Rev. bras. ortop. vol.52 número5

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SOCIEDADE BRASILEIRA DE ORTOPEDIA E TRAUMATOLOGIA

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Original

Article

Comparison

of

Puddu

osteotomy

with

or

without

autologous

bone

grafting:

a

prospective

clinical

trial

夽

Marcus

Ceregatti

Passarelli,

José

Roberto

Tonelli

Filho,

Felipe

Augusto

Mendes

Brizzi,

Gustavo

Constantino

de

Campos,

Alessandro

Rozim

Zorzi

∗

_,

_João

_Batista

_de

_Miranda

UniversidadeEstadualdeCampinas(Unicamp),DepartamentodeOrtopediaeTraumatologia,Campinas,SP,Brazil

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Articlehistory:

Received4August2016 Accepted7September2016 Availableonline14September2017

Keywords:

Knee Osteoarthritis Bonegraft Osteotomy

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Objectives: Totestthehypothesisthatautologousiliacbonegraftsdonotenhanceclinical results anddonotdecrease complicationrates inpatientsundergoingmedial opening-wedgehightibialosteotomy.

Methods:Fortypatientsallocatedinarandomized,two-armed,double-blindedclinicaltrial wereevaluatedbetween2007and2010.Onegroupreceivedbonegraft,andtheothergroup wasleftwithoutfillingtheosteotomydefect.TheprimaryoutcomewastheKneeSociety Score.Radiographicmeasurementofthefrontalanatomicalfemoral-tibialangleandthe progressionofosteoarthritisaccordingtothemodifiedAhlbackclassificationwereusedas secondaryoutcomes.

Results:There wasnodifferenceinKSS scalebetweenthegraftgroup(64.4±21.8) and thegraftlessgroup(61.6±17.3;p=0.309).Therewasnodifferenceofanglebetweenthe femur andtibia inthefrontalplanebetweenthegroups(graft=184±4.6degrees, graft-less=183.4±5.1degrees;p=1.0),indicatingthatthereisnolossofcorrectionduetothe lackofthegraft.Therewassignificantaggravationofosteoarthritisinagreaternumberof patientsinagraftgroup(p=0.005).

Conclusion: Autologousiliacbonegraftdoesnotimproveclinicaloutcomesinmediumand long-termfollow-upofmedialopening-wedgehightibialosteotomyfixedwithafirst gen-erationPudduplateintheconditionsofthisstudy.

夽

PaperdevelopedatUniversidadeEstadualdeCampinas(UNICAMP),DepartamentodeOrtopediaeTraumatologia(DOT),Campinas, SP,Brazil.

∗ _{Corresponding}_author_.

E-mail:[email protected](A.R.Zorzi). http://dx.doi.org/10.1016/j.rboe.2017.09.001

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Comparac¸ão

de

osteotomias

de

Puddu

com

ou

sem

enxerto

ósseo

autólogo:

estudo

clínico

prospectivo

Palavras-chave:

Joelho Osteoartrite Enxertoósseo Osteotomia

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Objetivos: Avaliarahipótesedequeoenxertoósseoautólogodacristailíacanãomelhora oresultadoclínicoenãodiminuiaincidênciadecomplicac¸õesempacientessubmetidosà osteotomiadePuddu.

Métodos: Foramavaliados40pacientesalocadosdeformaaleatóriaemdoisgruposemum estudoclínicoduplocegoentre2007e2010.Umgruporecebeuenxertoósseoeooutrogrupo foideixadosempreenchimentodaosteotomia.Odesfechoprimáriofoiaescalaclínicada

KneeSociety(KSS).Amedidaradiográficadoânguloanatômicoentreofêmureatíbiano planofrontaleaprogressãodaosteoartritedeacordocomaclassificac¸ãomodificadade Ahlbackforamusadascomodesfechossecundários.

Resultados:NãohouvediferençadaescalaKSSnogrupocomenxerto(64,4±21,8)enogrupo semenxerto(61,6±17,3;p=0,309).Nãohouvediferençadoânguloentreofêmureatíbia noplanofrontalentreosgrupos(comenxerto=184±4,6graus;semenxerto=183,4±5,1 graus;p=1,0),indicaquenãoháumaperdadecorreçãopelafaltadoenxerto.Houvepioria daosteoartriteemumnúmeromaiordepacientesnogrupocomenxerto(p=0,005).

