Rev. bras. ortop. vol.52 número2

SOCIEDADE BRASILEIRA DE ORTOPEDIA E TRAUMATOLOGIA

w w w . r b o . o r g . b r

Original

article

Posterior

three-column

osteotomies

for

the

treatment

of

rigid

thoracic

kyphosis

–

a

case

series

夽

Marcelo

Simoni

Simões,

Ernani

Vianna

de

Abreu,

Bruno

Costamilan

Winkler

HospitalErnestoDornelles,PortoAlegre,RS,Brazil

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Articlehistory:

Received16December2015 Accepted31May2016

Availableonline24January2017

Keywords:

Osteotomy Kyphosis Spinalcurvatures Spinaldiseases

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Objective:Toevaluatetheresultsandcomplicationsofaseriesofpatientswhounderwent three-columnosteotomyusingtheposteriorapproachforcorrectionofcomplexcasesof rigiddorsalkyphoticdeformity.

Methods:Reviewofclinicalrecordsandimagesof15consecutivecasesofpedicle subtrac-tionosteotomies,bone-disk-boneosteotomies,orvertebralcolumnresection,recordingthe etiology,typeandlevelofosteotomy,extensionoffixation,complications,andpre-and post-surgicalmeasurementsofthesagittalcurvesandpelvicparameters.

Results:Sixpediclesubtractionosteotomieswereperformed,oneofwhichintwoadjacent vertebrae,aswellastwobone-disk-boneosteotomiesandsevenvertebralcolumnresection, twoofwhichwereperformedintwoadjacentvertebrae.Themeancorrectionwas39.3◦_for

theangularkyphosisand33.9◦_{fordorsalkyphosis.Thecorrectionsweresimilarregardless}

ofthekindofosteotomy,theoperatedspinalsegment,ortheapproachinoneortwolevels, butthismaybeasampleeffect.

Eightcomplicationswereobservedinsixpatients(40%ofcases):twomedical complica-tions,fiveearlyandonelatesurgicalcomplication(over90daysaftersurgery).Therewere threereoperationswithinlessthanoneyearfromtheinitialsurgeryandonecaseof per-sistentparaparesis.Clinicalcomplicationswereresolvedwithoutsequelae.Therewasno significantlossofcorrectionduringthesegment,exceptintwocasesofmajormechanical failureduetoajunctionalsegmentfracture.

Conclusion: Despitebeingcomplexandaggressiveprocedures,pronetovarious complica-tions,osteotomieswithresectionofthethreecolumnsarehighlyeffectiveinthecorrection ofrigidkyphoticdeformitiesandsafeenoughtojustifyitsuseinselectedcases.

©2017PublishedbyElsevierEditoraLtda.onbehalfofSociedadeBrasileiradeOrtopedia eTraumatologia.ThisisanopenaccessarticleundertheCCBY-NC-NDlicense(http:// creativecommons.org/licenses/by-nc-nd/4.0/).

夽

StudyconductedatHospitalErnestoDornelles,PortoAlegre,RS,Brazil.

∗ _{Correspondingauthor.}

E-mail:[email protected](B.C.Winkler).

http://dx.doi.org/10.1016/j.rboe.2017.01.004

190

Osteotomias

posteriores

de

três

colunas

para

tratamento

de

cifose

dorsal

rígida

–

Série

de

casos

Palavras-chave:

Osteotomia Cifose

Curvaturasdacolunavertebral Doenc¸asdacolunavertebral

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Objetivo: Avaliarosresultadoseascomplicac¸õesdeumasériedepacientessubmetidosa osteotomiasdastrêscolunasporabordagemposteriorparacorrec¸ãodecasoscomplexos dedeformidadecifóticadorsalrígida.

Métodos: Revisãodosprontuáriosedasimagensde15casosconsecutivosdeosteotomias desubtrac¸ãopedicular,osteotomiasosso-disco-ossoouvertebrectomiasposteriorestotais, comregistrodasetiologias,tipoeníveldeosteotomia,extensãodafixac¸ão,complicac¸õese medidaspré-epós-cirúrgicasdascurvassagitaisedosparâmetrospélvicos.

