Skeletal Radiol (2005) 34: 500–512DOI 10.1007/s00256-005-0956-1 REVIEW ARTICLE

Stefano BianchiCarlo MartinoliIbrahim Fikry Abdelwahab

Received: 23 December 2004Revised: 11 March 2005Accepted: 1 June 2005Published online: 6 July 2005# ISS 2005

Ultrasound of tendon tears. Part 1:general considerations and upper extremity

Abstract The role of ultrasound (US)in assessing musculoskeletal disor-ders is persistently increasing becauseof its low cost, readiness, noninva-siveness, and possibility of allowing adynamic examination. Secondary toincreased sport practice, tendon tearsare more frequently observed in dailymedical practice. They deserve earlydiagnosis to allow proper treatmentthat can limit functional impairment.The aim of this review article istwofold: to illustrate the US appear-ance of normal tendons and todescribe the US findings of the mostcommon tendon tears.

Keywords Tendons . Tendon tears .Trauma . Ultrasound . Sonography

Introduction

Tendon tears are common conditions in daily medical prac-tice. In most cases, preexisting degenerative changes [1],systemic diseases [2–6], or recurrent microtraumas predis-pose a tendon to rupture. The recent increase in frequencyof tendon tears is mainly related to ageing and a rise insporting activities of the general population. Althoughclinical evaluation remains the mainstay for the early andaccurate diagnosis of a tendon tear, posttraumatic localedema and severe pain can limit physical examination,and even complete tears can be missed. But early diag-nosis can reduce patient discomfort and guide the correctchoice of surgical versus medical treatment.

When a tendon tear is suspected clinically, imaging isrequired to confirm the clinical suspicion, differentiate apartial from a complete tear, and detect the degree of the

proximal tendon end retraction. Different modalities couldbe used in this effort, each presenting advantages anddisadvantages. The final choice of modality depends notonly on the particular characteristics but also on local fac-tors, including availability. However, tendon assessmentrepresents one of the best applications of musculoskeletalultrasound (US) [7–12].

Recent developments in high-frequency broadband trans-ducers have enhanced the diagnostic capacity of US tovisualize normal internal tendon arrangement and periten-dinous structures such as retinacula and synovial bursae.Small portable US scanners equipped with 7.5-MHz lineartransducers are also available for examining patients im-mediately after injury, even on the sports field. However,they have reduced image quality and diagnostic capabili-ties when compared with larger state-of-the-art equipment,and their accuracy in evaluating smaller structures of the

S. Bianchi (*)Fondation des GrangettesChene-Bougeries;Institut de Radiologie,Clinique des GrangettesChene-Bougeries,Geneva, Switzerlande-mail: stefano.bianchi@bluewin.ch

C. MartinoliCattedra “R” Radiologia, DICMI,Università di Genova,Genova, Italy

I. F. AbdelwahabDepartment of Radiology,Coney Island Hospital,New York, NY, USA

wrist and hand is restricted. They do allow detection ofmost tendon and myotendinous junction tears of the lowerextremity, resulting in cessation of the activity and pre-vention of further serious injuries. There is little doubt thatfurther technical and software developments will improveimaging with miniaturized equipment in the near future.

In most patients in whom the examination is performedsome days after the trauma, high-resolution US can avoidthe use of more sophisticated, expensive, or invasive diag-nostic modalities. The dynamic nature of US can enhancethe demonstration of several tendon pathologies, includingperitendinous adhesions and posttraumatic instability. Themain disadvantage of US is operator dependence, relatedmainly to the slow learning curve. The small field of viewand less accurate evaluation of deep tendons are nowadayspartially offset by accurate reporting, extended field of viewmodality, and use of 5-MHz transducers with proper focusedpositioning.

Normal tendon structure and US appearance

Macroscopic anatomy

The macroscopic appearance of tendons is variable andreflects the forces acting on them [13]. For example, thepatellar tendon not only transmits the force generatedby the quadriceps tendon from the patella to the anterior

tibial tuberosity, but it also stabilizes it against the troch-lea and prevents instability in the transverse plane. Thus,it has a large flattened shape, well suited for maintainingcorrect position of the sesamoid during knee flexion.Several tendons split proximal to their bone insertion intoa number of slips that allow an efficient distribution offorces to different bones. The distal insertion of the tibialisposterior tendon at the level of the tarsal bones, for ex-ample, fans out to reach the navicular tubercle as well asthe first cuneiform and the inferior aspect of the 1st and2nd metatarsal. This wide area of insertion allows suc-cessful maintenance of the normal inferior concavity ofthe longitudinal foot arch.

Tendons can be formed by a single, homogeneousbundle of connective tissue or by multiple laminae (com-plex tendons). Different peritendinous structures allowcorrect tendon function. These differ in tendons with astraight course from those with a curvilinear course andare subject to local friction over bones or retinacula. Theouter surface of the former tendons, such as the Achillestendon, is surrounded by the peritenon, which acts as aprotective sheath and enhances mobility [14]. Tendons ofthe second type are surrounded by a synovial sheath,containing in normal conditions a thin film of synovialfluid that reduces tendon abrasions and preserves theirintegrity. Tendon retinacula are fibrous bands that main-tain the tendons in the proper and efficient anatomicposition. Retinacula are found at anatomic locations where

Fig. 1 Normal tendons, US appearance. a, b Longitudinal andtransverse US of the extensor carpi ulnaris tendon (arrows). Thetendon is located inside a fibroosseous groove formed by the ulnaand the overlying retinaculum (white arrowheads). In a, US showsthe typical hyperechoic fibrillar pattern (void arrowhead), while inb, a punctiform appearance is evident. c, d Longitudinal US of thequadriceps tendon with MRI correlation. US shows the tendon

(arrows) formed by three juxtaposed laminae (void arrowheads).Accurate technique of examination allows optimal assessment ofits distal insertion into the patella (Pat). A corresponding proton-density fat saturation sagittal MRI image, obtained in the samesubject, confirms the multilayered internal organization of the quad-riceps tendon. (Small asterisk suprapatellar fat pad, large asteriskprefemoral fat)

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tendons are subject to forces that induce their displace-ment. Peritendinous synovial bursae, pouch-like structuresformed by a thin layer of synovium containing a thin filmof synovial fluid, reduce friction between tendons and theadjacent bones during movements.

