sauvé-Kapandji procedure, or substantial radio-ulnar length discrepancy in the setting of a complex post-traumatic skeletal deformity of the radius (non-union, mal-union, or radiocarpal arthritis), greater than 4 months after the original injury. We excluded patients under age 18 (1 patient), patients in whom the Darrach procedure was performed for the sequelae of rheumatoid arthritis (9 patients), for problems arising from other non-traumatic illnesses (tumour, burn, or compartment syndrome; 7 patients), when the Darrach procedure was part of the management of an acute traumatic injury (within 4 months of injury; 6 patients), and in post-traumatic patients for whom the primary indication for surgery was pain relief (10 patients), and patients with fewer than 4 months follow-up after the Darrach procedure that we were unable to contact (7 patients), leaving a cohort of 26 patients satisfying the inclusion and exclusion criteria.

Using an Institutional Review Board approved protocol, we reviewed the medical records of these 26 patients and invited patients with fewer than 12 months follow-up to return for a free evaluation. Six patients had a specific research evaluation by an investigator not involved in the care of the patients an average of 37 months (range, 11 to 60 months) after the index procedure. The mean follow-up in these 26 patients was 21 months (range, 4 to 60 months). Among these 26 patients there were 15 women and 11 men with a mean age of 53 years (range, 24 to 80 years) at the time of surgery. On average, the Darrach procedure was performed 18 months (range, 4 to 127 months) after the original injury.

The original traumatic injury was a fracture of the distal radius in 21 patients, diaphy-seal fractures of the radius and ulna in 2 patients, two posterior olecranon fracture-dislo-cations of the elbow (one with ipsilateral transcaphoid perilunate fracture dislocation), and a crush injury with hand fractures but no forearm fractures in 1 patient. The initial treatment was operative in 23 patients and non-operative in 3 patients. An average of 1.4 surgeries (range 0 to 3) was performed prior to the index Darrach procedure. Two patients had a wrist arthrodesis to address radiocarpal arthritis at the time of the Dar-rach procedure.

Indications

The indication for Darrach’s procedure was severe restriction of forearm rotation in 16 patients, substantial radioulnar length discrepancy in the setting of an ununited fracture of the radius treated simultaneously in 5 patients (4 distal radius, and one radial diaphy-sis), chronic instability of the distal radioulnar joint in 2 patients, non-union of a fracture or osteotomy of the ulna in 2 patients, and an ununited Sauvé-Kapandji procedure in 1 patient (Figures 10.1 and 10.2). Three of the patients treated for stiffness had concomi-tant release of a proximal radioulnar synostosis related to an associated elbow injury.

139


10

These were performed concurrently with the Darrach procedure in 2 patients, and 5 months before the Darrach procedure in 1 patient. Two patients had a wrist arthrodesis to address radiocarpal arthritis at the time of the Darrach procedure.

Evaluation

An investigator not involved in the initial care of the patients evaluated pre-operative and latest follow-up wrist flexion and extension, forearm rotation, and pain status from the medical records. Standard posteroanterior and lateral radiographs were evaluated for signs of chronic radioulnar impingement defined by a mark or groove on the distal radius.

The 6 patients that returned for a research-specific evaluation had a specific radio-graphic evaluation including standard posteroanterior and lateral radiographs, and stress-loaded (patient holding a 2.5-kg weight) posteroanterior radiographs with the shoulder at the side, the elbow flexed at 90°, and the forearm in neutral rotation.20 The stress-loaded radiographs were used in order to evaluate signs of radiographic dynamic radioulnar convergence, as reported by McKee and Richards.23 The minimum distance between ulnar stump and radial shaft was measured and compared in resting and stress-loaded radiographs. A smaller radioulnar distance in stress-loaded radiographs

Figure 10.1. A 32-year-old man with long standing malunion of the radius and distal radioulnar joint insta-bility presented with complaints of pain and supination limited to 10°.a: An oblique radiograph shows the malunion and malalignment of the distal radioulnar joint.b: After Darrach resection of the distal ulna, his pain was resolved and he had full forearm rotation.

Chapter 10

140

represents “dynamic radioulnar convergence”, signs of actual contact between the bones was described as radioulnar impingement.

Pre-operative evaluation

Prior to the index Darrach resection of the distal ulna, the average arc of wrist flexion and extension was 55° (range, 20° to 140°) with an average flexion of 29° (range, 10° to 70°) and an average extension of 26° (range, 0° to 70°). In three patients with severe instability of a non-united fracture of the distal radius, it was not possible to measure wrist flexion arc.

The average arc of forearm rotation was 49° (range, 0°to 160°), with an average prona-tion of 30° (range, 0° to 80°) and an average supination of 19° (range, 0° to 80°). There were 24 patients with a forearm arc of rotation 100° or less, 3 of whom had concomitant proximal radioulnar synostosis. Six patients had rest pain, 10 reported pain with some

Figure 10.2. A 65-year-old woman had a non-union of her ulna after an ulnar shortening osteotomy and 2 subsequent surgeries to try to gain union.a and b: Posteroanterior and lateral radiographs after removal of the distal part of the ulna. Her pain was resolved and function fully restored.

141


10

activities of daily living, and 9 patients had no pain before the Darrach procedure. In one patient, pain status was not recorded.


We compared pre-operative data to data at the latest post-operative follow-up moment. For continuous data (range of motion) a paired t-test was used. Categorical data (pain-score) were evaluated using McNemar’s test. P-values of less than 0.05 were considered statistically significant.

RESULTS

Complications and subsequent surgery

One patient with residual pain had a second procedure to remove bony protuberances from the ulnar stump, combined with an extensor carpi ulnaris tenodesis. One patient had radioulnar impingement related to malunion of the radius that resolved with radial osteotomy. One patient had removal of a distal radius plate and another had revision of a hypertrophic scar.

Final evaluation

Patients were evaluated an average of 21 months (range, 4 to 60 months) after the index Darrach procedure and after all subsequent surgeries. Seven patients reported pain during activities of daily living. Nineteen patients reported no complaints of pain at all. One patient had occasional non-painful clicking with forearm rotation, but no radiographic signs of radioulnar impingement. Excluding the 2 patients that had a wrist arthrodesis, the average arc of wrist flexion and extension was 83° (range, 30° to 140°) with an average flexion of 42° (range, 5° to 70°) and an average extension of 41° (range, 10° to 70°). The average arc of forearm rotation was 136° (range, 20° to 160°), with an average pronation of 71° (range, 10° to 80°) and an average supination of 65° (range, 10° to 80°). At the final evaluation after the Darrach procedure, there were only 3 patients with an arc of forearm rotation less than 100°, and 2 of these 3 patients were also treated for a proximal radioulnar synostosis. In 2 patients (8%), there were radiographic signs of contact between the ulna and radius, defined by a mark or groove on the distal radius. Neither patient reported pain or clicking.

Comparison of pre-operative and final evaluation

The improvement in total arc of forearm rotation averaged 87° (range, 0° to 160°; from an average of 49° to an average of 136° (p < 0.001) with an average improvement in supination of 46° (range, 0° to 80°; from an average of 19° to an average of 65° (p < 0.001)

Chapter 10

142

and an average improvement in pronation of 41° (range, 0° to 80°; from an average of 30°to an average of 71° (p <0.001).

Excluding patients with severe pre-operative instability and patients treated with ar-throdesis, the average improvement in total wrist flexion-extension arc was 23° (range, −15° to 90°), from an average of 58° to an average of 81° (p = 0.004), with an average improvement in wrist flexion of 11° (range, −5° to 45°, from an average of 30° to an average of 41°, (p = 0.004) and an average improvement in wrist extension of 12° (range, −20° to 55°, from an average of 28° to an average of 40° (p =0.01).

The number of patients with occasional or continuous pain after the Darrach proce-dure (7 after vs. 15 prior; p = 0.04) was significantly reduced.

Research-related follow-up visit

The average DASH-score of the six patients that returned for a research-specific evalua-tion was 30.6 points (range, 3 to 68 points). None of these 6 patients reported rest pain or clicking. On radiographic evaluation 5 of the 6 patients had some dynamic radioulnar convergence (average of 8.4 mm; range, 2.5 to 13.3 mm) and one patient had a larger radioulnar distance on the stress- loaded radiograph (−2.1 mm, from 0.7 to 2.8 mm). In one patient, there was evidence for chronic radioulnar impingement, defined by groov-ing on the radius on standard radiographs. Additionally, two patients without signs of impingement on standard radiographs demonstrated radioulnar contact on the stress-loaded radiograph.

DISCUSSION

Our results suggest that Darrach’s resection of the distal ulna is a useful procedure for patients with posttraumatic forearm stiffness or instability, or substantial radioulnar length discrepancy in the setting of a complex reconstructive procedure. In particular, the Darrach procedure achieved substantial gains in forearm rotation in our patients.

Very few patients had a groove on the radius as evidence of convergence. Most patients in whom stress radiographs were obtained had some dynamic radioulnar convergence. Nonetheless, pain was uncommon and not clearly related to radioulnar convergence, either dynamic or with a groove on radiographs.

Several reports document the utility of the Darrach procedure, describing consistent improvement in range of motion, diminished pain in most patients, and no instances of increased disability.1,5,8,17,22 Others have not been as satisfied.2,3,9,12,13,23,24 For instance, Bieber et al documented persistent complaints of pain, limitation of motion, snapping, or weakness in 20 of 288 patients (7%) treated with the Darrach procedure3, a rate that might be considered acceptable in the treatment of complex reconstructive problems.