Resultados: Foramfeitasseisosteotomiasdesubtrac¸ãopedicular,umaemduasvértebras adjacenteseduasosso-disco-ossoesetevertebrectomiasposteriorestotais,duasemduas vértebrasadjacentes.Asmédiasdecorrec¸ãoforamde39,3◦_{paraacifoseangulare33,9}◦

paraacifosedorsaltotal.Ascorrec¸õesforamsemelhantes,independentementedotipode osteotomiausado,dosegmentoespinhaloperadooudaabordagememumoudoisníveis, masissopodeserefeitodaamostra.

Ocorreramoitocomplicac¸õesemseispacientes(40%doscasos),duasclínicas,cinco cirúgi-casprecoceseumacirúrgicatardia(maisde90diasapósacirurgia).Houvetrêsreoperac¸ões commenosdeumanodacirurgiainicialeumcasodeparaparesiamantida.Ascomplicac¸ões clínicasforamresolvidassemsequelasmaiores.Nãohouveperdadecorrec¸ãosignificativa duranteosegmento,excetoemdoiscasosdefalhamecânicamaiorporfraturadesegmento juncional.

Conclusão:Emborasejamprocedimentoscomplexos,agressivosesujeitosacomplicac¸ões,as osteotomiascomressecc¸ãodastrêscolunassãoaltamenteeficazesnacorrec¸ãodas deformi-dadescifóticasrígidasesegurasobastanteparajustificarseuusoemcasosselecionados.

©2017PublicadoporElsevierEditoraLtda.emnomedeSociedadeBrasileirade OrtopediaeTraumatologia.Este ´eumartigoOpenAccesssobumalicenc¸aCCBY-NC-ND (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Introduction

Thedevelopmentofspinalsurgeryhasledsurgeonstoface increasinglycomplexcases,aimingnotonlyatspinal decom-pressionandstabilization,butalsoatdeformitiescorrection andthespinebiomechanicalbalancerestoration.1

Inthelastdecade,subtractionosteotomieshavebecome popularinthemanagementofspinaldeformities2,3_andhave beguntobeusedinawiderangeofsituations.Thefocuses ofthisstudyarepedicularsubtractionosteotomy(PSO), bone-disk-boneosteotomy(BDB),andvertebral columnresection (VCR),allofwhichareposterior,middle,andanteriorresection techniquesthroughasingleposterioraccessthatcanbeused invery rigiddeformities,withthree-column arthrodesisor ankylosis,providingsignificantangularcorrectionsinasingle levelwithoutelongationoftheanteriorcolumnofthespine (Fig.1).

Material

and

methods

Thiswasaretrospectivestudyof15casesofpatientswithrigid dorsalkyphoticorkyphoscolioticdeformitiesofseveral etiolo-gies,surgicallytreated,whosepostoperativefollow-upranged from6to60months(meanof36months).Datafromcharts and measurements of spine curves were collected by the

four-lineCobb method. Lumbar lordosisand dorsal kypho-sis were measured betweenthe points of inversionof the curve,regardlessofthelevel(Fig.2).Incaseswheremorethan onesurgerywasperformed,resultsconsideredmeasurements takenafterthelastapproach.

Surgicaltechnique

Fig.1–Typesofthree-columnosteotomy.(A)Pedicularsubtractionosteotomy(PSO);resectionofavertebralbodywedge.

(B)Bone-disk-boneosteotomies(BDB);resectionofawedgewiththeapexonthedisk.(C)Vertebralcolumnresection(VCR);

resectionoftheentirevertebralbodywiththedisksaboveandbelow.

Results

Sampledata

Five men and ten women, agedbetween 13 and 66 years (mean:38,SD=±18.8),wereoperated.Therewerefourcases ofpost-traumatickyphosis(26.6%),fourcasesof kyphoscolio-sisduetohemivertebrae(26.6%),twocasesofPott’sdisease (13.3%), twocases ofjunctionalkyphosis (13.3%), one case of deformity after pathological fracture due to multiple

myeloma,onecaseofkyphoscoliosisdueto neurofibromato-sis,andonecaseofrigidScheuermann’skyphosisinanadult patient. Onlythe twopatientswithjunctionalkyphosis, in whomalongfixationofthelumbosacralspinewasobserved, presentedsignificantsagittalimbalance.Forallothercases, eveninthepresenceofsignificantkyphosis,overallsagittal balancewasmaintainedattheexpenseofcompensatory lum-barhyperlordosisandpelvicanteversion.