Conclusão: Oenxertoósseoautólogodacristailíacanãomelhorouoresultadoclínicoenão diminuiuaincidênciadecomplicaçõesempacientessubmetidosàosteotomiadePuddu, fixadascomplaca-calçodeprimeirageração,nascondiçõesdesteestudo.

Introduction

Theproximaltibialosteotomywithmedialopeningwedge, alsoknown asPuddu osteotomy,isaclassicalsurgical pro-cedureforthe treatment ofknee osteoarthritis,which has beenovershadowedbythedevelopmentofarthroplasty,but thathasresurgedduetotheincreasingnumberofcasesof osteoarthritisinyoungpatientsandnewsurgeries,suchas meniscaltransplantationandcartilagefillings,whichrequire adequatemechanicalalignmentofthelowerlimb.1_Compared totheotherosteotomytechniques,themedialopeningofthe tibiahave asadvantagesthe less morbidaccessroute, the possibilityofeasy intraoperativeadjustmentofwedgesize, preservationofbonestock,correctionclosertotheapexof thedeformity,andeaseofassociationwithotherprocedures inasinglesurgicaltime,suchasreconstructionoftheanterior cruciateligament.1,2

Themaincriticismofthetechniqueofmedialopeningis thecreation ofacleftinthe metaphysealcancellous bone, which can progresswith complicationsof bone consolida-tionandthelossofcorrectionduetocleftcollapse.Theuse ofautologousbonegraftingoftheiliaccresthasbeen advo-cated sincethe beginning of this surgeryto prevent these complications.3,4_Due_to_it_being_a_painful_procedure, associ-atedwithseveralcomplications,bonesubstituteshavebeen developedtofillthecleft.However,autologousbonegrafting, duetoitsosteogenesis,osteoinductionandosteoconduction properties,remainsthegoldstandard.5

Theempiricalexperiencesuggeststhat,inopeningsofup to10mm,itispossibletoleavethecleftunfilled.Toconfirm thisobservation,thisteammadeashort-termevaluationof

theresultsofosteotomieswithandwithouttheadditionofa bonegraft,whichshowednodifferenceinthetimeof consol-idationaftersixmonthsoffollow-up.6_Now,_the_objective_of thispaperisthelateevaluation,afteraminimumfollow-up offouryears,oftheclinicalandradiographicresultsobtained withorwithouttheadditionofthegraft.

Method

Subjects

Thestudysampleconsistedof46patientsundergoingPuddu osteotomy between 2007 and 2010, who were referred to surgicaltreatmentinauniversityhospitalafterfailureof non-surgicaltreatment.

Inclusioncriteria:

• Individualosteoarthritisofthemedialkneecompartment associatedwithvarusdeformity;

• Failureofnonsurgicaltreatment;

• Doublevarussecondarytochronicinstabilityofligament structuresoftheposterolateralcorner;

• AbilitytoreadandunderstandtheFreeInformedConsent Form (FIC), and agreement withthe participationin the research.

Exclusioncriteria:

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Recruitment

Elegible (n = 48)

Allocated (n = 46)

Allocation

Follow-up

Analysis

Excluded (n = 2)

♦ Lack of inclusion criteria

(n = 1)

♦ Refused to participate (n = 0)

♦Other reasons (n = 1)

“With graft” (n = 23)

♦ Received a graft (n = 23)

♦ Did not receive a graft (n = 0)

“non-graft” (n = 23)

♦ Did not receive a graft (n = 23)

♦ Received a graft (n = 0)

Analyzed (n = 21)

♦ Excluded (n = 0)

Analyzed (n = 19)

♦ Excluded (n = 0) Lost to follow-up (n = 2)

Change of address and telephone number

Lost to follow-up (n = 4)

Change of address and telephone number

Fig.1–Studyconsortflowchart.

