Rev. bras. ortop. vol.50 número5

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

Original

Article

Evaluation

of

intraoperative

radioscopy

on

the

coronal

alignment

of

the

tibial

component

in

primary

knee

arthroplasty

夽

Hugo

Cobra,

Marcio

Bruno

Hadid,

Daniel

Torres

Jácome,

Eduardo

Branco

de

Sousa,

Alan

de

Paula

Mozella,

Rodrigo

Pires

e

Albuquerque

KneeSurgeryCenter,InstitutoNacionaldeTraumatologiaeOrtopedia(INTO),RiodeJaneiro,RJ,Brazil

a

r

t

i

c

l

e

i

n

f

o

Articlehistory: Received15July2014 Accepted23September2014 Availableonline20August2015

Keywords: Arthroplasty Radiology Knee

a

b

s

t

r

a

c

t

Objectives: Thepresentstudyhadtheobjectiveofevaluatingtheeffectoftheuseof intraop-erativeradioscopyincasesofprimarykneearthroplasty,onthefinalalignmentofthetibial component.

Methods:Patientswhounderwenttotalkneearthroplasty(TKA)betweenApril13,2013,and April20,2013,wereincludedinthestudy.Thesepatientswereevaluatedretrospectivelyand twogroupswereidentified:oneinwhichintraoperativeradioscopywasusedtoassessthe positioningofthetibialcomponentduringthesurgeryandtheotherinwhichthisresource wasnotused.

Results:Themeanangleofalignmentofthetibialcomponentinrelationtothetibial dia-physiswasgreaterinthegroupwithoutuseofintraoperativeradioscopy(90.82)thaninthe groupwithradioscopy(90.63),whichwasastatisticallysignificantresult(p<0.05). Conclusion: Useof intraoperativeradioscopy during TKAproduceda bettermean angle ofalignmentbetweenthetibialcomponentandthetibialdiaphysis,incomparisonwith nonuse.

©2014SociedadeBrasileiradeOrtopediaeTraumatologia.PublishedbyElsevierEditora Ltda.Allrightsreserved.

Avaliac¸ão

da

radioscopia

intraoperatória

no

alinhamento

coronal

do

componente

tibial

em

artroplastias

primárias

de

joelho

Palavras-chave: Artroplastia Radiologia Joelho

r

e

s

u

m

o

Objetivos:Avaliaroefeitodousodaradioscopiaintraoperatóriaemartroplastiasprimárias dejoelhosobreoalinhamentofinaldocomponentetibial.

Métodos:Foramincluídosnoestudoospacientessubmetidosàartroplastiatotaldojoelho (ATJ)entre13/04/2013e20/04/2013.Ospacientesforamavaliadosretrospectivamenteedois

夽

WorkperformedattheInstitutoNacionaldeTraumatologiaeOrtopedia(INTO),RiodeJaneiro,RJ,Brazil. ∗ _{Correspondingauthor.}

E-mail:[email protected](R.P.eAlbuquerque).

http://dx.doi.org/10.1016/j.rboe.2015.08.004

gruposforamidentificados,umcomusoderadioscopiaintraoperatóriaparaavaliac¸ãodo posicionamentodocomponentetibialduranteacirurgiaeosegundosemusodesserecurso. Resultados: Amédiadoângulodealinhamentodocomponentetibialemrelac¸ãoàdiáfiseda tíbiafoisuperiornogruposemusoderadioscopiaintraoperatória(90,82)emcomparac¸ão comogrupocomradioscopia(90,63),comresultadoestatisticamentesignificativo(p<0,05). Conclusão: OusoderadioscopianointraoperatóriodeATJproduzmelhormédiadeângulo dealinhamentoentreocomponentetibialemrelac¸ãoàdiáfisedatíbiaquandocomparado aonãouso.

©2014SociedadeBrasileiradeOrtopediaeTraumatologia.PublicadoporElsevier EditoraLtda.Todososdireitosreservados.