Nineofthe15casespresentedverysignificantspinalcord compression, but there were onlytwo cases of neurologi-cal compressive deficits (case 1, Pott’s disease and case 8,

Fig.2–Methodoftakingmeasurementsofangularkyphosis(AK),sacralslope(SS),pelvicincidence(PI),dorsalkyphosis

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post-neoplastic).Incase5,paraplegia wascausedbyacute trauma,notbylatedeformity.

Thefollowingprocedureswereperformed:sixPSOs(40%), oneofwhichoccurredintwoadjacentvertebrae(case6);two BDBs (13.3%); and seven VCRs (46.7%), two of which were conducted in two adjacent vertebrae (cases 1 and 2). One osteotomywasperformedintheproximalthoracicsegment (T2–T4),seven(46.7%)inthemiddlethoracicsegment(T5–T9), andseven(46.7%)inthelowerthoracicsegment(T10–T12).

DataaresummarizedinTable1.

Surgicalresults

Themeanangularkyphosiscorrectionwas39.3◦_(SD=±14.6◦₎

andtotalkyphosis33.9◦ _(SD=±17.7◦_{).Consideringthe}

oper-ated segment, angular kyphosis correction and full dorsal kyphosiswere,respectively,33◦_and22◦_{inupperdorsallesions}

(T2–T4),41.1◦_(SD=

±13◦_)and35◦_(SD=

±21.3◦_{)inmedialdorsal}

lesions(T5–T9),and38.3◦_(SD=±17.7◦_)and34.4◦_(SD=±15.9◦₎

in lower dorsal lesions (T10–T12). Considering the type of osteotomyused,thecorrectionofangularkyphosisachieved byBDBwas28◦₍₂₆◦_and30◦_);byPSO,41.5◦_(29–53◦_,SD=

±9.4◦_);

andbyPTV,42◦ _(10–63◦_,SD=

±19.5◦_{).Completeneurological}

recoverywasobservedinthetwocasesthatpresented para-paresisduetodeformity.

Complications

Eight complications occurred in six patients, as shown in

Table2.Theclinicalcomplicationswereapulmonary throm-boembolism and a thyroid storm in ayoung woman with hypothyroidismwhodiscontinuedthemedicationonherown. Bothcaseswereresolvedwithoutmajorsequelae.

In the case of neurofibromatosis, there was a partial medullarylesionduringvertebrectomy,whichwasperformed viathetransduralaccess,sincethemeningocelesembraced theentirecontourofthevertebra.Patientpresentedleft dor-salparesisinthepostoperativeperiod,compatiblewithgait, andwithprogressiveimprovement.However,sevenmonths aftersurgery,patientreturnedwithseverespastic parapare-sis.Investigationshowedsignificantspinalcordcompression byanarachnoidcystabovetheoperatedarea,probablydueto arachnoidadhesionsafterthetransduralapproach. Further surgerywasperformed,butpatientremainedparapareticand spastic(case9,Fig.3).Therewerethreeearlymechanical com-plications,oneinstrumentationfailure(case8,Fig.4),andtwo junctionalfracturesatthemostcaudalinstrumentedlevel, withasmalllossofcorrectioninoneandimportantlossin another,whichledtothedecompensationofthesagittal bal-ance(case11,Fig.5).Asignificantlossofcorrectionwasnot observedinanyoftheothercasesduringfollow-up.

Discussion

Three-columnosteotomiesare aggressivesurgeries,usually indicatedinsituationsinwhichothertechniqueswithlower potentialmorbidityarenotapplicable,eitherduetolackof flexibilityofthespineorthepresenceofseverefocalangular deformity.2_{Itsprimaryadvantageistoallowthecorrectionof}

rigiddeformitieswithouttheneedforanteriorrelease.PSOis thebestknowntechnique;somepublicationshavedescribed againof30to40degreesoflordosisperleveladdressed.4–6 Inthedorsalspine,itsusehasbeenmuchmorelimitedand thepotentialforcorrectionisnotsoclear.7_{In1994,Lehmer} etal.8_{reportedfourcasesoperatedinthelowerdorsalspine,} with amean correction of29.5 degrees. Bridwell2 _reported gainsofapproximately25degrees.WiththeuseoftheVCR inthe dorsalspine,Rajasekaranet al.9 _{reportedameanof} 36degreesofcorrectionincasesoftuberculosis,while Shi-modeetal.5_{reportedameancorrectionof56degreesinsevere} kyphoscoliosis. In the present series, the corrections were ofapproximately 40 degrees,with nosignificant difference betweentechniques.