Microscopic anatomy

From a histological point of view, tendons are formed bya minor (20%) cellular component, the fibroblasts, and alarger component of extracellular matrix mainly madefrom collagen, water, and elastin. Tendon collagen is type Icollagen arranged in longitudinal bundles of fibers groupedto fascicles. The particular arrangement of collagen al-lows good resistance to high tensile load. Endotendineumand peritendineum surround the tendon fibers and are incontinuity with the epitendineum, a dense connective tis-sue layer tightly bound to the tendon surface. Tendons aresparsely vascularized.

Normal US appearance

Longitudinal sonograms of tendons show an internal net-work made up of many fine, tightly packed parallel ech-oes that resemble a fibrillar pattern (Fig. 1). The linearinternal fibrillar echoes correspond not to the tendon bun-dles but to the interfaces between them and the periten-

dineum [15–16]. Transverse images depict tendons ashyperechoic structures that appear as an internal homo-geneous structure made by multiple small echogenic dotspacked together. When examined by US, both in longitu-dinal and transverse planes, tendons show anisotropy—changes in echogenicity depending on the angle of theUS beam. When properly imaged with the US beam per-pendicular to the surface of the tendons, they appear hy-perechoic, whereas if the transducer is also lightly tilted,they appear hypoechoic because of the resulting obliqueincident angle of the beam (Fig. 2) [17]. Anisotropy hasclinical relevance because if tendons are not properly ex-amined, their internal structure cannot be assessed. As aconsequence, tendinopathy may be incorrectly diagnosedin the presence of false hypoechogenicity of an incorrectlyimaged tendon, and a tendinopathy can be confused asnormal anisotropy by an inexperienced sonologist.

Peritendinous structures can also be well demonstratedby US (Fig. 3). The peritenon appears as a hyperechoicline at the superficial and deep aspect of the tendon. Innormal conditions the thin synovial sheath is not detectedeven by high-resolution transducers, and the small amountof fluid can seldom be demonstrated as an anechoiclayer surrounding the tendon. Adjacent synovial bursaecan be detected only by high-frequency transducers ashypoechoic linear fluid collections, while retinacula ap-pear as linear hyperechoic structures overlying tendonsand inserting into bones.

Fig. 2 Tendon anisotropy. a, b Longitudinal US of the quadricepstendon obtained with the knee extended (a) and flexed (b). In a, thetendon appears curvilinear. While the proximal tendon (white arrow)is well imaged, the distal part (void arrow) appears falsely hypo-echoic because of oblique incidence of the US beam. With kneeflexion (b), the quadriceps tendon is straightened and well imagedby the perpendicular US bean. Note how knee flexion allows adetailed assessment of the internal regular hyperechoic structure of

the tendon. (Pat patella) c, d Transverse images of the long head ofthe biceps tendon in a patient with intraarticular shoulder effusion,obtained with the transducer oblique (c) and perpendicular (d) to thetendon. In b, because of anisotropy, the falsely hypoechoic tendon(void arrow), which is surrounded by an anechoic fluid collection(arrowhead), is barely visible. This aspect can mimic a completetear. In d, US depicts the tendon as a well-delimited hyperechoicoval structure.

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In normal conditions, color and power Doppler do notdetect flow signals inside tendons because of the smallvessel size. Sometimes thin vessels can be detected run-ning adjacent to tendons and probably represent vesselsof synovial sheaths or peritenon. No studies have beenpublished in the literature concerning the possibility of vi-sualizing normal tendon vessels by ultrasound contrastmedia.

Ultrasound of tendon rupture

Upper extremity

Tears of the rotator cuff of the shoulder

The rotator cuff of the shoulder consists of the subscapu-laris, supraspinatus, infraspinatus, and teres minor ten-dons. The long head of the biceps tendon runs inside the“rotator cuff interval” located between the supraspinatusand subscapularis tendons and is frequently injured to-gether with the rotator cuff. In the great majority of cases,tendon ruptures are the result of repetitive microtraumaand chronic tendonitis due to impingement of the rotatorcuff against the lower surface of the coracohumeral lig-ament and acromion [18]. Less frequently, a rotator cufftear can result from acute trauma such as a fall on anextended upper arm [19].

The supraspinatus tendon is most commonly involvedin anterosuperior impingement of the shoulder. Becauseof the anatomic location and reduced vascular supply ofits lateral portion, the so-called “critical area,” it is proneto degeneration and tear. The first lesion is local tendon

degeneration, followed by a partial-thickness tear at thelevel of the articular face that, if untreated, can evolveto a full-thickness anterior tear and then complete rupture.Tears to the supraspinatus tendon can later extend pos-teriorly to the infraspinatus tendon or anteriorly to involvethe long head of the biceps tendon and the subscapularistendon [20]. As a result of tears, localized pain, loss offunction, and painful elevation of the arm occur. Clinicalfindings, however, particularly in cases of smaller tearswhen definite loss of function is not present, are nonspe-cific and can result from other disorders, such as tendonitis.Treatment of tendonitis includes rest, physical therapy, andanti-inflammatory drugs, while surgery may be required fortendon tears, depending on the patient’s age, symptoms, andfunctional requirements [21]. An imaging modality is thuscritical to the early detection and accurate assessment ofthe size of a rotator cuff tendon rupture.