Introduction

Thetotalnumberofkneearthroplastyproceduresperformed everyyearhasincreasedexponentiallyandthemeanageof thepatientsundergoingthisinterventionhasdecreased,such thatthetopicoflongevityorsurvivalofimplantshasgained greaterattention.1,2

Thesuccessofthisprocedureisrelatedtoachievingproper alignment and correct management of ligament balance, alongwithprecisepositioningofitscomponents.3–5

Manyauthorshaveinvestigatedtheoutcomesfromtotal kneearthroplasty(TKA)andtheyhavereportedthatvarusor valgusmisalignmentsgreaterthan3◦_{resultingreaterchances}

of aseptic loosening and failure of the implant.5,6 _Berend etal.7 _{investigatedthemechanismsthroughwhichthe} tib-ialcomponentfailedandconcludedthatmisalignmentofthis componentgreaterthan3◦_{wouldincreasethefailurerate.}

Duringsurgicalprocedures,themethodsthatphysicians have available to them for verifying satisfactory position-ingofthecomponentsincludeclassicalalignmentguidance systems, evaluationmethodsusingnavigatedsurgery, con-ventionalradiographsandintraoperativeradioscopy.2,3,8

Aftertheoperation,the alignmentofprosthetic compo-nentscanbeevaluatedbymeansofsimpleradiographs,as recommendedbythe KneeSociety.1,9 _{On panoramic} radio-graphsinAPview,thetibialcomponentshouldbeat90◦ _in

relationtothelongaxisofthetibia1_(Fig.1).

Thepresentstudyhadtheobjectiveofevaluatingtheeffect ofusingintraoperativeradioscopyonthefinalalignmentof thetibialcomponent,incasesofprimarykneearthroplasty.

Materials

and

methods

We retrospectively evaluated 115 patients who underwent totalkneearthroplastybetweenApril13and20,2013:53in agroupwithoutuse ofintraoperativeradioscopy and62 in agroupwithuseofradioscopy.Allthepatientshad indica-tionsforundergoingtotalkneearthroplasty,withadiagnosis ofprimaryosteoarthrosis.Theexclusioncriteriawere previ-oussurgery,bodymassindex>35,extra-articulardeformity, varusand valgusdeformity>10◦_{, flexion>10}◦_,bonedefects

greaterthan5mmandrheumaticdiseases.Allofthepatients constitutedahomogenousgroupwithoutseriousdeformities andwithmoderatekneeosteoarthrosis.

Fig.1– Postoperativeradiographicalignment.

The primary arthroplasty was performed in accordance withtheclassicaltechniquesthathavebeendescribed,with the onlydifferencethat intraoperativeradioscopy mightor might notbeused, accordingto thepreferenceofthe sur-geonofthegroup.Inthegroupinwhichitwasdecidedtouse radioscopywithaPhilips®_{imageintensifier,asingleAPview}

ofthekneewasproducedontheoperatedkneejustafterthe tibialcutshadbeenmadeandthetestcomponenthadbeen emplaced.Thismadeitpossibleforthesurgeontointerfere inthefinalresultfrompositioningthetibialcomponent,such thattheviewedpositioncouldbeacceptedorcouldbealtered throughmakingabonecut.

After analysis on the sample, patients with incomplete medical documentation or absence of complete pre and postoperative routine radiological examinations would be excluded.However,noneofthepatientsinoursamplewere excluded.

Table1–Meansoftheabsolutevalues.

Withradioscopy Withoutradioscopy

Mean 90.63 90.82

Source:Hospitalservicefiles.

