outcomes and complications of extension of previous long fusion to the sacro-pelvis: is an anterior...

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Outcomes and Complications of Extension of Previous Long Fusion to the Sacro-Pelvis:Is an Anterior Approach Necessary?Kai-Ming G. Fu1, Justin S. Smith2, Douglas C. Burton3, Christopher I. Shaffrey2, Oheneba Boachie-Adjei4,

Brandon Carlson3, Frank J. Schwab5, Virginie Lafage5, Richard Hostin6, Shay Bess7, Behrooz A. Akbarnia8,

reg Mundis8, Eric Klineberg9, Munish Gupta9, and the International Spine Study Group

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NTRODUCTION

ith advances in spinal instrumentation,pine surgeons have been able to treat anncreasing array of spinal disease. However,he durability of spinal fusion operationsas been an area of concern, especially in

hose patients initially treated as adoles-ents or young adults. It is well recognizedhat a subset of patients treated for scoliosisresent later in life with evidence of painfulegeneration below long-segment fusions

� Complications� Deformity� Iliac screws� Pedicle subtraction osteotomy� Revision� Sacro-pelvic instrumentation� Spine� Surgery

Abbreviations and AcronymsAPSF: Anterior-posterior spinal fusionBMI: Body mass indexCT: Computed tomographyPSF: Posterior-only spinal fusionPSO: Pedicle subtraction osteotomySPO: Smith-Peterson osteotomySRS: Scoliosis Research SocietySVA: Sagittal vertical axis

From the 1Department of Neurosurgery, WeillCornell Medical College, New York, New York;

2Neurological Surgery, University of Virginia,harlottesville, Virginia; 3Orthopaedic Surgery, University ofansas Medical Center, Kansas City, Kansas; 4Orthopaedicurgery, Hospital for Special Surgery, New York, Nework; 5New York University Hospital for Joint Diseases,ew York, New York; 6Baylor Scoliosis Center, Plano,

Texas; 7Orthopaedic Surgery, Rocky Mountain Hospital forhildren, Denver, Colorado; 8San Diego Center for Spinal

Disorders, La Jolla, California; and 9Orthopaedic Surgery,niversity of California–Davis, Sacramento, California, USA

o whom correspondence should be addressed:ustin S. Smith, M.D., Ph.D. [E-mail: jss7f@virginia.edu]

itation: World Neurosurg. (2013) 79, 1:177-181.ttp://dx.doi.org/10.1016/j.wneu.2012.06.016

ournal homepage: www.WORLDNEUROSURGERY.org

vailable online: www.sciencedirect.com

878-8750/$ - see front matter © 2013 Elsevier Inc.ll rights reserved.

nding in the distal lumbar spine. Manifes- (

WORLD NEUROSURGERY 79 [1]: 177-181

ations of this degeneration include steno-is, listhesis, and loss of lumbar lordosisith resultant negative effects on global

agittal alignment (5, 6, 12, 14). Revisionurgery after long fusions is therefore notnfrequent (15).

Although there are multiple studies ad-ressing pelvic fixation and its benefits,uch as decreased rates of pseudarthrosis

extension of the fusion to the sacro-poutcomes and complications of theserevision was performed using a posteanterior-posterior spinal fusion (APSF

� METHODS: A retrospective, multicewith a history of prior spinal fusion fodistal lumbar spine requiring extensioiliac fixation in all cases), with minPatients were stratified based on appedicle subtraction osteotomy (PSO).with an anterior interbody fusion donpatients in the APSF group all haapproaches. Clinical outcomes were(SRS-22) questionnaire.

� RESULTS: Between 1995 and 2006,nclusion criteria, with a mean follow-emographic, preoperative, operativend follow-up results were similar b

groups. The APSF group had more cogreater number of pseudarthrosis (4 ofthese differences did not reach statisPSO (n � 13) had greater sagittal verti.04) compared with patients not treat

ifferences in complication rates or foPSO was performed (P > .05).

CONCLUSIONS: Among adults witxtension to the sacro-pelvis, PSF prutcomes equivalent to APSF, whereaesulted in greater sagittal plane coomplication rates.