143


10

More striking is the report of Ekenstam et al. that 12 of 24 (50%) patients treated with the Darrach procedure after fracture of the distal radius rated themselves as not improved. Range of motion improved in 75% of patients, and none had a worse range of motion. Pain was unchanged in 54% and improved in 33%. Of the 13 patients with a relatively normal DRUJ alignment, only 4 (31%) were satisfied with the procedure.9 This supports our opinion that the Darrach procedure is most useful when there is a discrete, objective problem at the DRUJ with associated impairment of forearm rotation, where the potential benefit of resection of the distal ulna is clear, in contrast with surgery where the primary indication is pain relief and the anatomy is relatively preserved.

Both George et al. and Minami et al. compared the Darrach procedure to the Sauvé-Kapandji (SK) procedure retrospectively and found relatively comparable results.13,24 Both procedures have the potential disadvantage of symptomatic instability of the ulnar stump, the most severe type of which results in impingement of the ulnar stump on the radius. Reports such as that of Bell et al. describing 10 patients referred for painful impingement between the ulnar stump and the radius after a Darrach procedure2 have increased our concern about potential radioulnar impingement.

On the other hand the report of McKee and Richards was more reassuring, identifying dynamic radioulnar convergence in 14 of 25 patients that had a Darrach procedure for posttraumatic complications23, but no correlation between convergence and Gartland and Werley wrist scores. In 5 of their patients, the radius and ulna demonstrated actual contact on radiographs, but only 2 of these patients had pain.

Our study is consistent with that of McKee and Richards.23 Radioulnar impingement was uncommon and inconsistently symptomatic. The same was true for dynamic radio-ulnar convergence, although we evaluated this in a very small subset of patients. Only two patients (8%) had surgery to address residual symptoms at the distal radioulnar joint, and one of these patients had osteotomy of a malunited radius.

The weaknesses of our study are common to most studies of DRUJ reconstruction, including the relatively small patient cohort, the fact there was no control group, the relatively short follow-up period, and the lack of specific radiographic tests in all patients. Our patients had complex problems and often had concomitant procedures, which would be expected to be detrimental to our results. Since our aim was to reinforce that Darrach’s procedure can be useful for complex post-traumatic forearm impairment, we believe that our results reflect what patients and surgeons should expect.

We chose to exclude the ten patients treated during the study period that had limited impairment and relatively preserved anatomy in whom the primary indication for the Darrach procedure was pain relief rather than stiffness, non-union, instability, or length discrepancy. Ten patients is too few to make any meaningful comparisons.

Keeping these limitations in mind, we believe that our retrospective case series sup-ports the use of the Darrach procedure for patients with discrete problems (stiffness,

Chapter 10

144

instability, non-union, and marked radioulnar length discrepancy) that are clearly re-lated to distorted anatomy at the distal radioulnar joint. Until more definitive, controlled data are produced, our experience would suggest that the problems related to dynamic convergence and radioulnar impingement after Darrach’s procedure are probably an acceptable tradeoff for the diminished impairment achieved in these complex post-traumatic forearm problems.

REFERENCES

1. Albert S, Wohl M, Rechtman A. Treatment of the disrupted radio-ulnar joint. J Bone Joint Surg 1963; 45-A: 1373-81.

2. Bell M, Hill R, McMurtry R. Ulnar impingement syndrome. J Bone Joint Surg 1985; 67-B: 126-9. 3. Bieber E, Linscheid R, Dobyns J, Beckenbaugh R.Failed distal ulna resections. J Hand Surg 1988;

13-A: 193-200. 4. Bowers W. Distal radioulnar joint arthroplasty: the hemiresection-interposition technique. J Hand

Surg 1985; 10-A: 169-78. 5. Boyd H, Stone M. Resection of the distal end of the ulna. J Bone Joint Surg 1944; 26: 313-21. 6. Chun S, Palmer A. The ulnar impaction syndrome: follow-up of ulnar shortening osteotomy. J

Hand Surg 1993; 18-A: 46-53. 7. Darrach W. Anterior dislocation of the head of the ulna. Ann Surg 1912; 56: 802-3. 8. Dingman P. Resection of the distal end of the ulna (Darrach operation); an end result. J Bone Joint

Surg 1952; 34-A: 893-900. 9. Ekenstam F, Engkvist O, Wadin K. Results from resection of the distal end of the ulna after frac-

tures of the lower end of the radius. Scand J Plast Reconstr Surg 1982; 16: 177-81. 10. Feldon P, Terrono A, Belsky M. The “wafer” procedure. Partial distal ulnar resection. Clin Orthop

1992; 275: 124-9. 11. Fernandez D, Joneschild E, Abella D. Treatment of failed Sauve-Kapandji procedures with a

spherical ulnar head prosthesis. Clin Orthop 2006; 445: 100-7. 12. Field J, Majkowski R, Leslie I. Poor results of Darrach’s procedure after wrist injuries. J Bone Joint

Surg 1993; 75- B: 53-7. 13. George M, Kiefhaber T, Stern P. The Sauve-Kapandji procedure and the Darrach procedure for

distal radio-ulnar joint dysfunction after Colles’ fracture. J Hand Surg 2004; 29-B: 608-13. 14. Hartz C, Beckenbaugh R. Long-term results of resection of the distal ulna for post-traumatic

conditions. J Trauma 1979; 19: 219-26. 15. Herbert T, van Schoonhoven J. Ulnar head replacement. Tech Hand Up Extrem Surg 2007; 11:

98-108. 16. Kapandji I. The Kapandji-Sauve operation. Its techniques and indications in non rheumatoid

diseases. Ann Chir Main 1986; 5: 181-93. 17. Kessler I, Hecht O. Present application of the Darrach procedure. Clin Orthop 1970; 72: 254-60. 18. Kobayashi A, Futami T, Tadano I et al. Radiographic comparative evaluation of the Sauve-Kapandji

procedure and the Darrach procedure for rheumatoid wrist reconstruction. Mod Rheumatol 2005; 15: 187-90.

145


10

19. Lau F, Chung K. William Darrach, MD: his life and his contribution to hand surgery. J Hand Surg 2006; 31-A: 1056-60.

20. Lees VC, Scheker LR. The radiological demonstration of dynamic ulnar impingement J Hand Surg 1997; 22-B: 448-50.

21. Lichtman D, Ganocy T, Kim D. The indications for and techniques and outcomes of ablative procedures of the distal ulna. The Darrach resection, hemiresection, matched resection, and Sauve-Kapandji procedure. Hand Clin 1998; 14: 265-77.

22. Lugnegard H. Resection of the head of the ulna in posttraumatic dysfunction of the distal radio-ulnar joint. Scand J Plast Reconstr Surg 1969; 3: 65-9.

23. McKee M, Richards R. Dynamic radio-ulnar convergence after the Darrach procedure. J Bone Joint Surg 1996; 78: 413-18.

24. Minami A, Iwasaki N, Ishikawa J et al. Treatments of osteoarthritis of the distal radioulnar joint: long-term results of three procedures. Hand Surg 2005; 10: 243-8.

25. Shearman C. The long-term outcome following Darrach’s procedure for complications of fractures of the distal radius. Injury 1988; 19: 318-20.

26. Sotereanos D, Leit M. A modified Darrach procedure for treatment of the painful distal radioulnar joint. Clin Orthop 1996; 325: 140-7.

27. Tulipan D, Eaton R, Eberhart R. The Darrach procedure defended: technique redefined and long-term follow-up. J Hand Surg 1991; 16-A: 438-44.

28. Watson H, Gabuzda G. Matched distal ulna resection for posttraumatic disorders of the distal radioulnar joint. J Hand Surg 1992; 17-A: 724-30.

12345678910111213

Part vGeneral discussion and summary

12345678910111213

Chapter 11General discussion and future perspectives

151

General discussion and future perspectives

11

GENERAL DISCUSSION

Distal radius injuries are common and may be complicated by long lasting wrist pain. Distal radioulnar joint injury (DRUJ) and subsequent instability should not be over-looked in the search for the causal factors of pain. Instability results from imbalance in the complex stabilizing system around the DRUJ, caused by the injury of the wrist. Typi-cally, these injuries concern distal radius fractures, with or without ulnar styloid process fractures. Various fracture characteristics have proven to influence the DRUJ stability. The triangular fibrocartilage complex (TFCC), with its collaborating radioulnar fibers, has been assumed to be the principal stabilizer of the DRUJ.1-5 However, more recently, it has been suggested that the distal oblique bundle, located distally in the interosseous membrane, also fulfills an important stabilizing role.6,7 Defining the principal DRUJ sta-bilizer may help in the treatment of DRUJ instability. Most of the research in this thesis relates to the principal DRUJ stabilizer: its injury results in posttraumatic joint changes and may influence clinical outcome, and its instability poses a diagnostic challenge in many ways.

CLINICAL TESTING

Although DRUJ instability seems to be a common injury, its diagnosis has proven to be a challenge. To confirm the diagnosis several clinical tests have been suggested8-16, but their predictive values are very low and the use of these tests therefore remains a topic of discussion. Generally accepted and most used in studies is the stress test, developed to test the deep radioulnar ligaments of the TFCC. DRUJ instability is tested positive if the forced dorsopalmar translation of the radius in the injured wrist, with respect to sta-bilized ulna, is more than in the uninjured wrist. The radius pull test14, developed to test the interosseous membrane, provokes longitudinal movement between ulna and radius and has a sensitivity and specificity up to 100% in cadaveric studies. A major downside of this test is the need for it to be performed under regional or general anesthesia and the lack of data on reliability in the clinical situation. The clunk test8, the extensor carpi ulnaris (ECU) test15 and press test16 are described to examine DRUJ instability in non-anesthetized patients. All three have their specific shortcomings. Their reliability and predictive value have not been determined yet.

There are multiple potential explanations for the absence of a reliable and predictive clinical test to assess DRUJ instability. First, there is no gold standard for the determi-nation of DRUJ instability, which means that the mentioned tests cannot be reliably analyzed for their predictive value. Second, DRUJ instability depends on several ana-tomic structures. The described clinical tests cannot be used to differentiate between

Chapter 11

152

individual stabilizing structures in a symptomatic wrist. Third, great variation exists in physiological DRUJ translation in the uninjured wrist, which renders the interpretation of test findings difficult and results in varying inter-observer results.