thelongaxisoftheleg.Theseareproducedinastandardized mannerbytheradiologyservice.Thepanoramicradiographs ofthelong axis oftheleg were producedin APprojection withthekneeextended,andthiswasdoneforallthepatients aftertheoperation.Thetube-filmdistancewastwometers. Carewas taken to place the lower limb ina neutral posi-tion, suchthat the patella would be directed anteriorly. A ShimatzoX-ray machine was used, with atechnique con-sistingof50kVand40mA.Theradiographswereevaluated regardingthecoronalalignmentofthetibialcomponent,on APpanoramicradiographsthatincludedthelongaxisofthe leg.Theanglebetweenalineparalleltothesurfaceofthe tib-ialcomponentandalinealongthelongaxisofthetibiawas calculated.Thiscalculationwasdoneusingtheangle mea-surementtoolsbelongingtotheMdicomViewerversion3.0 (27)digitalradiologicalviewingsoftware(MicrodataSystem). Inaddition,objectiveanalysiswasperformedonthemedical filesofthepatientsallocatedtoeachgroupanditwasverified fromthepostoperativeprotocolcardwhetherradioscopyhad beenusedornot.Ifithadbeenused,therewasachangeto thesurgicalstrategyregardingthetibialcut,withtheaimof ensuringbetterfinalalignmentofthetibialcomponent.The radiological analysisand viewingofthe medicalfiles were doneblindlybyasinglephysicianwhoisatitularmember oftheBrazilianSocietyofOrthopedicsandTraumatology,and whodidnotparticipateinthesurgicalprocedures.

Thedataweresubjectedtostatisticalanalysis,inorderto investigatetherelationship betweenthecoronalalignment anglesofthetibialcomponentofthegroupswithand with-out use ofintraoperativeradioscopy.Analysis bymeans of Student’s t test was used to ascertain whether there was anysignificantdifferencebetweenthegroups.Forthis,p val-ues<0.05weretakentobesignificant.

Results

Theresultsfrom thetwogroupsinquestionwere analyzed retrospectively.Thegroupforwhichintraoperativeradioscopy wasusedwascomposedof53patientsandthegroupwithout thiscomprised62patients.

Themeanalignmentangleofthetibialcomponentin rela-tiontothediaphysisofthetibiawas90.82±1.34inthegroup withoutuseofintraoperativeradioscopyand90.63±0.64in thegroupwithuseofradioscopy(Table1).Therangeinthe groupwithoutuseofradioscopywasfrom88.52to94.25and inthegroupwithuseofradioscopy,89.00–93.12(Table2).

Fromtheresultsofthettest,itcanbestatedthattherewas evidencefromthesamplethatindicatedthatthemean dis-placementswouldbedifferentbetweenthegroups(p=0.0069). In the group without use of radioscopy, five patients obtained alignment angles for the tibial component in

Table2–Valuesoftheanglesinthegroupswithand withoutradioscopy.

Withoutradioscopy Withradioscopy

92.18 90.30 93.32 90.90 94.10 89.90 91.00 91.16 93.50 89.82 90.10 90.30 90.80 91.50 89.70 90.30 90.10 90.60 89.30 89.90 92.80 90.07 89.70 90.31 90.10 89.90 89.90 93.12 89.80 90.32 90.30 90.46 92.23 89.95 90.10 89.80 90.60 90.42 90.00 90.26 90.00 90.80 90.50 89.30 90.30 89.80 91.10 92.70 89.00 90.13 91.00 89.83 90.03 90.15 90.10 90.30 91.60 89.92 89.00 90.10 90.10 89.90 90.72 90.10 89.00 89.87 89.80 90.16 91.10 90.30 91.60 89.76 90.10 90.31 90.30 90.16 91.00 90.06 91.50 89.97 90.90 90.31 90.27 90.32 90.83 89.76 93.32 90.41 92.70 89.87 90.56 90.07 90.17 90.03 90.10 90.30 90.20 89.16 88.52 90.62 92.27 89.93 94.75 90.03 91.54 90.52 90.24 90.93 90.87 90.30 89.00 89.90 90.50 90.30 90.10

relationtothediaphysisofthetibiathatweregreaterthan 93◦_{.Inthegroupwithuseofradioscopy,onepatientobtained}

ananglegreaterthan93◦_.

Discussion

Studiesintheliteratureareunequivocalregardingthe impor-tanceofproperalignmentoftheprosthetic componentsof total knee arthroplasty for the final result relating to the functionaloutcome.Likewise,thecomplicationsinherentto pooralignment,especiallywithregardtomechanicalfailure, havebeenwelldocumented.4_{Thus,therelevanceofassessing} intraoperativemethodsforguidingtheprecisionofthe align-menthasbeenincreasing.Nonetheless,thestudiessofarhave beeninconclusiveregardingwhatwouldconstitutethegold standard.Forthisreason,ourstudyevaluatedthefinal align-ment subsequentto totalknee arthroplasty, inaccordance withtheusualroutineofourkneesurgeons,andcompared groupswithorwithoutuseofintraoperativeradioscopy.