10, 11, 13, 17), few studies have specifically p

, JANUARY 2013 ww

valuated the extension of previous long fu-ions to the sacrum and pelvis (7, 9, 12).atients requiring extension to the sacro-elvis often need challenging revision sur-eries. Previous investigators have recom-ended combined anterior and posterior

nstrumented fusions coupled with osteot-mies to address degenerative deformitynd loss of lordosis (12). However, these

s. Our objective was to evaluate theents, stratified based on whether theonly spinal fusion (PSF) or combined

evaluation of adults (>18 years old)oliosis (>4 levels) terminating in thefusion to the sacro-pelvis (including

m 2-year follow-up, was performed.ch (APSF vs. PSF) and inclusion ofPSF group included patients treatedough a posterior approach, whereas

oth anterior and posterior surgicald on the Scoliosis Research Society

patients (mean age � 49 years) metf 41.9 months (range 24 to 135 months).

postoperative radiographic, SRS-22,en APSF (n � 30) and PSF (n � 15)ications (13 of 30 vs. 3 of 15) and a. 0 of 15) than the PSF group; however,significance. Patients treated with axis correction (7.7 cm vs. 2.2 cm; P �ith a PSO (n � 32). There were no

-up SRS-22 scores based on whether

eviously treated scoliosis requiringced radiographic fusion and clinicalmplication rates may be lower. PSO

tion, without an increase in overall

� BACKGROUND: Patients with previous multilevel spinal fusion may requireelvipatirior-).

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rocedures have been associated with high

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complication rates, including pseudarthro-sis rates that approach 40% (9).

This study seeks to add to the under-standing of best practice approaches to pa-tients requiring extension of long-segmentlumbar fusion to the pelvis by evaluating theefficacy and morbidity of different surgicalapproaches. In addition, comparisons ofclinical, operative, and radiographic out-comes were performed between patientstreated with and without pedicle subtrac-tion osteotomy (PSO).

MATERIALS AND METHODS

This study was conducted through the In-ternational Spine Study Group, a multi-center group consisting of 11 sites at whichcomplex adult spinal deformity surgery iscommonly performed. Five sites from theInternational Spine Study Group partici-pated in the present study by contributingconsecutive cases of long-segment poste-rior thoracolumbar fusions (�4 levels) forspinal deformity treatment that did not in-clude sacral or pelvic fixation at the time ofthe primary procedure but were later revisedto include pelvic fixation. Institutional re-view board approval was obtained at eachstudy site before initiation of the presentstudy.

The present study was a retrospective co-hort analysis. Inclusion criteria were: age�18 years; history of multilevel (�4 levels)spinal arthrodesis for deformity with distalextension to L3, L4, or L5; subsequent ex-tension of this prior fusion to the sacro-pelvis (including iliac screws) between theyears 1995 and 2006; and minimum 2-yearclinical and radiographic follow-up. Pa-tients were excluded if spinal fusion hadbeen performed for neuromuscular defor-mity, tumor, or infection. Cases were iden-tified based on surgeon case logs, and pre-operative and postoperative clinical recordsand radiographs were reviewed for data ex-traction.

Patients were divided into combined an-terior-posterior spinal fusion (APSF) andposterior-only spinal fusion (PSF) groups.The PSF group included patients treatedwith an anterior interbody fusion donethrough a posterior approach, whereas pa-tients in the APSF group all had both ante-rior and posterior surgical approaches. Pa-tients treated with a PSO were also

178 www.SCIENCEDIRECT.com

ormed. Comparisons were made withhose patients not receiving a PSO but with areoperative sagittal vertical axis (SVA) �5m. Posterior lumbosacral instrumentationncluded standard pedicle screw fixation as

ell as hook-screw constructs. Iliac fixationas used in all cases. Revision graft mate-

ial varied, but generally consisted of localutograft, morselized allograft, and inome cases iliac crest. Interbody supportaterials also varied, and included femoral

ing allograft, carbon fiber cages, andarms cages.Data collected included intraoperative

arameters, preoperative and postoperativeadiographic data (including SVA, coronallignment, Cobb angle, lumbar lordosis,nd thoracic kyphosis), health-related qual-ty of life information (Scoliosis Researchociety [SRS-22]), and perioperative andostoperative complications. Informationn gender, age, and body mass index (BMI)as also recorded from the time of revision

urgery. Follow-up radiographic and SRS-22ata were gathered at last follow-up at a min-

mum of 2 years after revision.Pseudarthrosis was determined based on a

ombinationofplainradiographicimagingandomputed tomography (CT) imaging. Over theinimum2-yearfollow-upperiod,anyevidence