A valid clinical test for diagnosing DRUJ stability should provide characteristics that overcome the afore mentioned shortcomings. First, in order to correct for the wide physiological range in DRUJ translation, the test results of the injured wrist should be related to those of the uninjured side. Second, the test should analyze individual stabi-lizing anatomical structures separately, as far as possible, which needs, if the risks can be clinically justified, local or general anesthesia. Third, the test should also be performed under the image intensifier, in order to visualize and quantify the amount of pathologi-cal ulnar translation in the longitudinal and/or volar and dorsal direction.

For daily practice this means that, the existing tests should be optimized wherever possible. DRUJ laxity is best evaluated when the currently known tests are combined and carried out under optimal circumstances: the radius pull test, the clunk test and stress test should be carried out under the image intensifier by experienced and well trained physicians. The radius pull test should be carried out with the wrist in neutral position to correct for tensioned TFCC ligaments. The clunk test should be carried out during pronation and supination to evaluate for a painful clicking movement that can be seen or felt. The stress test should be performed in various positions to test accord-ingly radioulnar ligaments of the TFCC. The extensor carpi ulnaris (ECU) test has to be carried out to test the sixth dorsal compartment. Although demanding and potentially requesting the support of anesthesiologists, this investigation may be of great value to the symptomatic patient recovering from a distal radius fracture with potential DRUJ instability.

This thesis shows that DRUJ instability after long term follow up, diagnosed with the nowadays commonly used tests, is found in 1 out of 3 patients with conservatively treated, consolidated distal radius fracture. With regard to wrist function (except from flexion), pain, strength and patient reported outcomes no differences were found be-tween 17 patients with and 32 without DRUJ instability. These findings are contrary to results published by Lindau and colleagues.10 In their study, 76 patients younger than the age at which osteoarthritis normally presents, were evaluated for DRUJ instability after a mean follow-up of 26 months. Sixty-one distal radius fracture patients had been treated conservatively and 15 patients had been operated at least once. DRUJ instability was tested by the stress test executed by one clinician. Significantly worse outcomes with regards to subjective wrist score and pain were found in the 17 patients with clinically confirmed DRUJ instability. The differences between Lindau’s study and our findings are difficult to explain. The age of the investigated patients may be of principal importance. Lindau studied younger patients, median age 41 years, compared to the median age of 61 years in our study. In older patients, arthritic changes resulting in wrist pain may mask

153


11

the complaints of DRUJ instability, especially when the wrist demands are less, as can be expected in the elderly. The role of the surgically treated patients in Lindau’s study remains unclear, since the results were not reported separately for the conservatively and operatively treated patients. Iatrogenic, postsurgical adhesions and scar tissue, may have influenced the outcome, although operatively treated, initially unstable distal radius fractures are found to have a similar outcome, or even better, then conservatively treated ones.17,18 A more likely reason for the differences between the two studies is the way clinical DRUJ instability was diagnosed. Lindau used the stress test solely, whereas we used the clunk test additionally. In both studies, instability was found in about 1 out of 3 patients. In our results, in the DRUJ unstable patients, only 6 patients had positive findings for both tests. This poor agreement between tests also demonstrates the poor testing characteristics, and clearly demonstrates the risk of comparing groups defined by coincidence, rather than by a validated difference in clinical findings.

RADIOLOGICAL ASPECTS

When clinical investigations are inconclusive or unreliable, radiological investigations may aid in diagnosing DRUJ instability. Conventional radiographs of the wrist can reveal direct and indirect signs of DRUJ instability, but they have their shortcomings; obtain-ing true lateral views is difficult and the static radiographs do not depict the dynamic process of DRUJ movement.19-23 Computed tomography can partially overcome the limi-tations of radiographs and provide more detailed information on the osseous anatomy. In part II of this thesis, the additional diagnostic value of CT-scanning in wrist injuries was evaluated. Additional CT-scan of the wrist did not improve the fair inter-observer agreement in diagnosing a coronal lunate facet fracture on radiographs. This finding suggests a limited role for additional CT-scans over standard radiographs to evaluate for fracture involvement of the DRUJ. Rozental and colleagues proved, among others, CT-scan to be superior for quantifying articular discongruencies in the lunate facet.24,25 In general, CT-scan may be helpful in pre-operative planning, suggesting some role for CT-scan in the treatment of distal radius fractures.

Magnetic resonance imaging has greater sensitivity for soft tissue contrast compared to CT. High-resolution MRI seems to diagnose TFCC tears with high accuracy, and may therefore be useful in diagnosing DRUJ instability.26,27 Scientific evidence is scarce, but some data suggest a discriminating role in abnormal symptomatic DRUJ geometry.28 As in CT, the relation between MR findings and clinical relevance remains undefined.

In this thesis the reliability of wrist CT-scan, as determined by inter- and intraobserver agreement in DRUJ translation, of four DRUJ instability scoring systems was tested. The Epicenter Method showed the best reliability with a moderate interobserver agreement.

Chapter 11

154

Unfortunately, the inter observer agreement does not tell us much about the accuracy of the CT for determination of DRUJ instability presence, since a good gold standard to compare the CT findings to, is lacking. In the absence of a gold standard, defining the normal physiological ranges of DRUJ translation in the uninjured wrist on CT, may help to determine guidelines for the diagnosis of DRUJ instability. Only a few studies have published on normal CT ranges of DRUJ motion in the uninjured wrist based on living subjects.23,29,30 Nakamura et al considered volar or dorsal dislocation during rotation of less than 25% of the sigmoid notch diameter as normal and modified the radio ulnar line method, based on findings in 37 healthy wrists. Lo and colleagues present the new radioulnar ratio technique to evaluate ulnar head translation, based on normal findings in 13 healthy wrists compared to cadaveric specimens and rheumatoid arthritic patients. Park et al. based normal values on 45 uninjured wrists. Given the variety in methodology and included patients in these three studies, it is not surprising that normal values docu-mented so far, varied widely. This reflects the need for a study with accurate representa-tion of the trauma population, stratification for various ethnicities and ages, and with standardized scoring techniques by several observers, to obtain useful date for normal physiological ranges in DRUJ instability.

Defining normal ranges includes the risk of unintentional incorrect treatment; a wide range of normal values will lead to under-treatment, since CT-findings will be easily interpreted as normal, and thus potentially as false negative. In contrast, the establish-ment of a small normal range of DRUJ motion would lead to over-treatment.

The normal ranges are determined using the uninjured wrist and rely on the assump-tion that symmetry in DRUJ translation exists within one person. This however, has never been evaluated, but static radiological findings may differ between left and right.31 To investigate the symmetry, a protocol should include many individuals in which DRUJ translation is evaluated in two uninjured wrists. If symmetrical DRUJ translation is present, proportional individual pathological values of instability can be defined. Ad-ditionally, such a study should evaluate the relationship between CT-findings in a wrist clinically diagnosed with DRUJ instability and the contralateral uninjured wrist, for each individual. This implies the presence of a valid test to diagnose DRUJ instability, which has proven to be consistently difficult.

TREATmENT OF DISTAL RADIUS FRACTURES

Conservative treatment of a distal radius fracture is not straightforward; follow-up should be on a regular base and (adjustments in) casting the fracture needs knowledge of the specific fracture patterns and characteristics. For example, as described in Chapter 5, distal radius fractures with an accompanying fractured ulnar styloid tend to show more

155


11

secondary dislocation compared to fractures without. To evaluate this re-dislocation of the fracture a second visit including radiographs is advocated. Dependent on patient characteristics in combination with fracture dislocation the intended conservative treat-ment may need change to a more invasive one focusing on reduction and stabilization. An interesting fact is that the most recent Dutch guideline for treatment of distal radius fractures (2010) did not include a follow-up schedule for distal radius fractures.32

Since quality of care, outcome and complication rates are hot topics in the society, in politics, for health care insurance companies and are often subject of lawsuits, dedicated wrist teams have to be formed. Treatment of distal radius fractures, and even more its complications, has shown to involve its complex soft tissues as well, therefor thorough knowledge of the complete anatomy of the wrist is needed. Chapter 3 shows that treat-ing an increased number of distal radius fractures per timeframe and specialization in the field results in more consistency in the evaluation of fractures. Although not directly evidence based, an increased number of treated distal radius fractures per physician, may lead to better outcome. Ideally, specialized multidisciplinary teams should treat distal radius fractures. The leading physician may have the background of a trauma, orthopedic- or plastic surgeon as long as he or she treats distal radius on a regular base, in which a minimum number of wrist operations performed per surgeon per year will best be defined by consensus of the experts.33

The radiologist of the multi-disciplinary wrist team should be familiar with most recent imaging techniques and different modalities, especially when it comes to the evaluation of complications. Postoperative care should include physiotherapeuthical advice to diminish postoperative pain.34

TREATmENT OF DRUJ INSTABILITY

After consolidation of a distal radius fracture, the presence of DRUJ instability has been identified as an independent worsening factor for outcome with regard to subjective and objective wrist score and pain.10 In patients with chronic symptomatic DRUJ insta-bility a treatment algorithm should enclose correction of osseous malalignment.11,35 Only when anatomical positioning of the fractured bone is achieved, the biomechanics of the collaborating stabilizing structures can be optimized. Malalignment of the sig-moid notch and ulnar fovea may result in unstable and painful discongruency of the DRUJ.36,37 Depending on the position of the malaligned distal radius, the volar or dorsal radioulnar ligaments of the TFCC may become lax and lose their stabilizing function.38 Residual ulnar translation of the radial shaft may introduce laxity of the distal interosse-ous membrane, with its distal oblique bundle39 resulting in DRUJ laxity.40 In Chapter 10, a new surgical approach to correct partially healed, malaligned distal radius fractures

Chapter 11

156

is presented. Although not studied in DRUJ unstable patients specifically, the outcome after this extended flexor carpi radialis approach followed by volar plating, has proven to be safe and effective as a treatment method for nascent malunions of the distal radius.