Theclassicalmethod,andtheonemostusedinmedical practice, is the mechanical method, making use of align-ment rodsdesignedfrom test components that havebeen implanted.Ourthinkingisthattheanatomicalparametersare important,butthatthehumaneyeisflawedandmaygiverise todeviationsofmorethan3◦_.

AuthorssuchasMullajietal.4_{andHourlieretal.}10 _have indicatedradioscopyasaneffectiveoptionalmethodfor guid-ingtheintraoperativealignment,withfavorableresults.Our studyshowedthatarthroplastyproceduresthatwerechecked usingintraoperativeradioscopytendedtoobtainbetterfinal coronalalignmentofthetibialcomponent,evenifthe differ-encewasonlysmall,incomparisonwiththeclassicalmethods thatdonothavethisverification.Hence,wecorroboratethe affirmationscitedaboveandconfirmthatgoodpositioningof theimplantinassociationwithdurabilityisimportant.Onthe otherhand,onenegativefactorinthismethodistheradiation towhichpatientsareexposedthroughuseofradioscopy.Our thinkingisthatwhentherisksarecomparedwiththebenefits, thereisanadvantageinusingradioscopy.

Anotherfactorofrelevanceinfavoring thistechniqueis theobservedlargenumberofbonecutsfortibialcorrection(30 cuts,i.e.48.4%ofthisgroup)thatwasperformedsubsequently tofluoroscopy.Theseweremadeviablethroughthis immedi-ateassessmentofthefinalresult,providedthroughtheadvent ofradioscopy,withtheaimofimprovingthepositioningofthe tibialcomponent.

Thedifferenceinthemeansofthealignmentangleofthe tibialcomponent,inrelationtothediaphysisofthetibiain thetwogroups,wasstatisticallysignificant(p=0.0069). More-over,thegroupwithradioscopyshowedameananglecloser totheneutralaxis(90◦_{)thanthatofthegroupwithoutuse}

ofradioscopy(90.63versus90.82,respectively,whichdepicts thegreatertendencyofthisfirstgrouptocorrectlyattainthe targetaxis.

Theliteratureshowsthatvarusorvalgusmisalignments greaterthan3◦_{resultingreaterchancesofasepticloosening}

andimplantfailure.5,6_{Itwasobservedinthisstudythatinthe} groupwithuseofradioscopy,onlyonepatientpresentedvarus greaterthan3◦_{,whileinthegroupwithoutuseofradioscopy,}

fivepatientspresentedvarusgreaterthan3◦_{.Thisshowsthat}

therewasatendencytowardgreaterchanceofmisalignment inthegroupwithoutuseofradioscopy.

Navigated surgeryfortotalknee arthroplasty isanother technique in which the aim is to achieve a well-aligned implant,therebyleadingtogreaterdurabilityofthis prosthe-sis.Thenavigatedsurgerytechniquehasbeenpresentedasan importantoptionforaddressingthedeficiencyofprecisionof traditionalguides,butitaddstothedurationoftheoperation andtothefinalcost.2,11–14_{Forthisreason,weadvocatetheuse} ofradioscopyintotalkneearthroplastyprocedures.Thiscan beusedinmosthospitalsinBrazil,giventhatsoftwareand sensorsare unnecessary.Thenavigationtechniqueusedin totalkneearthroplastyproceduresmaysometimeshavetobe abortedduetoproblemswiththesensorsorwithanatomical referencepointsthataremarkederroneously.