Figure 1. (A) Lateral full-length radiolong-segment thoracolumbar fusiodegeneration at the caudal aspectradiograph of the same patient aftthe fusion to the sacro-pelvis usin

f screw halos, instrumentation failure, or ab-

WORLD NEUROSURGERY, http://d

ormal motion on dynamic plain radiographsas further investigated with CT imaging.ased on CT imaging, lack of evidence of bonyridging across the vertebral level was classifieds pseudarthrosis.

Descriptive statistics were performed toetermine means, medians, and standardeviations. Comparisons between indepen-ent groups were performed using Wil-oxon rank-sum tests. Comparisons of cat-gorical variables between the groups wereerformed with Fisher exact tests. Analysesere performed using SPSS statistical soft-are (SPSS Inc., Chicago, Illinois, USA).ignificance was set at P � .05.

RESULTS

Of the 55 consecutive patients identified, 45(82%) had more than 2-year radiographic fol-low-up and were included in this study. Thirty-six (80%) of the 45 patients had more than2-year SRS-22 scores. The mean length of fol-low-up was 42 months (range 24 to 135months).Thirty-nine(87%)ofthepatientswerewomen. The mean patient age was 49.5 years(SD 11.7 years, range 21 to 73 years). The meanBMIwas26.5(SD6.1,range17.4to44.3).Thirtypatients received APSF, and 15 patients received

of an adult patient with priorcoliosis presenting with painfulfusion. (B) Lateral full-length

ision that included extension ofsterior-only approach.

graphn for sof theer rev

PSF only. Of the patients in the APSF group, 19

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underwent both anterior and posterior proce-duresinasinglestageand11underwentanteriorandposteriorproceduresinseparatestagesdur-ing the same hospitalization. In addition toplacement of anterior interbody support at L5-S1, anterior grafts were placed at L4-5 in 16 pa-tients and at L3-4 in two patients. Ten of 15 PSFpatients (67%) received posterior interbody fu-sion. The numbers of posterior spinal fusionlevels were similar for APSF and PSF (13.3 vs.12.6, respectively; P� .8). Five (33%) patients inthe PSF group and eight (27%) patients in theAPSF group were treated with a PSO(P � .7). Figure 1 demonstrates an example of a

atient requiring sacro-pelvic extension of arior long-segment thoracolumbar fusion forcoliosis.

There were no statistically significant differ-nces between the APSF and PSF groups inerms of preoperative thoracic and thoracolum-ar Cobb angles, coronal alignment, SVA, lum-ar lordosis, and thoracic kyphosis (Table 1).atients in the two groups also did not differtatistically in terms of age (52.4 vs. 48.0; P �

.25) or BMI (24.4 vs. 27.6; P � .12). Patientstreated with a PSO had similar preoperative ra-diographic measurements as those not treatedwith a PSO (Table2). The most common level atwhich PSO was performed was L3 (46%), fol-lowed by L4 (38%) and by L2 (16%). Althoughthere was a trend toward higher preoperative

Table 1. Preoperative Radiographic Mea

ThoracicAngle

Posterior-only spinal fusion (n � 15) 34.7 (20

Combined anterior/posterior spinalfusion (n � 30)

34.1 (13

P values 0.9

Data presented as mean (standard deviation).

Table 2. Preoperative Radiographic Meathe Surgical Procedure

Thoracic CobbAngle

ThorCob

PSO (n � 13) 32.4 (15.5) 30

No PSO (n � 32) 35.1 (16.9) 38

P values 0.63

Data presented as mean (standard deviation).

WORLD NEUROSURGERY 79 [1]: 177-181

VA in those treated with a PSO (9.7 cm) vs.hose not treated with a PSO (5.6 cm), this wasot statistically significant (P � .052).

Patients in the APSF and PSF groups hadimilar radiographic parameters at last fol-ow-up, including coronal alignment (PSF.2 cm vs. APSF �0.6 cm; P � .36), and SVAPSF 4.7 cm vs. APSF 2.1cm; P � .21; Table). SRS-22 total scores at last follow-upere similar between the APSF and PSFroups (3.64 vs. 3.67; P � .9).