• Plannedcorrectionswithwedgeslargerthan12.5mm; • Previoussurgeriesintheaffectedknee;

• Previousinfectionsintheaffectedlimb;

• Paininthelateraloranteriorcompartmentsoftheaffected knee;

• Lateralmeniscusinjury;

• Severekneeosteoarthritis(grades4and5ofAhlback clas-sification).

ThestudywasapprovedbytheResearchEthicsCommittee (CEP679/2006)andregisteredintheplatformClinicalTrials.gov (NCT00786942).

Allocation

Forty-sixpatientswererandomlydivided,withtheuseofa software(www.random.org),intwogroupsof23individuals. Allofthemunderwentthesamesurgicalprocedure,except forthe placementornotofabonegraft.Afteraminimum follow-upoffouryears,40patientswereevaluated(Fig.1).

Masking

Theallocationwaskeptsecretwiththeuseofasealed enve-lope,openedonlyafteranestheticinductionbyanursethat wasnotinvolvedwiththestudy.Inaddition,inordertoensure

confidentialitybetweenpatientsandevaluators(double-blind study)ailiaccrestgraft washarvestedfrom allpatients.In the“withoutgraft”group,thebonewassealedundersterile conditionsandstoredinafreezer,withtheapprovalofCEP.

Intervention

Thevalgusosteotomyoftheproximaltibia,withmedial open-ing wedge, known inour setting asPuddu osteotomy, isa classicalandwell-establishedtechnique.2,3,7_In_this_study,_we used first-generation wedge-plate fixation.8,9 _As _previously stated,twogroupswererandomlycreated.Tokeepmasking, andtoavoidtheclinicalaggravationbiasduetoiliaccrestpain, thegraftwasharvestedinbothgroups.Theinterventionof thisstudywastheplacementofthegraft.Thecontrolgroup wasleftwithoutit.

Surgicaltechnique

All caseswere operatedbythesamesurgeon. Thedetailed descriptionofthetechniquehasalreadybeenmadeina pre-viouspublication.10

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compartment(arthroscopictoilet).Atthattime,anursethat wasnotinvolvedintheresearchteamopenedtheenvelope withtheindicationofthepatient’sallocation.Inthecasesof the“no-graft”group,thebonewasvacuumpackedintriple polyamidepackagingandfrozeninaresearchlaboratory.At theendoftheprocedure,asuction drainwasplacedinall cases.

Postoperativeperiod

Thedrainwasalwaysremovedonthefirstdayaftersurgery. No type of immobilization was used and the limb active movement was stimulated on the first day after surgery. Therefore,nopharmacologicalprophylaxisforvenous throm-boembolismwasused. Tostandardizeloading,wechoseto leaveallpatientswithzeroloaduntiltheeighthweek(pair ofcrutches); gradual weight-bearing was started after this period.Allpatientshadthesamephysicaltherapyprotocol atthesamemedicalfacilitywheretheywereoperated.

After hospital discharge, the subjects were evaluated weeklyinanoutpatientclinic,bytworesearchersblindedto the allocation. Theradiographic evaluation wasperformed everyfifteendaysuntilconsolidation,whichwasdefinedby Solomonand Apleycriteria.11 _Following_bone_healing, _they wereevaluatedeverysixmonthsforthefirsttwoyears,and thenannually.

Outcomes

Thisstudy’smainoutcome wasthe clinicaland functional result ofthe Puddu osteotomy after atleast four years of follow-up,measuredbyKSS(KneeSocietyScore)scale.12 _This scaleisdividedintwoparts:anobjectiveone,whichcanvary fromzerotoonehundred;andafunctionalone,thatcanvary fromzerotoonehundred.

Otheroutcomesusedwere:

• Correction obtained in the frontal plane, measured in frontal knee X-ray, with monopodal weight-bearing, throughthe angle formedbythe anatomical axisofthe femurandtibia13,14_;

• Radiographic progression of knee osteoarthritis through modifiedAhlbackmethod15_;

• Conversionofarthroplastyorosteotomyreview.

Statistics

Tocalculatethesamplesize,weconsideredasignificant clin-icaldifferencebetweenthe means ofthe twogroupsof20 points,with80%powerandsignificancewithalphalessthan 5%.