Thoracicosteotomiesdiffergreatlyfromthoseofthe lum-bar.First,toallowaneffectiveclosureoftheosteotomy,the ribsthatarticulatewiththesuperiorandinferiordisksmustbe released;second,becausethesurgeryisdoneatlevelswhere thereisbonemarrow,thereisalimittothebone mobiliza-tionthatcanbeachievedwithacceptablerisk.O’Shaughnessy et al.7 _{reportedthat20–25mmofposteriorlaminar closure} canbetoleratedwithoutneurologicalproblems,butthisvalue hasnotbeenvalidatedexperimentally.Tomitahasshownthat spinalcordshorteningassociatedwiththeremovalofa ver-tebralbody isnotaproblem, andneitheristhe ligationof segmental vessels in up tothree levels.10,11 _{Gertzbein and} Harris12_{postulatedthatdistortionofthecordandclamping} oftheduralsacarepotentialrisksassociatedwithspinalcord shortening; theseauthors recommend avoidingcorrections ofmorethan40◦_{.Inthepresent series,resectionsofupto}

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Case G-A Etiology PS Deficitpre AKpre PI SVApre DKpre LLpre SSpre LOP LFIX TOS AKpost SVApost DKpost LLpost SSpost CorK

1 M-28 PostTBC 0 Paraparesis 60 60 4 52 48 36 T8+T9 T5–T12 VPC 21 2 33 40 31 39

2 M-48 PostTBC 0 105 59 6 82 46 40 T5+T6 T2–T10 VPC 42 4 44 40 38 63

3 F-54 PTD+Infection 5 33 55 6.5 51 47 30 T12 T8–L3 VPC 4 5.5 43 50 30 29

4 M-16 Congenital 0 78 66 −3 73 90 49 T11 T7–L2 VPC 20 2 43 70 45 58

5a _{F-27 PostPTD 0 Paraplegia 33 50 0 68 40 0 T11-T12 T9–L3 BDB 3} −3 42 52 15 30