US is a reliable and sensitive modality for assessingrotator cuff tears [22–27]. The examination is performedon the seated patient by longitudinal and transverse sono-grams obtained over each tendon and on the biceps ten-don [27]. A standardized examination technique mustalways be deployed in an effort to evaluate all tendons andachieve images that can be easily interpreted and providea basis for subsequent studies. Each tendon is carefullyevaluated from the myotendinous junction to insertioninto bone through transverse and longitudinal images ob-tained in the proper position—that is, one that allows op-timal tendon stretching [27]. In addition, images directedto assessing the biceps tendon and detecting fluid insidethe glenohumeral cavity, subacromial bursa, and acromio-clavicular joint are obtained.

Fig. 3 Peritendinous structures. a Peritenon. Longitudinal US ofthe Achilles tendon shows its normal internal fibrillar appearance(arrow) and the peritenon (arrowheads) appearing as a regularhyperechoic line overlying the posterior and anterior tendon borders.b Retinacula. Transverse images obtained over the anterolateralaspect of the ankle show the four extensor digitorum tendons (blackarrowheads). The extensor retinaculum is imaged as a thin fibrous

band overlying and stabilizing the tendons. c, d Peritendinousbursae. Longitudinal US images and corresponding proton-densityfat saturation sagittal MRI image in a normal subject show thenormal thin retrocalcaneal bursa (arrowheads) located between theanterior aspect of the Achilles tendon (arrow) and the posterior faceof the calcaneum. The bursa appears as a thin hypoechoic structurecontaining a tiny amount of fluid.

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US depicts a partial tear of the supraspinatus tendonas a hypoechoic area located inside the tendon or at itsbursal or articular aspect that is manifested in two per-pendicular planes or as a mixed hypo-hyperechoic arealocated at the level of the critical area (Fig. 4) [26]. Itmust be stressed that differentiation between a partial rup-ture and severe localized degeneration can be difficult andthat frequently a partial tear cannot be definitely affirmedonly on the basis of US appearance. Compared with itsability in diagnosing complete tears, US is less sensitive indetecting partial tears [28]. Complete tears are diagnosedusing different parameters: hypoechoic full-thickness cleftinside the tendon (Fig. 5), detachment of the tendon from

the bone insertion with medial dislocation (Fig. 6), andnonvisualization of the tendon (Fig. 7). Examination dur-ing application of firm pressure with the transducer mustalways be done in an effort to induce shift of the fluidand synovial hypertrophy that can mimic a hypoechoictendon (Fig. 8). Dorsal extension of the tear to the infra-spinatus tendon can be detected by posterior images(Fig. 9) obtained on the sagittal and transverse plane.Because the supraspinatus tendon blends gradually withthe infraspinatus, the two cannot be differentiated by US.By convention, the supraspinatus tendon, evaluated in thesagittal oblique plane, accounts for the first 15 mm of thecuff, starting from the long head of the biceps tendon.

Fig. 4 Supraspinatus tear. Partial tear of the articular aspect. Cor-onal oblique US image (a) with corresponding T1-weighted fatsaturation MR arthrogram correlation (b). US images the tear(arrow) as a hypoechoic cleft located inside the middle third of

the tendon (asterisks). Note that the deep tendon appears retracted(arrowhead) from its insertion into the upper face of the greatertuberosity (GT). In b, note the tear filled by gadolinium.

Fig. 5 Supraspinatus tear. Complete tear at the critical area. Cor-onal oblique (a) and sagittal oblique (b) US images show a full-thickness tear located at critical area of the supraspinatus tendon,approximately 1–2 cm from its insertion into the greater tuberosity

(GT). The tear (arrow) appears as a focal discontinuity of the tendon(asterisk) filled with hypoechoic fluid. Also note bursal flatteningin a.

Fig. 6 Supraspinatus tear.Disinsertion. Coronal oblique(a) and corresponding T1-weighted fat saturation MRarthrogram image (b) depict adisinsertion (arrow) of the su-praspinatus tendon (asterisk)from the greater tuberosity(GT). In a, note the peribursalfat (arrowhead) herniating in-side the superficial part of thetear. In b, the injected gadolin-ium fills the tear.

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Consequently, tears extending posteriorly for more than1.5 cm are believed to involve the infraspinatus tendon[28]. Accurate tear size evaluation is important for mostshoulder surgeons because it can affect choices among lessinvasive arthroscopy, mini-open techniques (small tears),or open repair (larger tears). In complete tears of thesupraspinatus tendon, US allows accurate assessment ofmoderate medial retraction. Unfortunately, more severe

retraction cannot be evaluated because the posteriorshadowing of the acromion does not allow visualizationof the retracted tendon. Because of the absence of theoverlying acromion, the medial retraction of the torninfraspinatus can always be accurately evaluated by US.Tears of the subscapularis tendon are a consequence ofanterior extension and can affect its cranial aspect or thewhole tendon and are usually associated with medial dis-

Fig. 7 Supraspinatus tear. Complete tear with medial retraction ofthe tendon end. Coronal oblique (a) and sagittal oblique (b) USimages and (c) corresponding T1-weighted coronal oblique MRarthrogram. US images the deltoid muscle resting on the upper sur-face (arrowheads) of the greater tuberosity (GT) and humeral head.Note the irregular superior face of the tuberosity related to reactivehyperostosis. A hypoechoic effusion (asterisks) located inside the

subacromial bursa and filling the gap between the retracted ten-don and the greater tuberosity can be appreciated. The retractedsupraspinatus tendon end is no longer evident. (IS infraspinatustendon, BT long head of the biceps tendon) c T1-weighted coronaloblique MR arthrogram shows the retracted supraspinatus lyingunder the acromion.