Datawerepresentedasmeanandstandarddeviation(SD) forcontinuousvariables,orasabsolutefrequencyfor categor-icalvariables.Allpvaluesreportedaretwo-tailed.Thelevel ofsignificancewassetat0.05.TheKolmogorov–Smirnovtest was appliedtodetermine if the datafollowed normal dis-tribution.The comparisonamongthecontinuous variables was made with Student’s t-test for independent samples, whentheparametricassumptionscouldbeobtained;inother cases,Mann–Whitneytestwasused.Amongthecategorical

Table1–Demographicdataoftheresearchsubjects.

Withgraft n=21

Withoutgraft n=19

p

Age(years) 49.7±9.5 49.1±9.2 0.801

BMI 29.0±4.9 28.2±6.6 0.204

Follow-up(months) 74.3±14.4 70.6±11.8 0.688 Wedgeplate(mm) 10.3±2.5 9.8±2.0 0.607

Ligamentlesion 12 10 0.328

Smokers 5 11 0.028a

BMI,bodymassindex.

a _Significant.

Table2–Resultofclinicalevaluationthroughobjective andfunctionalKSscales.

Withgraft n=21

Withoutgraft n=19

p

PreobjectiveKS 48.9±11.2 49.5±11.6 0.830 PostobjectiveKS 64.4±21.8 61.6±17.3 0.309 PrefunctionalKS 57.1±16.5 59±24.47 0.376 PostfunctionalKS 74.8±20.8 76.8±29.4 0.374

KS,Kneescore.

variables, Pearson’s chi-square test or Fisher’s test were applied.

All analyseswere performedwiththesoftwareIBMSPSS

Statistics,(version22.0Armonk,NY,IBMCorp.).

Results

Forty-sixpatientsweredividedintotwogroupsof23,atthe beginningofthestudy,forsurgery;40werenowavailablefor

this late assessment;21 from the bonegraft group and 19

from the non-graft group. Sixpatients were notfound.No

patientwasconvertedintototalkneearthroplastyatthistime.

Demographicdatadidnotshowdifferencesbetweengroups

regardingthemajorityofpossiblevariables,suchasage,body massindex(BMI),wedgesizeofthewedgeplateusedtomake thecorrection,presenceofassociatedligamentlesions.There

was agreater number ofsmokersinthe “non-graft”group

(Table1).

The primary outcome,objective KSscale, didnot show any difference betweenthe groups (Table2).KS functional scale did not show any differences between the groups either.

Limbalignmentinthefrontalplanewasmeasuredbythe femorotibial(FT)angle,insupportingX-rays.Theresultsare illustratedinFig.2.Therewasnodifferenceintheincidenceof correctionlossinthenon-graftgroup,asshownbythevalues obtainedinthefinalsegment(p=1.0).

Table3showstheradiographicevolutionofosteoarthritis, accordingtothemodifiedAhlbackclassification.Thegroup “with graft” showed significant aggravation after surgery (p=0.005).

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+ 7,5º + − 3,0

+_5,4º+ −_4,1

− 0,9º + − 4,0 neutral

Preop.

Without graft With graft

6m recent

− 4,5º + − 4,9

+ 4º + − 4,6

+ 3,4º + − 4,1

Fig.2–Progressionoftheangleformedbytheanatomical axesoffemurandtibiainradiographswithfrontalplane support.

Table3–Radiographicprogressionofosteoarthritis accordingtothemodifiedAhlbackclassification.

Grade Withgraft n=21

Withoutgraft n=19

p

PreAhlback

1 1 3

2 7 6

3 13 10 0.504

PostAhlback

1 1 0

2 0 5

3 9 13

4 9 1

5 2 0 0.005a

a _Significant.

Discussion

Theresultofthisstudyshowedthattheadditionofautologous bonegraftoftheiliaccrestdidnotimprovethelateclinical outcomeofPudduosteotomiesanddidnotincreasetherisk ofcomplications,suchaslossofcorrectionandradiographic deteriorationofosteoarthritisofthekneewhencorrectionsof upto12.5mmareperformed.Inapreviouspaper,6_this_team hadalreadydemonstratedthelackofbenefitsinaddingthis typeofgraftforthehealingoftheosteotomy,buttherewas doubtaboutthepossibilityofcomplicationsorpooroutcome inalong-termfollow-up.