6 F-62 PostPTD 0 54 42 4.5 75 58 33 T8+T9 T5–T12 PSO 15 1 62 62 35 39

7 M-13 Congenital 0 63 42 3 90 90 40 T11 T8–L2 VPC 28 1 33 38 23 35

8 F-63 PostNeo 0 Paraparesis 70 60 5 72 50 30 T3 C2–T7 PSO 37 0 50 66 40 33

9 F-20 Dysplastic 0 90 50 1 126 78 38 T11 T8-L4 VPC 30 0 70 70 42 60

10 F-22 Congenital 0 42 68 −4.5 70 90 45 T7-T8 T2–L1 BDB 16 −2 44 70 50 26

11 F-66 Junctional 2 45 54 8.5 75 49 27 T9 T2–L3 PSO 16 6 44 49 30 31

12 F-37 Scheuermann 0 60 53 1.5 73 78 35 T11 T4–L3 PSO 14 0 40 60 35 46

13 M-17 CEH 0 30 64 −1 73 90 45 T10 T8–L3 VPC 20 0.5 52 70 39 10

14 F-48 PostPTD 1 63 60 0 108 89 36 T8+T9 T2–L2 PSO 14 −6 34 60 42 74

15 F-50 Junctional 1 75 66 36 106 50 47 T7 T2–IL PSO 22 8 66 74 45 53

AKpre,preoperativeangularkyphosis(degrees);AKpost,postoperativeangularkyphosis(degrees);DKpre,totalpreoperativedorsalkyphosis(degrees);DKpost,postoperativedorsalkyphosis (degrees);CorAK,correctionofangularkyphosis(degrees);PS,numberofprevioussurgeries;SVApre,preoperativesagittalverticalaxis(centimeters);SVApost,postoperativesagittalverticalaxis (centimeters);IL,sacralandiliacfixation;PI,pelvicincidence;SSpre,preoperativesacralslope(degrees);SSpost,postoperativesacralslope(degrees);LLpre,preoperativelumbarlordosis(degrees); LLpost,post-operativelumbarlordosis(degrees);NEO,deformityafterboneneoplasia;LFIX,fixatedlevels;LOP,levelatwhichtheosteotomywasperformed;G-A,gender-age;TOS,osteotomytype; PTD,posttraumaticdeformity.

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Table2–Complications.

Case Earlyclinical Earlysurgical Surgicalprocedures Reoperations Sequelae

03 Deepinfection Surgicaldressing

06 T12fracture Lossofcorrection

08 Cervicalpullout Revisionofthefixation

09 Spinalcordinjury Arachnoidcyst Cystresection Spasticparaparesis

10 Thyroidcrisis

11 TEP L4fracture Lossofcorrection

cases.The recommended approachis tomaintaina mean arterialpressureofatleast75mHg,loosenthecorrectionand, if thepotentials donotrestore, then removethe rodsand undothecorrection,attemptingagainwithanotherstrategy aftersignalsarerestored.15_{Neurologicaldeficitinthepresent} serieswasnotrelatedtothecorrectionofthedeformity,but ratheroccurredduringboneresectionperformedvia transdu-ralaccessinthecaseofneurofibromatosis,whilethepatient was being monitored. Mechanical complications are more commonthanneurologicalones,sincekyphoticdeformities haveanaturaltendencytoprogressionandinstrumentation overloadisnotuncommon,especiallywhensagittalbalance isnot corrected. In some cases, the patient appearsto be used tothe anterior position ofthe trunkand the projec-tionofthehead,andassumesthistypeofpostureevenafter correctionofthedeformity,whichsuggeststheexistenceof someneurologicalorproprioceptivemechanism that influ-encestheindividualabilitytomaintainthebodybalance.6_The mostdescribedmechanical complicationsare pseudarthro-sis, failure of instrumentation, and loss ofcorrection over time.Intheliterature,theincidenceofpseudarthrosisranges from0to5%5,18,19 _{andinstrumentationfailuresoccurinup} to8%ofthe cases, generallyrelated toinsufficient correc-tion,osteoporosis,orlackofanteriorsupportinVCR.7,9,19_In thepresentseries,therewerenocasesofpseudarthrosis,and

onlyonepatientwasfollowed-upforlessthanayear.Three earlymechanicalcomplicationswere observed:onecasein whichscrewspulledout(case8,Fig.4)andtwofracturesof theinstrumentedlowervertebra,bothrelatedto osteoporo-sis.ThefirstcasewasafixationfromT5toT12,andfracture occurred due toinsufficiency in T12.As loss ofcorrection wassmallandclinicaloutcomewassatisfactory,theauthors decidednottoperformasecondsurgicalapproach.Afterthis case,thegroup’sconductwasmodifiedandthedefinitionof distalfixationlevelswasmadeincludingthefirstlevelin lor-dosis,asrecommendedinthetreatmentofScheuermann’s kyphosis.20_{Inthesecondcase,therewasanL4fracturewith} significantimpactonsagittalbalanceandfunctionaloutcome, butpatientwasnotreoperatedduetoclinical contraindica-tion(case11,Fig.5).Withtheexceptionofthesetwocasesof fracture,nosignificantlossofcorrectionwasobservedduring follow-up. Thismaintenanceofthe correctionovertimein uncomplicatedcaseswasobservedinmostseries.8,10,11,17,21 Astherearenoabsolutevaluesfordefiningnormal kypho-sis,theimportantparametersintheevaluationofcorrections arereducedangularkyphosisandtherestorationofsagittal balance.22_{Inthisseries,onlytwocasesofjunctionalkyphosis,} whichhadpreviousfixationsofT10tothesacrum,had sig-nificantsagittaldecompensation.Thisisduetotwofactors: first, the mostpowerful spinopelvic sagittal compensation

Fig.3–Kyphoscoliosisduetodysplasticneurofibromatosis,with90-degreerotationofT11onT12,withspinal

compression.Patientpresentedonlylowerlimbhyperreflexia,butwasbedriddenduetopain.(A)Panoramicradiograph.