If the instability persists, despite anatomic osseous reconstruction, the stabilizing soft tissues should be repaired. When primary soft tissue repair is impossible, many reconstructional techniques have been described to replace the failing stabilizers. Last resort salvage-procedures or joint replacing techniques should be carried out if invali-dating DRUJ instability persists. These very specific surgical procedures, involving the anatomical structures of the wrist, again call for dedicated expertise in this field. Future treatment of DRUJ injuries may comprise of both clinical and radiological evaluation, as well as conservative or surgical treatment followed by rehabilitation, coordinated from a multidisciplinary dedicated wrist team.

WHAT CAN BE LEARNED FROm THIS THESIS

The various questions stated in Chapter 1 can now be answered, based on the results of this thesis.• CT-scan,inadditiontoconventionalradiographs,doesnotimprovetheinterobserver

agreement on diagnosing coronal articular distal radius fractures compared to just the radiographs.

• CT-scan, in addition to conventional radiographs, does not improve the interob-server agreement on the determination of fracture instability in coronal lunate facet fractures, compared to just radiographs

• The number of operatively treated distal radius fractures has a positive effect oninterobserver agreement on determination of instability of a coronal lunate facet fracture. The background of observers influences the interobserver agreement on presence and instability of coronal lunate facet fractures

• TheEpicentermethod is themost reliablemethod for thedeterminationofDRUJinstability using CT-scans of the wrist.

• UsingtheEpicentermethodinsupination,interobserveragreementissignificantlybetter in injured wrists compared to uninjured wrists. Using the Radioulnar line method intraobserver agreement is significantly better in injured wrists compared to uninjured wrists.

• ThereislargenormalvariationinnormalDRUjointmovement• In thepresenceof anUSF secondarydislocation ismore frequent indistal radius

fractures with an accompanying USF compared to distal radius fractures without an accompanying USF

157


11

• Non-unionofanulnarstyloidbasefracturedoesnotcompromisetheoutcomeofoperatively treated distal radius fractures compared to outcome after union of the ulnar styloid base fracture in operatively treated distal radius fractures.

• Nodifferenceinoutcomeofdistalradiusfractureswithorwithoutnon-unionofanulnar styloid can be found.

• ClinicalDRUJ instabilitydoesnot influence the clinicaloutcomeof conservativelytreated distal radius fractures after long-term follow-up, despite significantly better flexion in the DRUJ unstable patients.

• TheDarrachprocedureiseffectiveinregainingforearmmobilityafter,amongstoth-ers, symptomatic posttraumatic DRUJ changes.

• Theextendedflexorcarpiradialisapproachfollowedbyvolarplatingisasafeandef-fective procedure to correct partially healed malaligned fractures of the distal radius.

What can be learned from this thesis is that the anatomy around the distal radius is com-plex and is obviously influenced by a distal radius fracture. The ongoing discussion on the influence of ulnar styloid fractures on the outcome of distal radius fractures comes to an end. Although it seems to promote secondary dislocation, based on the highest level of evidence it can be stated that an ulnar styloid fracture should not be a surgical target since it does not influence outcome of distal radius fractures, even if it results in a non-union. One of the complicating factors after distal radius treatment is DRUJ instability. In conservatively treated fractures, the influence of DRUJ instability on out-come is limited. The ultimate question remains how to reliably and accurately diagnose DRUJ instability. Accurate clinical tests still need to be developed; CT-scan based scores seem reliable but less is known on their validity and normal values vary widely. When, despite the diagnostic dilemma, DRUJ instability is diagnosed, treatment should start with correction of osseous malalignment, in which the extended flexor carpi radialis ap-proach has shown safe and effective. In the absence of distal radius malunion, anatomic or non-anatomic reconstruction of the DRUJ stabilizing structures can be carried out. If still unsuccessful, salvage procedures are optional.

REFERENCES

1. Ekenstam F, Hagert CG. Anatomical studies on the geometry and stability of the distal radio ulnar joint. Scand J Plast Reconstr Surg 1985; (1): 17-25.

2. Hagert CG. Distal radius fracture and the distal radioulnar joint - anatomical considerations. Handchir Mikrochir Plast Chir 1994; 26(1): 22-6.

3. Schuind F, An KN, Berglund L, et al. The distal radioulnar ligaments: a biomechanical study. J Hand Surg Am 1991; 16(6): 1106-14.

Chapter 11

158

4. Moritomo H. The distal interosseous membrane: current concepts in wrist anatomy and biome-chanics. J Hand Surg am. 2012; 37(7): 1501-07

5. Kihara H, Shorts WH, Werner FW et al. The stabilizing mechanism of the distal radioulnar joint during pronation and supination. J Hand Surg Am. 1995; 20(6): 930-36

6. Kitamura T, Moritomo H, Arimitsu S, et al. The biomechanical effect of the distal interosseous membrane on distal radioulnar joint stability; a preliminary anatomic study. J Hand Surg am. 2011; 36(10): 1626-30

7. Dy CJ, Jang E, Taylor SA et al. The impact of coronal alignment of distal radioulnar joint stability following distal radius fracture. J Hand Surg Am. 2014; 39(7): 1264-72

8. Jupiter JB. Commentary: The effect of ulnar styloid fractures on patient-rated outcomes after volar locking plating of distal radius fractures. J Hand Surg Am 2009; 34(9): 1603-4.

9. Kim JP, Park MJ. assessment of distal radioulnar joint instability after distal radius fracture: com-parison of computed tomography and clinical examination results. J Hand Surg Am 2008; 33(9): 1486-94.

10. Lindau T, Hagbert L, Aldercreutz C et al. Distal radioulnar instability is an independent worsening factor in distal radial fractures. Clin Orthop Relat Res 2000; 376: 229-35.

11. Szabo RM. Distal radioulnar joint instability. J Bone Joint Surg Am 2006; 88(4): 884-94. 12. Davidson PA, Moseley JB Jr., Trullos HS. Radial head fracture. A potentially complex injury. Clin

Orthop Relat Res 1993; 297: 224-30. 13. Essex-Lopresti P. Fractures of the radial head with distal radioulnar dislocation; report of two

cases. J Bone Joint Surg Br 1951; 33B(2): 244-7. 14. Smith AM, Urbanosky LR, Castle JA, et al. Radius Pull Test: Predictor of longitudinal forearm insta-

bility. J Bone Joint Surg Am 2002; 84-A(11): 1970-6. 15. Burkhartt SS, Wood MB, Lindscheid RL. Posttraumatic recurrent subluxation of the extensor carpi

ulnaris tendon. J Hand Surg Am1982; 7(1): 1-3. 16. Lester B, Halbrecht J, Levy IM et al. “Press test” for office diagnosis of triangular fibrocartilage

complex tears of the wrist. Ann Plast Surg 1995; 35(1): 41-5. 17. Sharma H, Khare GN, Singh S et al. Outcomes and complications of fractures of distal radius (AO

type B and C): volar plating versus nonoperative treatment. J Orthop Sci. 2014 Jul; 19(4): 537-44 18. Arora R, LUtz M, Demi C et al. A prospective randomized trial comparing nonoperative treatment

with volar locking plate fixation for displaced unstable distal radial fractures in sixty-five years of age and older. J Bone Joint Surg Am. 2011 Dec 7; 93(23)2146-53

19. Lindau T, Adlercreutz C, Aspenberg P. Peripheral Tears of the triangular fibrocartilage complex cause distal radioulnar joint instability after distal radial fractures. J Hand Surg Am. 2000; 25; 464-468

20. Mino DE, Palmer AK, Levinsohn EM. The role of radiography and computerized tomography in the diagnosis of subluxation and dislocation of the distal radioulnar joint. J Hand Surg Am. 1983; 8: 23-31.

21. Nakamura R, Horii E, Imaeda T et al. Distal radioulnar joint subluxation and dislocation diagnosed by standard roentgenography. Skeletal Radiol. 1995; 24: 91-94.

22. Pirela-Cruz MA, Goll SR, Klug M et al. Stress computed tomography analysis of the distal radioul-nar joint: a diagnostic tool for determining translational motion. J Hand Surg Am. 1991; 16: 75-82.

23. Nakamura R, Horii E, Imaeda T et al. Criteria for diagnosing distal radioulnar joint subluxation by computed tomography. Skeletal Radiol. 1996; 25: 649-653.

24. Rozental TD, Bozentka DJ, Katz MA, et al. Evaluation of the sigmoid notch with computed tomog-raphy following intra-articular distal radius fracture. J Hand Surg [Am] 2001; 26A: 244-51

159


11

25. Katz MA, Beredjiklian PK, Bozentka DJ et al. Computed tomography scanning of intra-articular distal radius fractures: does it influence treatment? J Hand Surg Am. 2001; 26(3): 415-21

26. Anderson ML, Skinner JA, Felmlee JP et al. Diagnostic comparison of 1.5 Tesla and 3.0 Tesla preop-erative MRI of the wrist in patients with ulnar-sided wrist pain. J Hand Surg Am. 2008 Sep; 33(7): 1153-9.

27. Magee T. Comparison of 3-T MRI and arthroscopy of intrinsic wrist ligament and TFCC tears. AJR Am J Roentgenol. 2009 Jan; 192(1): 80-5.

28. Staron RB, Feldman F, Haramati N et al. Abnormal geometry of the distal radioulnar joint: MR findings. Skeletal Radiol 1994; 23(5): 369-72.

29. Lo IK, MacDermid JC, Bennett JD et al. The radioulnar ratio: a new method of quantifying distal radioulnar joint subluxation. J Hand Surg Am 2001; 26(2): 236-43.