Patients treated with a PSO had greater cor-rection in lumbar lordosis (22.5° vs. 11.1°; P �.041) and greater correction of SVA (7.7 cm vs.2.2 cm; P � .048), compared with patients nottreated with a PSO (Table 4). SVA at last fol-low-up was similar between patients treatedwithorwithoutaPSO(1.7cmvs.3.4cm,respec-tively;P� .30).Inaddition,SRS-22scoresatlastfollow-up did not differ significantly based onwhether a PSO was performed (3.69 vs. 3.64;P � .87).

A subanalysis of the 13 patients treatedwith PSO was performed to determinewhether there were differences in radio-graphic follow-up parameters betweenthose that underwent APSF vs. PSF proce-dures. There were no significant differencesfound in terms of SVA correction (8.1 cm vs.7.1 cm; P � .8) or change in lumbar lordosis21.9° vs. 23.6°; P � .77). Of the 32 patients

ents for the Posterior-Only and Combined

ThoracolumbarCobb Angle

Sagittal Balance(Sagittal Vertical Axis) C

30.4 (18.8) 6.3 (7.8)

40.0 (15.6) 7.1 (5.7)

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ot treated with a PSO, 11 were treatedith multiple Smith-Petersen osteotomies

SPO) at levels throughout the lumbarpine. At last follow-up, these patients didot demonstrate a statistically significant

ncrease in lumbar lordosis (14.7° vs. 9.1°;� .49) or change in SVA (2.6 cm vs. 2.0

cm; P � .76) when compared with thosepatients not treated with any osteotomy.

Seventeen complications were reportedin 16 patients, including four pseudarthro-ses (Table 5). Other complications includedfour neurological injuries (three nerve rootinjuries and one cauda equina injury). Therewere four postoperative infections (all pos-terior wounds), one dural tear, and onedeep venous thrombosis. Three of the 15PSF patients (20%) had at least one compli-cation, and 13 of 30 (43%) APSF patientshad at least one complication. Althoughthere were more total complications in theAPSF group, there was no statistically sig-nificant difference in complication rates(P � .189). All cases of pseudarthrosis werereported in the APSF group (13%; P � .54).SRS-22 scores at last follow-up were similarbetween those with complications andthose without (3.31 vs. 3.81, respectively;P � .08). Those with a complication andthose without did not have significantly dif-ferent numbers of spinal levels operated (14

rior/Posterior Groups

l Balance Thoracic KyphosisLumbar

Lordosis

9 (5.1) 29.3 (24.8) �33.9 (16.3)

6 (3.3) 35.7 (21.9) �26.6 (25.4)

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20.6 (20.6) �30.5 (25.3)

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vs. 12.5, P � .08) or significantly differenthanges in SVA (1.2 cm vs. 4.6 cm, P � .08).

ISCUSSION

evision spinal surgery after a previous long fu-ion to the distal lumbar spine often requiresxtensionofthefusiontothesacro-pelvis.Threerevious studies have reported on this specificatient population (7, 9, 12). Kostuik et al. re-orted on the results of previously surgically

reated idiopathic scoliosis patients (12). Treat-ent methods included varying instrumenta-

ion and techniques. In the latter half of the timeeriod, the investigators reported lower pseud-rthrosis rates and improved outcomes withPSF procedures by combining the advantagesf anterior interbody support with posterior

umbo-sacral instrumentation The investiga-ors, however, reported a 17% vascular injuryate and multiple ureteral injuries associatedith the anterior approach.Islametal. laterreportedtheresultsof41pre-

iously fused adolescent idiopathic scoliosis pa-ientstreatedwithextensionofapreviousfusiono the sacro-pelvis (9). The majority of the pa-

Table 3. Postoperative Radiographic MeaCombined Anterior/Posterior Groups

SVACorrection* (cm)

SVA aFollow-u

APSF (n � 30) 4.7 (5.7) 2.3 (

PSF (n � 15) 2.1 (6.7) 4.2 (

P values 0.21 0.1

Data presented as mean (standard deviation).SVA, sagittal vertical axis; SRS, Scoliosis Research Society

fusion.*Sagittal vertical axis correction and change in lumbar l

follow-up values.