(B)Magneticresonanceimagingandradiograph,focusedshowingtheangulardeformitywith90◦_{ofT10–T12kyphosisand}

spinalcompression.(C)Magneticresonanceimagingshowingtheextentofthemeningocelesaroundtheangulardeformity

thatledtothetransduralapproach.(D)Postoperativeradiographshowinggoodcorrectionofthedeformity.(E)Magnetic

resonanceimagingsevenmonthsaftertheinitialsurgeryshowinganarachnoidcystattheupperendofthe

instrumentation,twolevelsabovetheVCR,withimportantcompressionanddisplacementofthespinalcord.Thepatient

Fig.4–AngularkyphosisduetopathologicalfractureofT3aftermultiplemyelomatreatment.Parapareticpatientwith

strengthgradeIII.(A)Initialappearanceonmagneticresonanceimagingwith70◦_{ofT2–T4kyphosisandspinalcord}

compression.(B)Postoperativetomographyshowinggoodcorrectionofthedeformity.(C)Radiographandtomographymade

afterdischargeduetosuddenincreaseincervicalpain.Theexamsshowpullingofthescrewsinthelateralcervical

masses,withlittlelossofcorrection.(D)Finalaspectafteranewapproach,inwhichthedorsalscrewsweremaintainedand

thecervicalimplantsreplaced,withextensionofthefixationuptoC2.TheorthostaticradiographshowstheC7plumbline

exactlyontheposterioraspectofthesacralplateau(case8).

mechanism is the adjustment oflumbar lordosis,23,24 _and injuries that do not compromise the lumbar mobility are moreeasilybalanced;second,asamatteroftrigonometry,the higherthelevelofangularkyphosis,theloweritsimpacton

theoverallsagittalbalance,becauseitisfurtherawayfromthe base.25_{Inbothcases,animprovementonthesagittalvertical} axis(SVA)withoutcompletenormalizationwasobserved.In casesoflumbarosteotomiesforsagittalimbalancecorrection,

Fig.5–L3–S1arthrodesisforovertenyears,whichevolvedwithL2–L3stenosisandextensionofthefixationuptoT10for

threeyears,developingprogressivejunctionalkyphosis.(A)Radiographshowingtheconsolidationoftheoldarthrodesis.

(B)ExtensionofthefixationuptoT10,withdevelopmentofjunctionalkyphosis.(C)Postoperativeradiographshowing

fixationextensionuptoT2andT9PSO,withgoodkyphosiscorrection.Asthelumbarsegmentwasfirmlyconsolidatedand

therewere12anchoragepointsdistaltotheosteotomy,itwasdecidedtofixateonlyuptoL4.(D)Radiograph60daysafter

surgeryshowinglossoflumbarlordosisandsagittalimbalance.Thepatientprojectedhertrunkwhenrisingfromalow

chairandfeltacrackinherlowerback.(E)DetailoftheradiographshowingwedgingofL4andlumbarrectification.Asthe

patienthadpulmonarythromboembolismpostoperativelyandwasanticoagulated,inadditiontootherclinicalproblems,it

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Roseetal.26_{concludedthatthecombinationofPI+CD-LL≤45}◦

hasapredictivevalueof91%formaintainingsagittalbalance uptotwoyearsaftersurgery.Inthedorsalspine,this princi-pledoesnotappeartobevalid,sincethelossofbalancethat occursovertimeismainlyduetotheprogressionofdorsal kyphosis;itismorenoticeableincasesinwhichthesuperior instrumentedlevelisbelowT5.26_{Inthepresentseries,only} 50%ofpatientsmetthiscriterionandyettherewasnolossof correction.

Final

considerations

Although these procedures are complex, aggressive, and subject to complications, osteotomies with three-column resectionhaveproved tobequite effectiveand sufficiently safeforthecorrectionofrigidsagittaldeformities.Duetothe severityofthistypeofdeformity,theauthorsbelievethatthe useofosteotomiesinthetreatmentofthisconditionishighly justified.

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

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