30. Park MJ, Kim JP. Reliability and normal values of various computed tomography methods for quantifying distal radioulnar joint translation. J Bone Joint Surg Am. 2008; 90: 145-153.

31. Hollevoet N, Van Maele G, Van Seymortier P et al. Comparison of palmar tilt, radial inclination and ulnar variance in left and right wrists. J Hand Surg [Br] 2000; 25 (5) 431-433

32. Nederlandse Vereniging voor Heelkunde.Richtlijn distale radius fracturen: diagnostiek en behan-deling. 2010.

33. Nederlandse Vereniging voor Heelkunde. Normering Chirurgische Behandeling 3.0. Juni 2012. 34. Kay S, McMahon M, Stiller K. An advice and exercise program has some benefits over natural

recovery after distal radius fracture: a randomised trial. The Australin Journal of Physiotherapy. 2008: 54; 253-9

35. Stoffelen D, De Smet L, Broos P. The importance of the distal radioulnar joint in distal radial frac-tures. J Hand Surg Br 1998; 23 (4) 507-511

36. Dickson LM, Tham SK. Osteotomy for sigmoid notch obliquity and ulnar positive variance. J Wrist Surg. 2014 Feb; 3(1): 50-4.

37. Jones CW, Lawson RD. One size does not fit all: distal radioulnar joint dysfunction after volar locking plate fixation. J Wrist Surg. 2014 Feb; 3(1): 42-5

38. Omori S, Moritomo H, Murase T et al. Changes in length of the radioulnar ligament and distal oblique bundle after Colles’ fracture. J Plast Surg Hand Surg. 2013; 47: 409-14

39. Moritomo H. The distal oblique bundle of the distal interosseous membrane of the forearm. J Wrist Surg 2013; 2 (1) 93-94

40. Moritomo H, Omori S. Influence of ulnar translation of the radial shaft in distal radius fracture on distal radioulnar joint instability. J Wrist Surg. 2014 Feb; 3(1): 18-21.

12345678910111213

Chapter 12Summary in English

M.M.E. Wijffels

163

Summary in English

12

All studies enclosed in this thesis focus on the influence of posttraumatic distal radioul-nar joint changes on the outcome of distal radius fractures; the radiological aspects in Part II, the acute aspects in Part III and delayed aspects in Part IV. Part I presents a general overview about the clinical and non-clinical aspects of DRUJ instability. Part V presents the general discussion of this thesis, the summaries of this dissertation in English and Dutch, list of publications, acknowledgements and the curriculum vitae of the author.

PART I: CLINICAL AND NON-CLINICAL ASPECTS OF DRUJ INSTABILITY

Due to the osseous anatomy of the articulating distal radius and ulna, the DRUJ yields stabilization by intra- and extracapsular structures. Changes in stabilizing osseous or soft tissue structures may result in an unstable DRUJ. Incidence of DRUJ instability in distal radius fracture patients is reported up to 30%. Despite the negative influence on outcome of distal radius fractures, DRUJ instability remains a diagnostic dilemma. Symptomatic DRUJ instability needs treatment, starting with restoration of the osse-ous anatomy. If not successful non-anatomical repair of stabilizing structures, salvage procedures or DRUJ replacement can be treatment options.

PART II: RADIOLOGICAL ASPECTS

A coronal fracture of the lunate facet may influence the DRUJ. Computed tomogra-phy (CT) scans of the wrist are more sensitive to diagnose these fractures compared to radiographs solely. To date, interobserver agreement for the presence of a coronal fracture of the lunate facet, and its stability, is unknown. In Chapter 2 the null hypoth-esis was tested that agreement between observers for the presence of a coronal split fracture of the lunate facet, and its stability, remains the same when determined with conventional radiographs, compared to radiographs with an additional CT-scan of the wrist. This study was conducted using a web-based, worldwide collaboration of various voluntary observers. Included were radiographs and CT-scans of 16 distal radius frac-tures. Thirty-one observers analyzed conventional radiographs only and 29 observers analyzed the CT-scan additional to the conventional radiographs. The observers were asked to determine presence of a coronal split fracture of the lunate facet and if present, its stability. Interobserver agreement for the presence of a lunate facet fracture was fair both with use of radiographs alone and with use of radiographs and additional CT-scan (kappa = 0.29 and kappa = 0.24, respectively). Interobserver agreement on instability of the coronal split fracture was fair for both radiographs and radiographs with CT-scan (kappa = 0.29 and kappa = 0.32, respectively). With respect to the presence of a coronal

Chapter 12

164

fracture line in the lunate facet, the only significant finding, with respect to observer demographics, was that shoulder and elbow specialists had better agreement with CT-scan than radiographs. With respect to instability of the lunate facet fracture, the only significant findings were that hand and wrist surgeons had a significant greater agreement than other specialists did, and experienced surgeons had greater agreement than less experienced surgeons did. From these data can be concluded that additional CT-scan of the wrist does not improve interobserver agreement in diagnosing coronal split lunate facet fractures, but agreement is dependent on surgical specialism and experience.

To diagnose DRUJ instability several methods using CT-scan of the wrist have been published. Reliability of these methods has only been tested in operatively treated distal radius patients. In Chapter 4 inter- and intraobserver agreement is determined for four methods describing DRUJ translation by use of a CT-scan. Furthermore normal values for the four methods are defined. Two independent observers analyzed the wrist CT-scans of 46 patients treated conservatively for a unilateral distal radius fracture. One observer analyzed the CT-scans two times. Based on the outcome of these measurements inter- and intraobserver agreement was determined. Normal range of motion was based on measurements of the uninjured wrist of the included patients. Best inter- and intrao-bserver agreement was found using the Epicenter Method (intraclass correlation coef-ficient (ICC) = 0,73 and 0.82 respectively). Normal values varied widely, dependent on the positioning of the wrist. Based on this study can be concluded that the Epicenter Method is most reliable for determination of DRUJ translation using CT-scan, but normal values vary widely which compromises the use of CT-scan for diagnosing DRUJ instability.

PART III: ACUTE TREATmENT

A distal radius fracture accompanied by an ulnar styloid fracture (USF) may increases the risk of DRUJ instability. This assumption is based on heterogeneous data including several distal radius treatment modalities. The influence of an USF on conservatively treated distal radius fractures remains unclear. Due to a disrupted triangular fibrocarti-lage complex, an USF may result in increased distal radius fracture instability compared to an intact USF. This would result in more secondary dislocation after closed reduction of a distal radius fracture. In Chapter 5 the influence of an USF on secondary dislocation of a distal radius fracture is analyzed. One-hundred, conservatively treated, distal radius fractures were included after closed reduction. Fifty-eight fractures had an accompany-ing USF and were compared to the 42 single distal radius fractures, focusing on volar tilt, radial inclination and ulnar variance. In contrast to the pre-reduction situation, no differences in the radiological parameters were found between groups directly after the

165

Summary in English

12

closed reduction. After 42 days of follow-up in the USF group, a statistically significant reduction in radial inclination was found. This means decreased distal radius fracture stability in presence of an USF.

In Chapter 6 the assumption that non-union of an USF leads to diminished wrist function is tested, after consolidation of the distal radius fracture. Eighteen distal radius patients with a non-union of the USF were compared to 16 patients with consolidation of the USF, focusing on the outcome of the distal radius fracture. Mean follow-up was 30 months after operative treatment. The two groups were equal in baseline characteristics and no differences in range of wrist motion, DRUJ instability or outcome of subjective questionnaires were found at final follow-up. No plausible explanation could be found for the statistical significant difference in grip strength between groups. From these data can be concluded that a USF non-union has no influence on the outcome of a distal ra-dius fracture. Chapter 7 presents the results of a meta-analysis focusing on the influence of a USF non-union on the outcome of a distal radius fracture. After a literature review, 6 studies were analyzed, including 365 distal radius fracture patients of which 135 had an USF non-union and 230 an USF union. Raw data were available for 105 of these patients. Comparing the USF union and non-union groups revealed no differences in outcome of quality of life questionnaires, functional results, grip-strength, pain or DRUJ instability. From these data can be concluded that an USF non-union should not be a separate target for surgery. The influence of DRUJ instability on the outcome of a conservatively treated distal radius fracture after long-term follow-up is analyzed in Chapter 8. Seventeen pa-tients tested clinically positive for DRUJ instability. These patients were compared to 32 clinical DRUJ stable patients at a mean follow-up of 4.2 years. No statistically significant differences, with exception of wrist flexion, were found between groups, with regard to wrist function, strength, pain or outcome of quality of life questionnaires. Therefor the role of DRUJ instability on the outcome of conservatively treated distal radius fractures seems limited.

PART Iv: DELAYED TREATmENT

Posttraumatic DRUJ changes may result in pain or loss of wrist function. A treatment-algorithm for DRUJ instability starts with restoration of the osseous anatomy of both radius and ulna. Correction of a distal radius malunion may be complicated by callus formation. A technique to correct for nascent malunions of the distal radius is the “ex-tended flexor carpi radialis approach” followed by volar plating. Although promising, this technique has never been evaluated formally. In Chapter 9, 35 patients treated with this technique are evaluated, after a mean of 20 months of follow-up, focusing on wrist function, complications and radiological outcome. The mean range of flexion-extension

Chapter 12

166

of the injured wrist was 132˚, with a mean pronosupination of 169˚. With the exception of the intra-articular step, all radiological parameters showed statistically improvement comparing pre- with postoperative situation. No complications were found except for loss of reduction of 5˚dorsal angulation in one patient, without clinical consequences. Based on these results can be concluded that the “extended flexor carpi radialis approach” followed by volar plating is safe and effective for correction of nascent malunions of distal radius fractures.