Fig. 8 Supraspinatus tear. Complete tear. Importance of examina-tion technique. Coronal oblique US image obtained without (a) andwith (b) pressure applied through the transducer and (c) correspond-ing T1-weighted coronal oblique MR arthrogram. a Fluid andsynovial folds within the subacromial bursa mimic the supraspinatus

tendon. b Application of a firm pressure (arrow) on the transducerallows fluid displacement away from the field of view and her-niation of the deltoid muscle, thus confirming a complete tear. c T1-weighted coronal oblique MR arthrogram confirms evident synovialvillosities filling the subacromial bursa.

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location of the long head of the biceps tendon (Fig. 9).Isolated tears of the infraspinatus tendon are very unusu-al, whereas the subscapularis tendon can be the only in-jured tendon when falling on the externally rotated arm.

Associated findings of rotator cuff tears, such as bursalor intraarticular effusions, can also be easily detected byUS and can increase diagnostic accuracy [29]. Fluid in-side the subacromial bursa usually collects in its caudalportion and can be found both in superficial and full-thickness tears. The bursa is best evaluated at the lateralaspect of the shoulder between the supraspinatus tendonand the deltoid muscle [30]. Nevertheless, small amountsof fluid can go unnoticed unless the bursa is examinedat the beginning and at the end of the examination be-cause the different movements required for examiningthe rotator cuff tendons can induce displacement of smallamounts of fluid inside the bursa and allow their identi-fication. When larger effusions are present, they fill thebursa anterior to the biceps groove and must be dif-ferentiated with intraarticular fluid contained within thebiceps tendon sheath. Care must be taken not to applyexcessive pressure with the transducer when examiningbursal effusions in order to avoid displacement of the fluid

and a false negative examination. Moderate synovial hy-pertrophy of the bursa can be seen in chronic rotator cufftears and appears as slight thickening and indistinctnessof the upper supraspinatus border. A glenohumeral ef-fusion when associated when bursal effusion indicates afull-thickness tear. Intraarticular effusions are best detect-ed at the biceps recess that surrounds the biceps tendonin the humeral sulcus and inside the axillary recess, whichis best imaged on transverse posterior scans. In a studyassessing the value of associated intraarticular and bursaleffusions with rotator cuff tears, joint effusions had asensitivity of 22%, specificity of 79%, and positive pre-dictive value of 60%. Effusions located both inside thebursal and glenohumeral joint had a sensitivity of 22%,specificity of 99%, and positive predictive value of 95%,and were present in 1.7% of asymptomatic shoulder cases[31].

Irregularities of the greater tuberosity are associated withrotator cuff tears [32]. An irregular appearance was foundin 90% of rotator cuff tears and in only 11% of nor-mal subjects. Irregularity was present in 75% of tears. Anormal greater tuberosity was associated with 96% ofnormal cuffs [32]. Color and power Doppler studies are

Fig. 9 Rotator cuff tear. Posterior extension to the infraspinatustendon. Transverse US image obtained (a) at the level of the infra-spinatus tendon and (b) more inferiorly on the teres minor tendon.c Sagittal oblique sonogram and (d) corresponding T1-weighted sagittaloblique MR arthrogram. a The infraspinatus tendon (arrow) appearstorn and retracted at the level of the posterior glenoid labrum(arrowhead). A fluid effusion (asterisk) located inside the subacro-mial bursa and communicating with the joint cavity through thetendon gap appears as a hypoechoic area lying between the deltoid

and the humeral head (HH). (G posterior aspect of the glenoid)b The normal teres minor tendon (white arrow) is located betweenthe deltoid and the HH. c Sagittal image shows the intact teresminor (arrow) and fluid (asterisk) replacing the avulsed infra-spinatus tendon. d Corresponding T1-weighted sagittal oblique MRarthrogram confirms the complete tear and medial retraction of theinfraspinatus tendon. Note fluid (asterisk) located inside the su-praspinatus defect.

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rarely used for assessing shoulder tendon tears becausethey do not add significant information to conventionalUS. Contrast ultrasound medium has not yet been eval-uated in this field.

The overall sensitivity and specificity of US for as-sessing rotator cuff tears varies in the literature from 50%to 100%. Not surprisingly, the sensitivity is greater forfull-thickness tears (94–100%) than for partial-thicknesstears (93–96%) [26, 32]. This variability seems to resultfrom the intrinsic operator dependence of the techniqueor/and the quality of the equipment used. Broad-bandelectronic probes and modern software have markedlyimproved US capabilities, and experienced sonologistsusing high-quality equipment achieve sensitivity and spec-ificity for rotation cuff tears similar to those of magneticresonance imaging (MRI) and improve detectability andassessment of rotator cuff tears with respect to physi-cal examination [33]. When performed by experiencedsonologists, US of the rotator cuff has a low level ofinterobserver variability for rotator cuff tears [34]. US isless accurate than MRI for evaluating the degree of fatinfiltration of the cuff muscles and in accurately assessingtendon medial retraction when this is greater than 3 cm[35] (Fig. 10). However, US has produced significantlyhigher patient satisfaction compared with MRI [36].