Table 4. Postoperative Radiographic MeaPedicle Subtraction Osteotomy Was Inclu

SVACorrection* (cm)

PostoSV

PSO (n � 13) 7.7 (6.6) 1.

No PSO (n � 32) 2.2 (5.3) 3.

P values 0.048

Data presented as mean (standard deviation).SVA, sagittal vertical axis; SRS, Scoliosis Research Socie*Sagittal vertical axis correction and change in lumbar lor

values.

180 www.SCIENCEDIRECT.com

ients were treated with APSF approaches. Vary-ng techniques for sacro-pelvic fusion weresed, with seven receiving iliac fixation. The usef osteotomies was not reported or discussed.hirty of 41 patients (73%) had a minimum ofne complication, including a 37% pseudar-

hrosis rate (15 of 41 patients). Patients with iliacxation demonstrated a lower rate of pseudar-

hrosis (53% vs. 21%).Recently, Crawford et al. evaluated exten-

ions to the sacrum of prior long fusions fordiopathic scoliosis, with the purpose of com-aring outcomes of patients whose extensionas performed using iliac crest or bone mor-hogenicprotein(7).Althoughitwasnotedthat

he patients treated without bone morphogenicrotein were more likely to have undergone a

horacoabdominal approach, a comparison ofPSF with PSF-only approaches was not specif-

cally performed.The previous studies demonstrate the chal-

enging nature of revising long fusions to theacro-pelvis. Although earlier studies have re-orted the results of predominantly APSF, pos-

erior-only approaches are being increasinglysed. Posterior approaches have been shown to

ments for the Posterior-Only and

)Change* in Lumbar

Lordosis (°)SRS-22 at Last

Follow-up

15.2 (21.2) 3.64 (0.75)

12.8 (18.3) 3.67 (0.64)

0.70 0.9

anterior-posterior spinal fusion; PSF, posterior-only spinal

are the differences between the preoperative and last

ments Stratified Based on Whether ain the Surgical Procedure*

ive)

Change in LumbarLordosis* (°)

PostoperativeSRS-22

22.5 (13.6) 3.68 (0.77)

11.1 (21.5) 3.63 (0.71)

0.041 0.87

, pedicle subtraction osteotomy.re the differences between last follow-up and prerevision

m

WORLD NEUROSURGERY, http://d

e effective in long fusions for adult scoliosis,lthoughthequestionofwhetherposterior-onlypproaches for extension of fusion to the sacro-elvis are effective has not been specifically ad-ressed (8). The present study therefore sought

o examine whether the type of surgical ap-roachimpactedoutcomeforextensionsofpre-ious fusions to the pelvis. Our results do notemonstrate any significant differences in ra-iographic or clinical outcomes between those

reated with APSF vs. PSF. Postoperative SVAnd SRS-22 scores were similar between theroups, suggesting that equivalent surgical re-ults can be obtained with a PSF-only approach.dditionally, although not statistically signifi-ant, there were more complications and moreseudarthrosis in the APSF group comparedith the PSF group. However, the lower pseud-

rthrosis rate with a posterior approach may beuetothelownumbersinourstudy,particularly

n the PSF group (n � 15).This study also found that improvement in

VA was achieved only when a PSO was per-ormed, regardless of whether a PSF or APSFpproachwasperformed.TheimprovementsinVA and lumbar lordosis were consistent withreviously reported average corrections (2-4,6). Interestingly, patients in whom multiplePOs were performed did not demonstrate sig-ificant improvement in SVA at follow-up. Pre-iousreportshavesuggestedthatmultipleSPOsan improve balance, even achieving similar re-ults as a PSO (1, 4, 18). One possible explana-ion for this finding in our study is the relativelymall number of patients treated with SPOs andhat those patients with the worst SVA werereatedwithaPSO.Theseresultsdosuggestthathen correction of positive sagittal malalign-ent is a priority, a PSO should be considered.It is important to recognize the potential lim-

tationsofthisstudy.Thisisaretrospectiveanal-sis and may underreport some complications.pproach type was at the discretion of the sur-eon and not randomized or controlled. Theumber of patients evaluated did not enabletratificationofpatientstreatedwithaposterior-nly approach based on whether interbody sup-ort was used. A prospective analysis is war-anted to further assess the ideal method forchieving the best results in these challengingatients.