If anatomic or non-anatomic reconstruction techniques are not successful, a salvage procedure may be indicated. Several treatment options have been described to treat restricting or symptomatic DRUJ abnormalities. Darrach described, among others, an operative technique to relieve pain and improve function by resecting the distal ulna. In Chapter 10 the results are presented of a study focusing on the results of a Darrach procedure with the aim of improving wrist function in, among others, patients with posttraumatic DRUJ changes. After a mean of 21 months, 26 patients were evaluated for postoperative wrist pain and –function. Compared to the pre-operative situation, a statistical significant improvement in both parameters was found. Based on these results can be concluded that the Darrach procedure is successful for pain relief and improve-ment of wrist function in patients with disruption of the normal DRUJ biomechanics.

PART v: GENERAL DISCUSSION AND FUTURE PERSPECTIvES

In the general discussion (Chapter 11) must be stated that DRUJ instability is still a diag-nostic dilemma. The lack of reliable clinical tests and varying individual normal values in radiological findings, increase the risk of malpractice. Future research has to focus on comparison of the DRUJ movement in the injured and uninjured wrist individually, either clinically of radiologically. To improve the outcome of distal radius treatment and its complications, dedicated teams with various specialized specialist for pre-, per- and postoperative care should be formed, which treat a set amount of patients per time frame. The role of ulnar styloid fractures on distal radius fractures has been evaluated thoroughly and is limited, even if resulting in a non-union and should therefore not be seen as a surgical target. Several save and effective operative procedures are available to correct DRUJ instability.

12345678910111213

Chapter 13Appendices

Summary in Dutch (Nederlandse samenvatting), List of publications, Acknowledgements

(Dankwoord), Curriculum Vitae

171

Summary in Dutch (Nederlandse samenvatting)

13

SUmmARY IN DUTCH (NEDERLANDSE SAmENvATTING)

De studies die deel uitmaken van dit proefschrift zijn gericht op de invloed van post-traumatische veranderingen in het distale radioulnaire (DRU) gewricht op de uitkomst van distale radius fracturen; de radiologische aspecten in Deel 2, de acute aspecten in Deel 3 en de late gevolgen en behandeling in Deel 4. Een overzicht van de stand van zaken over instabiliteit van het DRU-gewricht is gepresenteerd in Deel 1. Deel 5 bevat de algemene discussie van dit proefschrift, de samenvatting in Engels en Nederlands, lijst met publicaties en het curriculum vitae van de auteur.

Deel I: Klinische en niet klinische aspecten van distale radioulnaire gewrichtsinstabiliteit

Het DRU gewricht heeft geen intrinsieke stabiliteit en wordt daarom omgeven door extra- en intracapsulaire stabilisatoren. Verandering van zowel de weke delen als de os-sale anatomie kan voor verstoring zorgen van deze stabiele situatie, resulterend in DRU-gewrichtsinstabiliteit. Zo wordt in tot wel 30% van de patiënten met een distale radius fractuur DRU-gewrichtsinstabiliteit gevonden. Ondanks dat dit voor een minder goede uitkomst van de distale radius op lange termijn lijkt te zorgen, is de beste manier om DRU-gewrichtsinstabiliteit diagnosticeren onduidelijk. Behandeling lijkt in symptomati-sche patiënten aangewezen en kan bestaan uit herstel van de stabiliserende anatomie. Wanneer dit niet succesvol is, kan uitgeweken worden naar niet anatomische, stabilise-rende ingrepen, zogenaamde “salvage procedures”, of zelfs DRU-gewrichtsvervanging.

Deel II: Radiologische aspecten

Een van de fracturen die het DRU-gewricht beïnvloedt, is een coronale fractuur van de fossa van het os lunatum. Gebleken is dat deze fracturen op een computed tomography (CT) scan beter te diagnosticeren zijn dan op conventionele röntgenfoto. De overeen-stemming tussen beoordelaars van zo’n CT en/of röntgenfoto’s, over de aanwezigheid en instabiliteit van een dergelijke fractuur, is nog niet bekend. In hoofdstuk 2 wordt de nulhypothese getest dat de overeenstemming tussen beoordelaars, over de aanwezig-heid van een (instabiele) coronale fractuur van de fossa van het os lunatum, hetzelfde is wanneer een röntgenfoto met of zonder CT-scan beoordeeld wordt. Dit wordt gedaan door middel van een nieuw, web-based, wereldwijd samenwerkingsverband waarbij multipele beoordelaars mee kunnen doen aan soortgelijk onderzoek. Van 16 intra-articulaire distale radius fracturen was zowel een röntgenfoto als een CT-scan gemaakt. Eenendertig beoordelaars bekeken alleen de röntgenfoto’s en 29 beoordelaars röntgen-foto’s met een aanvullende CT-scan, met de vraag of er een coronale fractuur van de fossa van het os lunatum aanwezig was en, indien aanwezig, of deze als stabiel beschouwd moest worden. De overeenstemming tussen beoordelaars van röntgenfoto’s blijkt matig

Chapter 13

172

te zijn voor de aanwezigheid van een fractuur (kappa = 0,29) en neemt niet toe bij het gebruik van een additionele CT-scan (kappa = 0,24). Hetzelfde werd gevonden voor de instabiliteit van de fractuur. Wel werd een significante verbetering(p=0.04) gevonden in de overeenstemming over de aanwezigheid van een coronale fractuur, ten faveure van specialisten in schouder- en elleboogschirurgie vergeleken met andere specialisten. Wat betreft fractuurinstabiliteit, bepaald met röntgenfoto’s met CT-scan, zorgde een speci-alisatie in hand- en polschirurgie en een langere praktijkvoering voor significant meer overeenstemming tussen beoordelaars. Geconcludeerd kan worden dat een CT-scan de overeenstemming tussen beoordelaars, die afhankelijk is van specialisme en ervaring, niet doet toenemen ten opzichte van röntgenfoto’s alleen.

Om DRU-gewrichtsinstabiliteit te diagnosticeren met CT-scan zijn verschillende methoden beschreven. De betrouwbaarheid hiervan is beperkt, maar die is tot nu toe alleen bepaald in patiënten met een operatief behandelde distale radius fractuur. In hoofdstuk 4 wordt de overeenstemming tussen beoordelaars bepaald, van vier metho-den voor het beschrijven van DRU gewrichtstranslatie, met een CT-scan. Tevens worden normaalwaarden gedefinieerd voor DRU gewrichtsbeweging, voor alle 4 de methoden. Twee onafhankelijke beoordelaars analyseren de CT-scans van 46 patiënten, van beide polsen, welke conservatief behandeld zijn voor een distale radiusfractuur. Hiermee wordt de overeenstemming voor het bepalen van DRU gewrichtstranslatie tussen be-oordelaars bepaald. Een van de beoordelaars bekijkt de CT-scan voor een tweede keer waarmee de overeenstemming tussen twee metingen van dezelfde beoordelaar wordt vastgesteld. De normaalwaarden voor de 4 methoden, worden gebaseerd op gemid-delde uitkomsten van de eerste metingen van beide beoordelaars, van de gezonde pol-sen. De beste overstemming tussen de beoordelaars, redelijk, wordt gevonden met de Epicenter Method (intraclass correlation coefficient (ICC) = 0,73). De Epicenter Method blijkt ook de beste overeenstemming in herhaalde beoordelingen op te leveren (ICC= 0,82). De normaalwaarden, welke afhankelijk zijn van de draaiing van de pols, blijken ver uit elkaar te liggen, met een grote spreiding om het gemiddelde. Geconcludeerd kan worden dat de Epicenter Method het meest betrouwbaar is voor het bepalen van DRU-gewrichtsbeweging met een CT-scan, maar dat het stellen van de diagnose DRU-gewrichtsinstabiliteit met CT-scan wordt bemoeilijkt door een grote spreiding in normaalwaarden.

Deel III: Acute behandeling

Een bijkomende fractuur van het processus styloideus ulna (PSU) bij een distale radius fractuur, geeft een grotere kans op DRU-gewrichtsinstabiliteit. Deze stelling is geba-seerd op heterogene data, waarbij patiënten met een de distale radius fractuur zowel conservatief als operatief behandeld werden. De invloed van een PSU op conservatief behandelde distale radius fracturen blijft daarom onduidelijk. Hypothetisch kan er in