We believe the first imaging modalities to be obtainedin patients with clinical suspicion of rotator cuff tearsshould be standard radiographs and US. Anteroposteriorradiographs with different rotations of the arm (internal,neutral, and external) and Neer view can detect joint andbone lesions and can evaluate the shape of the acromionthat is related to rotator cuff tears. US allows an accurateassessment of tendon structure and articular or periarticulareffusions and is well accepted by patients. When surgicalrepair is warranted, MRI or MRI arthrography may bedone for more objective tear demonstration, accurate eval-uation of tendon retraction, and detection of muscle atrophyand internal fat degeneration relevant to the postsurgicaloutcome.

US assessment of the postoperative rotator cuff is oftendifficult because of the frequently limited range of move-ment of the shoulder and thinning and heterogeneous ap-pearance of the repaired tendon. Before performing a studyof the operated cuff, every effort must be made to learnthe details of the surgical procedure. Obviously, in the eval-uation of re-tears, it is essential to know whether the sur-geon performed a reinsertion of the avulsed cuff into thegreater tuberosity or only acromioplasty and bursectomy.

Tears of the long head of the biceps tendon

Tears of the long head of the biceps tendon result mainlyas a complication of a supraspinatus injury. The tendonusually ruptures at the lateral intraarticular portion. Clin-ically, partial tears are difficult to differentiate from ten-

donitis or partial rupture affecting the anterior part of thesupraspinatus tendon. Complete tears present as a lump atthe level of the antecubital fossa that corresponds to thedistally retracted muscle belly, the so-called Popeye sign,and reduced strength of elbow flexion and hand supi-nation. Patients with acute ruptures present with ecchymo-sis of the anterior aspect of the arm that, together with thedistal mass, allows a definite diagnosis without the need for

Fig. 10 Rotator cuff muscle fat degeneration. Sagittal US imageobtained over the posterior aspect of the scapula (a) and transversesonograms obtained (b) at the level of the infraspinatus (IS) and (c)teres minor (TM) muscle in a patient with complete tear of theinfraspinatus tendon. Note the hyperechoic appearance of the ISsecondary to fat infiltration. The TM muscle presents a normalinternal appearance, similar to that of the overlying deltoid muscle.

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an imaging technique. Nevertheless, in obese or unfit sub-jects with little muscle bulk, the retracted muscle cannot bepalpated, and a complete tear can be difficult to prove. USis an accurate modality for investigating the long head ofthe biceps tendon [37, 38].

In partial tears the tendon appears swollen and hypo-echoic, particularly at the level of the cranial biceps sulcus(Fig. 11). Frequently it appears subluxed medially andsurrounded by a fluid effusion. Differentiation betweentendinopathy and a partial tear is not feasible on the USfindings alone and requires correlation with clinical data.In complete tears, due to the distal retraction of the muscle,the tendon is no longer visualized inside the sulcus, andin acute cases this is filled with a hypoechoic effusion(Fig. 12). An empty sulcus is not synonymous with a com-plete tendon tear, as it can also be seen when the tendondislocates medially, secondary to subscapularis tendonruptures or lesions of the rotator cuff interval [37–41].

Dislocation of the tendon deep to the subscapularis in-dicates a subscapularis tear, whereas superficial dislocationindicates transverse ligament or rotator cuff interval tear.Instability of the long head of the biceps tendon can beeasily diagnosed. Using distal transverse images, a normalmyotendinous distal junction is identified, and then theintact tendon can be easily followed upward by trans-verse images to demonstrate its intraarticular displace-ment. Dynamic US examination performed by transversesonograms obtained during external rotation of the armcan be useful in demonstrating intermittent tendon in-stability [42]. In chronic tears, the fibrous reaction anddebris within the sulcus can mimic an intact tendon.Detection of the retracted globular muscle belly allowsthe diagnosis of complete rupture. The internal appear-ance of the retracted muscle varies depending on the ageof the tear. In acute ruptures, transverse sonograms showa similar echogenicity of both the long and short head,

Fig. 11 Long head bicepstendon tears. Partial-thicknesstear. Transverse (a) and longi-tudinal (b) images obtained overthe long head biceps tendon.The proximal part of the tendonappears thickened and irregu-larly hypoechoic (white arrows),whereas the distal portion (voidarrow) is normal. The tendonsheath is filled by a smallamount of fluid and synovialfolds (void arrowheads).

Fig. 12 Long head bicepstendon tears. Acute completetear. Transverse proximal(a), distal (b), and longitudinal(c) US images. d CorrespondingT1-weighted transverse MRarthrogram. In a, no tendon canbe detected. The biceps recess isfilled by a hypoanechoic fluidcollection (arrowhead) compat-ible with a hematoma. A moredistal transverse scan (b) showsthe hypoechoic distally retractedtendon end (arrow) surroundedby fluid (arrowhead). c Thelongitudinal image depicts theglobular appearance of the dis-tally retracted tendon and thefluid surrounding it. d MRarthrogram confirms US find-ings showing an empty recess.

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whereas in chronic ruptures the long head appears hyper-echoic because of fat infiltration.