The strong points of this study that we can highlight includethelargesamplethatwasachievedoverashortperiod oftime,providedthroughakneereferralcenterandthe cen-ter’sexperiencedgroupofkneesurgeonswiththecapacityto useauniformtechniquethatdivergedonlyinafewoperative stages, particularlywithregardtouseofradioscopy,which wasthefocusofourstudy.Moreover,ourpatientsconstituted ahomogenous groupwithoutserious deformitiesandwith moderatekneeosteoarthrosis.Anotherpositivepointwasthe blindingofasingleevaluatorofthefinalanglesobtained.

Thefactsthatthesurgicalprocedureswerenotperformed byasinglesurgeonandthatnopostoperativedescriptionsof thecutsmadeinthegroupwithoutradioscopywereincluded inthefilescanbetakentobeweaknessesofourstudy.

Conclusion

Use of intraoperative radioscopy during total knee arthro-plastyproducesabettermeanalignmentanglebetweenthe tibialcomponentandthediaphysisofthetibia,incomparison withnonuse.

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

r

e

f

e

r

e

n

c

e

s

1.WindsorRE,ScuderiGR,MoranMC,InsallJN.Mechanismsof

failureofthefemoralandtibialcomponentsintotalknee

arthroplasty.ClinOrthopRelatRes.1989;248:15–9.

2.WengYJ,HsuRW,HsuWH.Comparisonofcomputer-assisted

navigationandconventionalinstrumentationforbilateral

totalkneearthroplasty.JArthroplast.2009;24(5):668–73.

3.HuangTW,HsuWH,PengKT,HsuRW,WengYJ,ShenWJ.

Totalkneearthroplastywithuseofcomputer-assisted

navigationcomparedwithconventionalguidingsystemsin

thesamepatient:radiographicresultsinAsianpatients.J

BoneJointSurgAm.2011;93(13):1197–202.

4.MullajiA,KannaR,MarawarS,KohliA,SharmaA.

Comparisonoflimbandcomponentalignmentusing

computer-assistednavigationversusimageintensifier-guided

randomized,single-surgeonstudyof467knees.JArthroplast. 2007;22(7):953–9.

5. KimSJ,MacDonaldM,HernandezJ,WixsonRL.Computer

assistednavigationintotalkneearthroplasty:improved

coronalalignment.JArthroplast.2005;207Suppl.3:123–31.

6. JeffcoteB,ShakespeareD.Varus/valgusalignmentofthetibial

componentintotalkneearthroplasty.Knee.2003;10(3):243–7.

7. BerendME,RitterMA,MedingJB,FarisPM,KeatingEM,

RedelmanR,etal.Tibial-componentfailuremechanismsin

totalkneearthroplasty.ClinOrthopRelatRes.2004;

428:26–34.

8. BolognesiM,HofmannA.Computernavigationversus

standardinstrumentationforTKA:asingle-surgeon

experience.ClinOrthopRelatRes.2005;440:162–9.

9. SatoT,KogaY,OmoriG.Three-dimensionallowerextremity

alignmentassessmentsystem:applicationtoevaluationof

componentpositionaftertotalkneearthroplasty.J

Arthroplast.2004;19(5):620–8.

10.HourlierH,FennemaP.Intraoperativefluoroscopyimproves

surgicalprecisioninconventionalTKA.KneeSurgSports

TraumatolArthrosc.2014;22(7):1619–25.

11.NovakEJ,SilversteinMD,BozicKJ.Thecost-effectivenessof

computer-assistednavigationintotalkneearthroplasty.J

BoneJointSurgAm.2007;89(11):2389–97.

12.AndersonKC,BuehlerKC,MarkelDC.Computerassisted

navigationintotalkneearthroplasty:comparisonwith

conventionalmethods.JArthroplast.2005;207Suppl.3:132–8.

13.EkET,DowseyMM,TseLF,RiaziA,LoveBR,StoneyJD,etal.

Comparisonoffunctionalandradiologicaloutcomesafter

computer-assistedversusconventionaltotalknee

arthroplasty:amatched-controlretrospectivestudy.JOrthop

Surg(HongKong).2008;16(2):192–6.

14.ChauhanSK,ScottRG,BreidahlW,BeaverRJ.

Computer-assistedkneearthroplastyversusaconventional

jig-basedtechnique.Arandomised,prospectivetrial.JBone