This finding is consistent with biological reasoning, becausethemetaphysealbone,contrarytocommonnotion, doesnotneedfullcontactifthereisrigidstability.16 _This_is achievedbymaintainingtheintegrityofthelateraltibial cor-tex,whichfunctionsasafulcrum,fromwhichformationof endostealcallustakesplace,whichprogressestothemedial sideoftheosteotomy.6,9,17

A recent systematic review with a meta-analysis that included25studiescorroboratesthisfinding.18_However,_the authorswarnaboutthefactthatonlyoneofthesestudies6_has agrade1levelofevidence.Alltheother24arecaseseriesor

non-controlledcomparativestudies.Therefore,thereisaneed formoregoodqualityclinicalstudiestoclarifythesubject.

RegardingtheKSSscale,theposthocanalysisof statisti-calpowershowedthatthesamplesizeissufficienttodetect differencesof20pointsamongthemeans.Thereissome con-troversyoverthe valueoftheMinimalClinicallyImportant Difference(MCID)forthisscale.Althoughsomesmall differ-encessuchas5.9forobjectiveKS,and6.4forfunctionalKS havealreadybeencalculated,19_another_study_indicates_that theMCIDforKS-FSshouldbe34.5.20_We_subjectively_adopted MCID as 20 in this study because we considered that the justificationforapainfulprocedure,suchastheremovalof autologousgraftfromtheiliaccrest,wouldrequireagreater effect(effectsize).InthissamplewefindalowCohen coeffi-cient(d=0.14).Thus,wethoughtthatalargersamplemight havesomescientificvaluebutnoclinicalapplicability.

Regarding the loss ofcorrection,we observedthat both groupshadprogressivelossofthecorrectionobtainedwith six monthsofsurgery inthis follow-up ofmorethan four yearsofduration,butthelosswasequalinbothgroups.As theevaluationswerealldoneonmonopodalweight-bearing radiographs,wedidnottakethemeasurementsonthe radio-graphsmadeimmediatelyafterthesurgery,whichhadtobe donewithoutweight-bearing,duetothepainandinabilityof thepatientstobeartheirweightatthatstage.Thus,itisnot possibletosayiftherewasalossintheperiodbetweensurgery andconsolidation.Thecorrectionangleinthefrontalplane, inthelong-termfinalevaluationofourstudy,issimilartothat reportedbyotherauthorsandiswithintherecommended tar-get(threetosixdegreesofvalgusbetweentheanatomicalaxes ofthefemurandthetibia).21

Regardingosteoarthritis,itisdifficulttofindabiological explanationforthemoremarkedprogressioninthe“graft” group.BecausethemodifiedAhlbackclassificationconsiders thesizeoftheposteriortibialosteophyteintheprofile radio-graphy,itcanbearguedthatthegraftmaysomehowstimulate osteophytegrowth,buttherearenodataintheliteratureto provethistheory.Anotherpossibleexplanationisthatsome hidden uncontrolled variable in this study hascaused this phenomenon.

Themainlimitationsofthis studyweretheinclusionof patientswithchronicligamentlesionsassociatedwithknee varusdeformity,alongwithpatientswithprimary osteoarthri-tis withastableknee, whichmay interferewiththeresult ofclinicalscales andsamplesize,whichwascalculatedfor theoutcomeofosteotomyconsolidation.However,sincethe requirementsfortheindicationofPudduosteotomyaremany, itisdifficulttoobtainasufficientsampleiftheinclusion crite-riainthestudyarefurtherrestricted.

Thisstudysupportstheideathat, inPudduosteotomies with anopeningof less than orequal to12.5mm, neither autologousbonegraftnorcostlybonesubstitutesoughttobe used.

Conclusion

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osteotomy,fixedwithfirst-generationwedgeplates,in correc-tionsofupto12.5mm.Therefore,intheseconditions,weavoid itsusebecauseitisaprocedurethatincreasesthepatient’s painandmorbidity.

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

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