Tears of the distal tendon of the biceps

The distal tendon of the biceps originates from converg-ing of the lateral and medial heads at the level of thedistal humerus. It crosses the anterior region of the elbow,running in the antecubital fossa to insert in the radialtuberosity. An expansion of the distal muscle fascia, thelacertus fibrosus, attaches in the forearm fascia and actsas a support in elbow flexion. Partial or complete rup-tures of the distal biceps tendon result from an excessivetension force applied to a flexed elbow [43], producinga sharp, localized pain. A distal palpable defect, a prox-imal bulge related to the retracted muscle, and diminishedstrength of elbow flexion are clinical findings highly sug-gestive of a complete tear. Nevertheless, an intact lacertusfibrosus can prevent proximal retraction of the muscle andmake clinical diagnosis more difficult. Partial tears aremore difficult to assess clinically, and imaging is requiredwhen marked local edema limits physical examination orwhen the uninjured lacertus fibrosus permits an activeflexion despite a complete distal tendon tear. In mostcomplete tears, US demonstrates the proximally retractedtendon inside the subcutaneous tissues of the antecubitalfossa, superficial to the brachialis muscle [44, 45]. In acutelesions, a local effusion frequently outlines the proximaltendon’s end (Fig. 13). The contrast between the retractedtendon and the anechoic collection facilitates recognizingthe tendon discontinuity. An accurate investigation tech-nique is necessary to diagnose a complete tear. The elbowshould be extended and supinated as much as possible,and oblique sagittal and transverse images should be un-dertaken. In the rare instances in which tendon retractionis limited by a continuous lacertus fibrosus, MRI willconfirm the US findings. Partial tears of the tendon ap-pear continuous but swollen and irregularly hypoechoic.MRI seems more accurate than US in depicting intra-tendinous changes found in partial tears [46].

Tears of the triceps tendon

Triceps tendon tears are far less common than bicepsruptures and represent only 2% of all tendon ruptures[47]. The clinical presentation is swelling of the distalposterior aspect of the arm and reduced or absent activeextension of the elbow. A gap at the level of the distaltendon can be felt. The pathomechanism of tears mostlyinvolves a forceful contraction of the triceps muscle suchas during a fall into an outstretched hand, although directlocal trauma can also lead to tendon tear [48]. Usually thetendon disruption is at the level of the distal bone insertion.Myotendinous junction tears can be rarely observed. Apeculiar form of tear is an avulsion fracture of the tendoninsertion into the olecranon. In this case, standard lateralradiographs display a calcified lesion retracted toward thehumeral head, usually lying 2–3 cm from the olecranon tip.Analysis of the structure reveals an internal trabecularpattern that is helpful in differentiating it from an amor-phous soft tissue calcification. US can detect a tricepstendon tear and accurately locate the retracted tendon end.In cases of avulsion fracture, the bone fragment, readilyapparent on plain radiographs, can be demonstrated as ahyperechoic lesion with posterior artifact found at the distalend of the triceps tendon. A hematoma usually surroundsthe tendon tear and facilitates its detection. The mostuseful application of US in triceps tendon tears is to dif-ferentiate a complete from a partial tear by visualizing thenumber of fibers injured. Unlike MRI, US can be per-formed with the patient in a comfortable sitting positionwith the elbow in a painless position.

Tears of the wrist and hand tendons

Tears of the wrist and hand tendons mainly follow openinjury or rheumatoid involvement of the tendon sheath.Traumatic ruptures are easily diagnosed by accurate in-spection and debridement of the cutaneous lesions. Closedruptures can be seen in local blunt trauma but are far morecommonly the result of chronic inflammation and weak-

Fig. 13 Distal biceps tendon complete tear. Acute complete tear.Longitudinal (a) and transverse (b) images. In the transverse image,note the proximally retracted tendon (arrows) and the peritendinoushematoma (arrowhead). Assessment in the longitudinal plane depicts

the complete interruption of the tendon fibers, the retracted torntendon (white arrow), and the distal hematoma (arrowhead). Notethe wrinkled appearance of the proximal tendon (void arrow).

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ening in inflammatory disorders that affect either thejoints or the tendon sheath. In rheumatoid arthritis (RA),hypertrophy of the synovium of the tendon sheath leadsto tendon damage because of a proteolytic effect of thepannus. In addition, erosion of bone ends and ligamentsand retinacula laxity or tears allow joint subluxation withresultant anomalous friction on the adjacent tendons. As aresult of both chemical and mechanical stresses, progres-sive tendon thinning may be followed by complete rup-ture even after trivial trauma. The most commonly affectedwrist tendons are the extensors of the 4th and 5th fingersand the extensor carpi ulnaris. All of these tendons aresubject to chronic friction over the ulnar head, which inRA is frequently subluxed dorsally as a consequence oftriangular cartilage rupture.

Although clinical examination reveals tears of fingertendons due to a failure of flexion or extension of theaffected finger, the diagnosis can be more difficult if a wristtendon is affected. The clinical detection of rupture of oneof the two extensor carpi radialis tendons may be difficultdue to action of the uninvolved tendon (Fig. 14). Traumaticdisruption of the peritendinous structure can be alsodetected by US. Complete tears of the annular pulleys ofthe fingers can be easily diagnosed by showing the plantarbowstringing of the two flexor tendons [49–51].