ONCLUSIONS

atients who undergo long-segment posteriorpinalfusionthatendsinthedistallumbarspine

sure

t Lastp (cm

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this study, patients who underwent either a PSFor an ASPF for extension to the sacro-pelvisachieved similar postoperative radiographic re-sultsandclinicaloutcomescores,ataminimumof 2-year follow-up. Patients in both groupsachievedstatisticallysignificantimprovementinSVA correction with the utilization of a PSOwithout an apparent increase in complications.The addition of an anterior approach for exten-sion to the pelvis must be carefully weighedagainst its approach-related risks because theoverall complication rate and pseudarthrosisrate may be greater with a combined anterior/posterior approach.

ACKNOWLEDGMENTS

The authors thank Barbara Funk for Eng-lish editing and Terry Orrick for manuscriptpreparation.

REFERENCES

1. Booth KC, Bridwell KH, Lenke LG, Baldus CR,Blanke KM: Complications and predictive factorsfor the successful treatment of flatback deformity(fixed sagittal imbalance). Spine (Phila Pa 1976) 24:1712-1720, 1999.

Table 5. Distribution of Complicationsby Approach Group*

Combined Anterior-Posterior SpinalFusion

Posterior-OnlySpinal Fusion

Pseudarthrosis � 4 Infection

Infection � 3 Cauda equina injuryafter fall

Dural tear Worsening backpain

Nerve root injury � 3

Painful instrumentation

Deep venous thrombosis

Worsening back pain

*A total of 17 complications were reported, with 16patients affected (15 patients had 1 complication and1 patient had 2 complications).

WORLD NEUROSURGERY 79 [1]: 177-181

of fixed sagittal imbalance. J Bone Joint Surg Am85-A:454-463, 2003.

3. Bridwell KH, Lewis SJ, Rinella A, Lenke, LG, BaldusC, Blanke K: Pedicle subtraction osteotomy for thetreatment of fixed sagittal imbalance. Surgical tech-nique. J Bone Joint Surg Am 86-A (suppl 1):44-50,2004.

4. Cho KJ, Bridwell KH, Lenke LG, Berra A, Baldus C:Comparison of Smith-Petersen vs. pedicle subtrac-tion osteotomy for the correction of fixed sagittalimbalance. Spine (Phila Pa 1976) 30:2030-2037[discussion 2038], 2005.

5. Cochran T, Irstam L, Nachemson A: Long-term an-atomic and functional changes in patients with ad-olescent idiopathic scoliosis treated by Harringtonrod fusion. Spine (Phila Pa 1976) 8:576-584, 1983.

6. Connolly PJ, Von Schroeder HP, Johnson GE, Kos-tuik JP: Adolescent idiopathic scoliosis. Long-termeffect of instrumentation extending to the lumbarspine. J Bone Joint Surg Am 77:1210-1216, 1995.

7. Crawford CH 3rd, Bridwell KH, Cho W, BuchowskiJM, O’Shaughnessy BA, Chang MS, Auerbach JD:Extension of prior idiopathic scoliosis fusions to thesacrum: a matched cohort analysis of sixty patientswith minimum two-year follow-up. Spine (Phila Pa1976) 35:1843-1848, 2010.

8. Good CR, Lenke LG, Bridwell KH, O’Leary PT,Pichelmann MA, Keeler KA, Baldus CR, Koester LA:Can posterior-only surgery provide similar radio-graphic and clinical results as combined anterior (tho-racotomy/thoracoabdominal)/posterior approachesfor adult scoliosis? Spine (Phila Pa 1976) 35:210-218,2010.

9. Islam NC, Wood KB, Transfeldt EE, Winter RB, De-nis F, Lonstein JE, Ogilvie JW: Extension of fusionsto the pelvis in idiopathic scoliosis. Spine (Phila Pa1976) 26:166-173, 2001.

0. Kasten MD, Rao LA, Priest B: Long-term results ofiliac wing fixation below extensive fusions in ambu-latory adult patients with spinal disorders. J SpinalDisord Tech 23:e37-42, 2010.