173


13

het geval van een PSU fractuur meer instabiliteit van het distale radius fragment be-staan, waardoor een verhoogde kans op secundaire dislocatie. In hoofdstuk 5 wordt de invloed van een PSU fractuur op de secundaire dislocatie van een gereponeerde distale radius fractuur geanalyseerd. Honderd, gereponeerde, conservatief behandelde, distale radiusfracturen, waarvan 58 met een bijkomende PSU fractuur, werden radiologisch ver-volgd gedurende gemiddeld 42 dagen. Na repositie bestond, in tegenstelling tot voor de repositie, geen verschil in dorsale angulatie, radiale inclinatie of ulnaire variantie van de distale radius. Echter, na 42 dagen werd er in de groep met een PSU fractuur significant minder inclinatie gemeten. Dit betekent dat een fractuur van het PSU gepaard gaat met verminderde fractuurstabiliteit. De klinische consequentie hiervan is, dat een patiënt met een distale radiusfractuur met een PSU fractuur vaker radiologisch gecontroleerd zal moeten worden, dan wanneer de PSU fractuur niet aanwezig is. In hoofdstuk 6 wordt de vraag beantwoord of een pseudartrose van de basis van een PSU fractuur lijdt tot meer pijn, verminderde polsfunctie, DRU gewrichtsinstabiliteit en/of slechtere score op subjectieve vragenlijsten, bij consolidatie van de distale radius fractuur, in vergelijking met patiënten waarbij de PSU fractuur wel geconsolideerd is. Achttien patiënten met een PSU-basis pseudartrose worden vergeleken met 16 patiënten waarbij de PSU fractuur wel consolideerde, gemiddeld 30 maanden na de operatieve behandeling van de distale radius fractuur. De twee te vergelijken groepen waren gelijk wat betreft basis karakteris-tieken. Er werden geen significante verschillen gevonden tussen de groepen wat betreft bewegingsuitslagen, uitkomsten van subjectieve vragenlijsten en DRU gewrichtsinsta-biliteit. Het gevonden statistisch significante verschil in grijpkracht, ten nadele van de groep met geconsolideerde PSU fractuur, kon niet worden verklaard. Op basis van deze studie werd geconcludeerd dat aanwezigheid van een pseudartrose van een PSU frac-tuur niet tot slechtere uitkomsten na een distale radius fractuur lijdt. Hoofdstuk 7 toont een meta-analyse die de vraag beantwoord of er invloed is van een pseudoartrose van een PSU fractuur op de uitkomst van een distale radiusfractuur. Na een systematische zoektocht konden 6 studies geïncludeerd worden, waarbij 135 distale radiusfractuur patiënten met een PSU pseudoartrose werden vergeleken met 230 patiënten met een geconsolideerde PSU fractuur. Van 105 patiënten waren ruwe data beschikbaar voor deze analyse. In deze studie werden geen verschillen gevonden tussen de twee groepen, wat betreft subjectieve vragenlijsten, functionele uitkomst, grijpkracht, pijn of DRU gewrichtsinstabiliteit. Daarom lijkt er, op basis van deze gegevens, geen indicatie voor operatieve behandeling van een PSU pseudoartrose te bestaan. In Hoofdstuk 8 wordt een studie gepresenteerd, waarin de invloed van klinische DRUJ instabiliteit op de uitkomst van een conservatief behandelde distale radiusfractuur, op lange termijn, wordt geanalyseerd. Hiertoe worden 17 patiënten met de klinische verdenking op DRU-gewrichtsinstabiliteit vergeleken met 32 klinisch DRU-gewricht stabiele patiënten. Ruim vier jaar na de distale radiusfractuur is er tussen de groepen, welke vergelijkbaar zijn wat

Chapter 13

174

basiskarakteristieken betreft, geen significant verschil gevonden in polsfunctie, kracht, pijn of uitkomst van subjectieve vragenlijsten.

Deel Iv: Lange termijn behandeling

Posttraumatische DRU-gewrichtsveranderingen kunnen voor klachten zorgen zoals pijn en/of functieverlies. Het behandel-algoritme voor DRU-gewrichtsinstabiliteit begint bij het herstellen van de ossale anatomie van zowel distale radius als distale ulna. Stands-correctie van een distale radiusfractuur wordt bemoeilijkt door callusvorming. Een chirurgische techniek die beschreven is om een standscorrectie uit te voeren van deels geconsolideerde distale radius fracturen is de “extended flexor carpi radialis benadering”, gevolgd door een volaire plaat osteosynthese. Hoewel veelbelovend, is deze techniek is nooit geëvalueerd op het gebied van veiligheid en bruikbaarheid. In Hoofdstuk 9 worden 35 patiënten beschreven, welke 20 maanden na de standscorrectie van de distale radi-usfractuur met genoemde techniek, werden onderzocht op polsfunctie, postoperatieve complicaties en radiologische stand van de distale radius. Het gemiddelde flexie- en extensiebereik van de aangedane pols was 132˚, met een gemiddeld pronosupinatie bereik van 169˚. Met uitzondering van het intra-articulaire hoogteverschil was er een significante verbetering van alle postoperatieve radiologische parameters, vergeleken met de pre-operatieve situatie. In één patiënt trad een verlies van 5˚ palmaire angulatie op, zonder klinische consequenties. Verder deden zich geen complicaties voor. Hieruit kan geconcludeerd worden dat de “extended flexor carpi radialis benadering” gevolgd door volaire plaat osteosynthese, veilig bruikbaar is voor het corrigeren van gedeeltelijk genezen distale radius fracturen met een afwijkende stand.

Als anatomische of niet-anatomische reconstructie technieken niet succesvol zijn, kan een “salvage procedure” geïndiceerd zijn. Verschillende technieken zijn hiervoor beschreven, waaronder de Darrach procedure. Hierbij wordt een distale ulna resectie uitgevoerd met wisselende resultaten. In hoofdstuk 10 wordt een studie gepresenteerd waarin het succes van de Darrach procedure wordt geëvalueerd, met het oog op het herwinnen van functie, in patiënten met, onder andere, posttraumatische DRUJ veran-deringen. Zes-en-twintig patiënten werden gemiddeld 21 maanden na de Darrach pro-cedure onderzocht op pijn, polsfunctie en postoperatieve complicaties. De gemiddelde polsfunctie was significant toegenomen en het aantal patiënten met pijn was significant afgenomen, wanneer de preoperatieve met de postoperatieve situatie werd vergeleken. Op basis hiervan mag geconcludeerd worden dat de Darrach procedure succesvol is in het verbeteren van de polsfunctie en verminderen van de pijnklachten in patiënten met een verstoorde DRUJ functie.

175


13

Deel v: Algemene discussie en toekomst visie

Concluderend in de algemene discussie (Hoofdstuk 11) moet worden gezegd dat het stellen van de diagnose DRUJ instabiliteit een probleem is. Het ontbreekt vooral aan betrouwbare klinische testen en individueel bruikbare normaalwaarden, waarbij het gevaar voor over- of onderbehandeling dreigt. In de toekomst zal vooral onderzoek gedaan moeten worden naar het vergelijken van de aangedane pols met de niet aange-dane pols in de individuele patiënt met DRU-gewrichtsinstabiliteit na een distale radius fractuur, zowel klinisch als radiologisch. Om de uitkomsten van behandeling van distale radius fracturen te verbeteren zullen specialistische teams, pre-, per- en postoperatieve zorg moeten leveren en een minimaal aantal behandelingen per tijdvak moeten uitvoe-ren. De rol van een processus styloideus ulna fractuur is grondig bestudeerd, en gezien de beperkte rol op de uitkomst van een distale radiusfractuur, behoeft deze, zelfs in het geval van een non-union, geen chirurgische behandeling. Er bestaan veilige en suc-cesvolle operatieve methoden om DRU_gewrichtsinstabiliteit te corrigeren.

Chapter 13

176

PUBLICATIONS

1. M.M.E. Wijffels, S.B. de Haseth, P. Ott, S.A. Meylaerts, G.R. Roukema, S. Rhemrev. Is fractuurstabilisatie met het Less Invasive Stabilization System een adequate en veilige methode; ervaring met 52 fracturen van het distale femur en proximale tibia. Nederlands Tijdschrift voor Traumatologie. 2008:6;165-71

2. P.B. de Witte, M.M.E. Wijffels, D. Ring, J.B. Jupiter. The Darrach-procedure for post-traumatic reconstruction. Acta Orthop Belg. 2009 Jun;75(3):316-22.

3. M.M.E.Wijffels, J.B. Jupiter. Distal Radial Shortening Osteotomy and Volar Plating for treatment of Kienböck’s Disease. Current Orthopaedic Practice. 2009 Sept/Oct;20(5):561-5.

4. M.M.E. Wijffels, D. Ring. The Influence of Non-union of the Ulnar Styloid on Pain, Wrist Function and Instability after Distal Radius Fracture. Journal of Hand and Microsur-gery. 2011 Jun;3(1):11-4.

5. Kunz LI, Lapperre TS, Snoeck-Stroband JB, Budulac SE, Timens W, van Wijngaarden S, Schrumpf JA, Rabe KF, Postma DS, Sterk PJ, Hiemstra PS; Groningen Leiden Uni-versities Corticosteroids in Obstructive Lung Disease Study Group. Smoking status and anti-inflammatory macrophages in bronchoalveolar lavage and induced sputum in COPD. Respir Res. 2011 Mar 22;12:34.

6. Budulac SE, Postma DS, Hiemstra PS, Kunz LI, Siedlinski M, Smit HA, Vonk JM, Rutgers B, Timens W, Boezen HM; Groningen Leiden Universities Corticosteroids in Obstructive Lung Disease (GLUCOLD) study group. Multidrug resistance-associated protein-1 (MRP1) genetic variants, MRP1 protein levels and severity of COPD. Respir Res. 2010 May 20;11:60.

7. Lapperre TS, Snoeck-Stroband JB, Gosman MM, Jansen DF, van Schadewijk A, Thiadens HA, Vonk JM, Boezen HM, Ten Hacken NH, Sont JK, Rabe KF, Kerstjens HA, Hiemstra PS, Timens W, Postma DS, Sterk PJ; Groningen Leiden Universities Corticoste-roids in Obstructive Lung Disease Study Group. Effect of fluticasone with and without salmeterol on pulmonary outcomes in chronic obstructive pulmonary disease: a randomized trial. Ann Intern Med. 2009 Oct 20;151(8):517-27.

8. Kunz LI, Strebus J, Budulac SE, Lapperre TS, Sterk PJ, Postma DS, Mauad T, Timens W, Hiemsta PS; Groningen Leiden Universities Corticosteroids in Obstructive Lung Disease Study Group. Inhaled steroids modulate extracellular matrix compositio in bronchial biopsies of COPD patients: a randomized, controlled trial. PLoS One 2013 May 7;8(5):e63430

9. Geert A. Buijze, Mathieu M.E. Wijffels, Thierry Guitton, Ruby Grewal, C. Niek van Dijk, David Ring and The Science of Variation Group Inter-Observer Reliability for the Diagnosis of Scaphoid Waist Fracture Union using Computed Tomography. J Hand Surg Am. 2012 Feb;37(2):250–4

177

Publications

13

10. Mathieu M.E. Wijffels, MD, Jorge L. Orbay, MD, Igor Indriago, MD, David Ring, MD, PhD. The Extended Flexor Carpi Radialis Approach for Partially Healed Mal-aligned Fractures of the Distal Radius. Injury, Int. J. Care Injured 43 (2012) 1204–1208.