The main utility of US in hand and wrist tendon tears isfor assessing partial tears and locating the retracted stumpin complete lesions [52]. Detection of partial tears in RA isimportant because it can indicate the need for early te-nosynovectomy to prevent complete ruptures. Partial tears

Fig. 14 Extensor carpi ulnaris longitudinal tear. Transverse andlongitudinal US and MRI images obtained at the level of the 6thextensor compartment of the wrist in a patient affected by se-ropositive rheumatoid arthritis. a, b Longitudinal and color Dopplertransverse US images. Sonograms show the irregular tendon (whitearrows) surrounded by the hypertrophic hypoechoic pannus (void

arrows). In b, note the flow signals (void arrowheads) located insidethe inflamed visceral and parietal synovial sheath and a partial tear(white arrowhead). (Tri triquetrum) c, d Corresponding T1-weight-ed postgadolinium MRI images confirm contrast enhancement of thehypertrophic synovial membrane (void arrows) and the tendonpartial tear (white arrowhead). (Tri triquetrum)

Fig. 15 Extensor carpi radialis longus complete tear. Transverseimages obtained at the level of the 2nd extensor compartment of thewrist. a Acute complete tear. b Normal contralateral wrist. In a, theextensor carpi radialis longus (black arrow) cannot be detectedbecause of proximally retraction following a complete tear. Note thefibrous tissue replacing the torn tendon (void arrowhead) and the

subtle subluxation of the normal extensor carpi radialis brevis (whitearrow). The retinaculum appears hypoechoic and thickened (blackarrowheads). In b, note the normal extensor carpi radialis longusand brevis tendons retained against the radius by the dorsal retinaculum(white arrowheads).

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appear on US as localized swelling or thinning of thetendon that appears heterogeneous and hypoechoic (Fig. 15).The presence of adhesion to the surrounding tissues canbe demonstrated by dynamic US. Examination performedat the level of the distal forearm in the complete tearallows detection of the retracted tendon end as a hypo-echoic mass. Marking the skin at the level of the prox-imal tendon can be useful in the preoperative setting andcan limit the size of the surgical incision.

In conclusion, tendon tears of the upper extremity arecommon lesions that deserve early and accurate evalua-tion in order to decrease secondary morbidity and chronicsequelae. Physical examination is the mainstay of diag-

nosis but is often limited by local pain and swelling andcan be inaccurate in differentiating partial from completetears. US is a low-cost, readily available, noninvasive, anddynamic modality that allows precise assessment of ten-don tears of the upper extremity. A good knowledge ofnormal anatomy, examination technique, and correlationwith clinical findings are prerequisites for successful USassessment. US is the first-line imaging technique whena tendon tear is suspected clinically, and when under-taken by an experienced sonologist using state-of-the-artequipment, it allows an accurate diagnosis and stagingof the lesion in most cases.

References

1. Kainberger F, Mittermaier F, Seidl G,et al. Imaging of tendons: adaptation,degeneration, rupture. Eur J Radiol1997; 25:209–222.

2. Potasman I, Bassan HM. Multipletendon rupture in systemic lupuserythematosus: case report and reviewof the literature. Ann Rheum Dis 1984;43:347–349.

3. Levy M, Seelenfreund M, Maor P,Fried A, Lurie M. Bilateral spontaneousand simultaneous rupture of thequadriceps tendon in gout. J BoneJ Surg (Br) 1971; 53:510–513.

4. Peiro A, Ferrandis R, Garcia L.Alcazar E. Simultaneous andspontaneous bilateral rupture of thepatellar tendon in rheumatoid arthritis:a case report. Acta Orthop Scand 1975;46:700–703.

5. Barash E, Lombardi L, Arena L,Epstein E. MRI evaluation of bilateralquadriceps tendon rupture in a patientwith secondary hyperparathyroidism:implication for diagnosis and therapy.Comput Med Imaging Graph 1989;5:407.

6. Lotem N, Robson MD, Rosenfeld GD.Spontaneous rupture of the quadricepstendon in patients on chronichaemodialysis. Ann Rheum Dis 1974;33:428–429.

7. Fornage BD, Rifkin MD. Ultrasoundexamination of tendons. Radiol ClinNorth Am 1988; 6:87.

8. van Holsbeeck MT, Introcaso JH.Sonography of tendons. In:van Holsbeeck MT, Introcaso JH (ed)Musculoskeletal ultrasound. St. Louis:Mosby, 1991:57

9. Chhem RK, Kaplan PA, Dussault RG.Ultrasonography of the musculoskeletalsystem. Radiol Clin North Am 1994;32:275.

10. Jacobson JA, van Holsbeeck MT.Musculoskeletal ultrasonography.Orth Clin North Am 1998; 29:135.

11. Fessel DP, Vanderschueren GM,Jacobson JA, et al. US of the ankle:technique, anatomy, and diagnosis ofpathologic conditions. Radiographics1998; 18:325.

12. van Holsbeeck MT, Introcaso JH.Musculoskeletal ultrasonography.Rad Clin North Am 1992; 30:907.

13. O’Brien M. Functional anatomy andphysiology of tendons. Clin SportsMed 1992; 11:505.

14. Bertolotto M, Perrone R, Martinoli C,et al. High resolution ultrasoundanatomy of normal Achilles tendon.Br J Radiol 1995; 68:986.

15. Martinoli C, Bianchi S, Derchi LE.Ultrasound of tendon and nerves.Radiol Clin North Am 1999; 37:691–711.

16. Martinoli C, Derchi LE, Pastorino C,et al. Analysis of echotexture oftendons with US. Radiology 1993;186:839.

17. Fornage BD. The hypoechoic normaltendon. A pitfall. J Ultrasound Med,1987; 6:19–22.

18. Neer CS. Impingement lesions ClinOrthop 1983; 173:70–77.

19. Peetrons P, Lemone M, Jeanmart J.Echographie et pathologie traumatiquede l’epaule: coiffe des rotateurs ettendon de la longue portion du biceps.Radiologie J.CEPUR 1990; 10:177–181.

20. Codman EA. The shoulder, 2nd edn.Boston: Thomas Todd, 1934.

21. Neer CS 2nd. Anterior acromioplastyfor the chronic impingement syndromein the shoulder: a preliminary report.J Bone Joint Surg Am 1972; 54:41–50.