1. Kebaish KM: Sacropelvic fixation: techniques andcomplications. Spine (Phila Pa 1976) 35:2245-2251,2010.

2. Kostuik JP, Musha Y: Extension to the sacrum ofprevious adolescent scoliosis fusions in adult life.Clin Orthop Relat Res: 53-60, 1999.

3. Moshirfar A, Rand FF, Sponseller PD, Parazin SJ,Khanna AJ, Kebaish KM, Stinson JT, Riley LH 3rd:Pelvic fixation in spine surgery. Historical overview,indications, biomechanical relevance, and currenttechniques. J Bone Joint Surg Am 87(Suppl 2):89-106, 2005.

4. Paonessa KJ, Engler GL: Back pain and disability

, JANUARY 2013 ww

5. Pichelmann MA, Lenke LG, Bridwell KH, Good CR,O’Leary PT, Slides BA: Revision rates following pri-mary adult spinal deformity surgery: six hundredforty-three consecutive patients followed-up totwenty-two years postoperative. Spine (Phila Pa1976) 35:219-226, 2010.

6. Potter BK, Lenke LG, Kuklo TR: Prevention andmanagement of iatrogenic flatback deformity. JBone Joint Surg Am 86-A:1793-1808, 2004.

7. Tsuchiya K, Bridwell KH, Kuklo TR, Lenke LG, Bal-dus C: Minimum 5-year analysis of L5-S1 fusion us-ing sacropelvic fixation (bilateral S1 and iliacscrews) for spinal deformity. Spine (Phila Pa 1976)31:303-308, 2006.

8. Voos K, Boachie-Adjei O, Rawlins BA: Multiple ver-tebral osteotomies in the treatment of rigid adultspine deformities. Spine (Phila Pa 1976) 26:526-533, 2001.

onflict of interest statement: Study group supportrovided by Depuy Spine. Justin S. Smith is a consultantor Medtronic, Depuy, and Biomet; received honoraria foreaching from Medtronic, Depuy, Biomet, and Globus; andeceived research study group support from Depuy.ouglas Burton is a consultant for Depuy, received

oyalties from Depuy, and received research support fromepuy. Christopher Shaffrey is a consultant for and has aatent with Biomet, received royalties and has a patentith Medtronic, is a consultant for Depuy, and received

rant funding from the National Institutes of Health andhe Department of Defense. Oheneba Boachie receivedrants/research support from Depuy, K2M Inc., andsteotec; is a consultant for Depuy, K2M Inc., Osteotech,nd Trans1 Inc.; is on the speakers’ bureau for K2M Inc.nd Trans1 Inc.; and received other financial support fromepuy, K2M Inc., and Trans1 Inc. Shay Bess receivedrant/ research support from Depuy, is a consultant forepuy, is on the advisory board/panel for Allosource and

he speaker’s bureau for Depuy, and received othernancial or material support from Pioneer Spine. Behroozkbarnia is a stockholder of Nuvasive; a consultant foruvasive, K2M, and Depuy Spine; and received grants

rom Nuvasive, K2M, and Depuy Spine. Greg Mundis is aonsultant for Nuvasive and K2M; has received honorariumrom Nuvasive and K2M; and received grants from Depuypine (research support), Nuvasive, K2M, and OREF. Ericlineberg is a consultant for Synthes and Alphatec; haspeaking and/or teaching arrangements with Synthes,epuy, and Stryker; participates in trips/travel for Depuy,tryker, and Nuvasive; and received grants from AOSpinend fellowship support from OREF and Synthes. Munishupta received grant/research support from Depuy; is aonsultant for Depuy, Osteotech, and Lanx; and is on thedvisory board/panel of Depuy and the speaker’s bureau ofepuy, Osteotech, Trans1, and Synthes.

eceived 20 November 2011; accepted 13 June 2012

itation: World Neurosurg. (2013) 79, 1:177-181.ttp://dx.doi.org/10.1016/j.wneu.2012.06.016

ournal homepage: www.WORLDNEUROSURGERY.org

vailable online: www.sciencedirect.com

2. Bridwell KH, Lewis SJ, Lenke LG, Baldus C, BlankeK: Pedicle subtraction osteotomy for the treatment

after Harrington rod fusion to the lumbar spine forscoliosis. Spine (Phila Pa 1976) 17:S249-S253, 1992.

1878-8750/$ - see front matter © 2013 Elsevier Inc.All rights reserved.

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