11. Mathieu M.E. Wijffels, Thierry Guitton, D. Ring. Interobserver Variation in the Diagnosis of Coronal Articular Fracture Lines in the Distal Radius. HAND (2012) 7:271–275

12. M.M.E. Wijffels, P.R.G. Brink, I.B. Schipper. Distal radioulnar joint instability, the current status. The Open Orthopaedics Journal, 2012, 6, 204-210

13. M. Valburg, M.M.E. Wijffels, I.B. Schipper. Ulnar styloid fractures affect dislocation of non-operatively treated distal radius fractures. European Journal of Trauma and Emergency Surgery. 2013 April 39(2);151-157

14. M.M.E. Wijffels, A. Patel, K.A. Bartlema, Z. Rahimtoola. A simple and low-cost external fixator for infected hand injuries. Journal of Hand and Microsurgery 2012(2).

15. M.M.E. Wijffels, J. Keizer, G.A. Buijze, Y. Zenke, P. Krijnen, N.W.L. Schep, I.B. Schipper. Ul-nar styloid process non-union and outcome in patients with a distal radius fracture: A meta-analysis of comparative clinical trials. Injury. 2014;12:1889-95

Chapter 13

178

PRESENTATIONS

1. May 2015: The value of CT in detecting distal radio ulnar joint instability after distal radius fractures. ECTES, Amsterdam

2. May 2014: Determination of reliability for CT-scan related scoring techniques in diagnosing DRUJ instability after conservatively treated distal radius fractures. ECTES, Frankfurt, Germany

3. Nov 2013: De invloed van PSU-fractuur op de uitkomst op lange termijn van een conservatief behandelde distale radiusfractuur. Traumadagen, Amsterdam, the Netherlands.

4. Nov 2013: Risk factors for distal radio ulnar joint instability. Najaarsvergadering Ned. Ver. Voor Handchirurgie. Arnhem, the Netherlands

5. Nov 2013: The influence of an ulnar styloid process fracture on the outcome of a distal radius fracture. Najaarsvergadering Ned. Ver. Voor Handchirurgie. Arnhem, the Netherlands

6. May 2012: Impact of ulnar styloid fractures in non-operatively treated distal radius fractures. ECTES, Basel, Switzerland.

7. May 2012: The Extended Flexor Carpi Radialis Approach for Partially Healed Mal-aligned Fractures of the Distal Radius. ECTES, Basel, Switzerland. (Winner ESTES Congress Grant 2012) (oral poster presentation)

8. Feb 2012: The value of CT-scans in the diagnosis of scaphoid non-union. Research Meeting BG-Unfallklinik, Department of hand, plastic, reconstructive and burnsur-gey, Tübingen, Germany

9. Jun 2011: Distal radio-ulnar instabilityt. An overview for daily practice. Advanced Trauma Meeting, Dutch Trauma Society, Noordwijk, the Netherlands.

10. May 2011: The effect of an ulnar styloid proces fracture on the outcome of a distal radius fracture after conservative treatment. Annual meeting Dutch Surgical Soci-ety.

11. Sep 2008: Radial shortening osteotomy for Lichtman stage II and IIIA Kienbocks; good but not great. 63th Annual Meeting of the American Society for Surgery of the Hand. Chicago, Il, USA.

12. May 2008: Base of Ulnar Styloid Fracture with Distal Radius Fracture: Does Non-union Affect Outcome? 9th European congress of trauma and emergency surgery. Budapest, Hungary.

13. May 2008: Outcome of the Less Invasive Stabilization System in the treatment of complex peri-articular knee-fractures in the elderly. 13th European society of sports traumatology, knee surgery and arthroscopy. Porto, Portugal.

179

Presentations

13

14. Feb 2008: Radial shortening osteotomy for Lichtman Stage II and IIIA Kienbocks: good but not great. 16th Bone vascularization and fracture healing in the upper extremity Brussel, Belgium.

15. Dec 2007: A Prospective Randomized Controlled Trial of Dynamic vs. Static Pro-gressive Elbow Splinting for Post-Traumatic Elbow Stiffness. New England Hand Surgery Society. Sturbridge, MA, USA.

16. Dec 2007: Radial shortening osteotomy for Lichtman stage II and IIIA Kienbocks; good but not great. New England Hand Surgery Society. Sturbridge, MA, USA.

17. Nov 2007: Injection of dexamethasone vs. placebo for lateral arm pain. New Eng-land Orthopaedic Society, Boston, Massachusetts, USA.

18. Nov 2007: The Darrach-procedure for post-traumatic reconstruction. New England Orthopaedic Society, Boston, Massachusetts, USA.

19. Nov 2007: Overview occult scaphoid fracture research in Medical Center Haa-glanden. Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.

20. Oct 2007: Less Invasive Stabilization System, a reliable internal external fixator in proximal tibia fractures? Results of 26 cases. World congress on external fixation. Cario, Egypt.

21. May 2007: Less invasive stabilization system (LISS) in the treatment of distal femo-ral and proximal tibial fractures; radiologic and clinical outcome in 50 patients. 1st Joint Congres EATES/ETS, Graz, Austria.

22. May 2007: Suspected scaphoid fractures: bone scintigraphy versus clinical out-come. 1st Joint Congres EATES/ETS, Graz, Austria.

23. May 2007: Observer variation of MR imaging for suspected scaphoid fractures. 1st Joint Congres EATES/ETS, Graz, Austria

24. Sep 2004: “Longterm follow up of corrected Total Anomalous Pulmonary Venous Drainage” Fall meeting Dutch Thoracic Surgery Society. Driebergen, the Nether-lands.

181

Acknowledgements

13

ACKNOWLEDGEmENTS

The risk of acknowledgements lies in forgetting important people. To avoid this risk, I would like to thank everybody who has contributed to fulfill this thesis. It has been a long journey, but we succeeded. Thanks for all your enthusiasm and encouragement. I really appreciate it.

However, some people deserve more attention than only a few sentences.

Dear prof. Schipper, it took a while to get used to the approval to call you Inger. From our first meeting till the last draft of my thesis, I got inspired by your working ethos. Your answers on all my questions, within a few hours or days, worked stimulating for me. This secured the progress in this project. Without your ability to keep our research project limited and perspicuous, not all of this would have been possible.

Dear Pieta Krijnen, it was always a pleasure to discuss on research ideas, statistical meth-ods and significant findings. Your ability to revise manuscripts is unsurpassed and has contributed enormously to this thesis.

Dear dr. Ring, it has been a while since I visited your department in Boston. Although 7 year ago, I am still impressed by your ability to supervise many projects and I am proud to be a member of your imperium, which is still growing and improving. I really appreci-ate your effort in this project.

Dear co-authors, it was a pleasure to work with you. I learned a lot from this collabora-tion, in different ways, which brought me to this dissertation.

Dear Wouter and Pieter, dear paranimphs, dear best friends. After arranging a fabulous wedding for us, I trusted you guys to be in the lead here as well. We enjoyed many pleas-ant hours, with both serious and small talk. We are still discussing the best doctors for bony lesions; orthopedic or trauma surgeons. To come a little bit closer to a conclusion I did some research at an orthopedic office. Now it is your turn…

Dear Olav, Monique, Kristin and Alex. When you’re dating a girl, you realize that there will be a day, that you have to meet her family. In my situation, meeting the family-in-law was a real pleasure. The last 11 years have been really great and I really appreciate and enjoyed it, especially our nice long conversations, either via skype or face to face.

Chapter 13

182

Dear Thomas, as an older brother you showed me many times and in several fields, where to go in life. I really respect the way you and Anne are running your family, next to your demanding job, social activities and sports.

Dear Katrien, I am blessed to have a sister like you. Your thoughtfulness is great. With a lot of humor and fun, you can create coziness wherever you go. It is always great fun to be with you, Michiel and the boys!

Lieve pap en mam, het is moeilijk waar te beginnen als ik jullie wil bedanken. Onze zorgeloze jeugd heeft ook mij gebracht waar ik nu ben. Een van de belangrijkste dingen die ik van jullie heb geleerd is werken en het werk af te maken. Als ik die eigenschap niet van huis uit had meegekregen, had ik dit boekje nooit af gekregen. Ik vind het heerlijk om bij jullie thuis te zijn, in die warme omgeving. Dank daarvoor!

Dear Stéphanie, you have changed my life in such a positive way. You have the power to stimulate, correct, calm down and inspire me, all in one, exactly at the right time. I feel very lucky being on your side. Without your patience and understanding, this thesis would have never ended. The birth of our sweet Emma has brought us even more luck then we already had. I am proud of you as a mum, as my wife and as my best friend!

183

Curriculum vitae

13

CURRICULUm vITAE

Mathieu M.E. Wijffels was born on May 10th 1980 in Waterlandkerkje. He attended the Zwincollege in Oostburg for 6 years, and graduated from High School in 1998. He started his study Biomedical Sciences at the University of Leiden that same year. After one year he changed this study for Medicine. After completion of his medical study in 2006, he worked as a surgical resident in Medisch Centrum Haaglanden (dr. A. de Mol van Otterloo) in the Hague for 2 years. During this period in 2007 he visited Harvard Medical School, Boston, MA, USA (dr. D. Ring) for a research fellowship during 6 months. In 2008 he started his training as a general surgeon, primarily in Bronovo Hospital (dr. H.J. Smeets) and Leiden University Medical Center (prof. dr. J.F. Hamming). It was during his research fellowship that he became enthusiastic in performing studies in the field of wrist trauma. After finishing his surgical training, he started a traumasurgical fellowship in Erasmus Medical Centre, Rotterdam (prof. dr. Verhofstad) since July 1st 2014. In July 2015 he joined the traumatological staff in the Erasmus Medical Centre.

the clinical and non-clinical aspects of distal radioulnar joint

Documents