22. Soble MJ, Kaje AD, Guay RC.Rotator cuff tear: clinical experiencewith sonographic detection. Radiology1989; 173:319–321.

23. Crass JR, Craig EV, Feinberg SB.Ultrasonography of rotator cuff tears:a review of 500 diagnostic studies.J Clin Ultrasound 1988; 16:313–327.

24. Farin PU, Jaroma H, Harju A et al.Shoulder impingement syndrome:sonographic evaluation. Radiology1990; 176:845–849.

25. Middleton WD. Ultrasonography of theshoulder. Radiol Clin North Am 1992;30:927–940.

26. van Holsbeeck MT, Kolowich PA,Eyler WR et al. US depiction of partialthickness tear of the rotator cuff.Radiology 1995; 197:443–446.

27. Teefey SA, Middleton WD, YamaguchiK. Shoulder sonography. State of theart. Radiol Clin North Am 1999;37:767–785.

28. Teefey SA, Hasan SA, Middleton Wet al. Ultrasonography of the rotatorcuff. A comparison of ultrasonographicand arthroscopic findings in one hun-dred consecutive cases. J Bone JointSurg Am 2000; 82:498–504.

29. Jacobson J, Lancaster S, Prasad A et al.Full-thickness and partial-thicknesssupraspinatus tendon tears : value ofUS signs in diagnosis. Radiology 2004;230:234–242.

30. van Holsbeeck M, Strouse PJ.Sonography of the shoulder: evaluationof the subacromial-subdeltoid bursa.AJR Am J Roentgenol 1993; 160:561–564.

31. Hollister MS, Mack LA, Patten RMet al. Association of sonographicallydetected subacromial/subdeltoid bursaleffusion and intraarticular fluid withrotator cuff tear. AJR Am J Roentgenol1995; 165:605–608.

32. Wohlwend JR, van Holsbeeck M,Craig J. The association betweenirregular greater tuberosities and rotatorcuff tears: a sonographic study. AJRAm J Roentgenol 1998; 171:229–233.

511

33. Bryant L et al. A comparison of clinicalestimation, ultrasonography, magneticresonance imaging, and arthroscopy indetermining the size of rotator cufftears. J Shoulder Elbow Surg. 2002;11:219–224.

34. Middleton WD, Teefey SA,Yamaguchi K. Sonography of therotator cuff: analysis of interobservervariability. AJR Am J Roentgenol2004;183:1465–1468.

35. Kluger R, Mayrhofer R, Kroner A et al.Sonographic versus magneticresonance arthrographic evaluation offull-thickness rotator cuff tears inmillimeters. J Shoulder Elbow Surg2003; 12:110–116.

36. Middleton WD, Payne WT, Teefey SAet al. Sonography and MRI of theshoulder: comparison of patientsatisfaction. AJR Am J Roentgenol2004; 183:1449–1452.

37. Middleton WD, Reinus WR, Totty WGet al. US of the biceps tendonapparatus. Radiology 1985; 157:211

38. Ptasznik R, Hennessy O. Abnormalitiesof the biceps tendon of the shoulder:sonographic findings. AJR AmJ Roentgenol 1995; 164:409–414

39. Gandolfo N, Bianchi S, Martinoli Cet al. [Long biceps brachii instability.Role of ultrasonography]. Radiol Med1998; 96:18–22.

40. Prato N, Derchi LE, Martinoli C. Casereport: sonographic diagnosis of bicepstendon dislocation. Clin Radiol 1996;51:737–739.

41. Patton WC, McCluskey III. Bicepstendinitis and subluxation. ClinicsSports Med 2001; 20:505–529.

42. Farin PU, Jaroma H, Harju A et al.Medial displacement of the bicepsbrachii tendon: evaluation withdynamic sonography during maximalexternal shoulder rotation. Radiology1995; 195:845–848.

43. Agins HJ, Chess JL, Hoekstra DV et al.Rupture of the distal insertion of thebiceps brachii tendon. Clin Orthop1988; 234:34–38.

44. Miller T, Adler RS. Sonography oftears of the distal biceps tendon. AJRAm J Roentgenol 2000; 175:1081–1086.

45. Lozano-V, Alonso-P. Sonographicdetection of the distal biceps tendonrupture. J Ultrasound Med 1995;14:389–391.

46. Falchook FS, Zlatkin MB, Erbacher GEet al. Rupture of the distal bicepstendon: evaluation with MR imaging.Radiology 1994; 190:659–663.

47. Anzel SH, Covey KW, Weinr AD et al.Disruption of muscles and tendons: ananalysis of 1,041 cases Surgery 1959;45:406–414.

48. Rajasekhar C, Kakarkapudi TK,Bhrama MS. Avulsion of the tricepstendon. Emerg Med J 2002; 19:271–272.

49. Martinoli C, Bianchi S, Derchi L,Garcia J. Sonographic evaluation ofdigital annular pulleys tears. SkeletalRadiol 2000; 29:387–391.

50. Hauger O, Chung CB, Lektrakul Net al. Pulley system in the fingers:normal anatomy and simulated lesionsin cadavers at MR imaging, CT and USwith and without contrast materialdistension of the tendon sheath.Radiology 2000; 217:201–212.

51. Klauser A, Frauscher F, Bodner G et al.Finger pulley injuries in extreme rockclimbers: depiction with dynamic US.Radiology 2002; 222:755–761.

52. Bianchi S, Martinoli C, Abdelwahab IF.High resolution ultrasound of the handand wrist. Review article. SkeletalRadiol 1999; 28:121–129.

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