Rev. bras. ortop. vol.49 número6

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

Original

Article

Importance

of

radiological

studies

by

means

of

computed

tomography

for

managing

fractures

of

the

tibial

plateau

夽

,

夽夽

Clécio

de

Lima

Lopes

a,∗

,

Carlos

Antônio

da

Rocha

Cândido

Filho

b

,

Thiago

Almeida

de

Lima

e

Silva

c

_,

_Marcelo

_Carvalho

_Krause

_Gonc¸alves

a

_,

Ricardo

Lyra

de

Oliveira

c

_,

_Paulo

_Rogério

_Gomes

_de

_Lima

c

a_Instituto_Romeu_Krause_of_Traumatology_and_Orthopedics,_Recife,_PE,_Brazil b_Knee_Treatment_Center,_Recife,_PE,_Brazil

c_Hospital_Otávio_de_Freitas,_Recife,_PE,_Brazil

a

r

t

i

c

l

e

i

n

f

o

Articlehistory:

Received30November2013 Accepted6January2014 Availableonline30October2014

Keywords:

Tibialfractures/classification Tibialfractures/radiography Computedtomography Operativesurgicalprocedures

a

b

s

t

r

a

c

t

Objectives: To evaluate the concordance among knee surgery specialists regarding the classification andsurgicaltechniqueindicated incasesoftibial plateaufracture, using conventionalradiographsandcomputedtomography.

Methods:Forty-fourpatientswithfracturesofthetibialplateaushownonradiographicand tomographicimageswereselected.Thesewereevaluatedbyspecialistsattwodifferent times,withanintervalofsevendays.Onthefirstoccasion,thespecialistsonlyhadaccess totheradiographs,whileonthesecondoccasiontheyhadaccesstobothradiographsand computedtomographyimages.Theirconcordancewasevaluatedbymeansofthekappa coefficient.

Results:TheinterobserverreliabilityoftheSchatzkerclassificationonthefirstoccasionwas 0.36andonthesecondoccasion,0.35.Thiswasconsideredtopresentlowreproducibility. Inevaluatingtheintra-observerreproducibilityofthisclassification,themeankappaindex was0.42,whichwasclassifiedasmoderate.Fromevaluatingthechoiceofsurgicalaccess, theinter-observerreliabilitywas0.55onthefirstoccasionand0.50onthesecond,whichwas consideredtopresentmoderatereproducibility.Evaluationontheimplantchosenshowed thattheinterobserverreliabilitywas0.01onthefirstoccasionand−0.06onthesecond, whichwasconsideredtobepooranddiscordant.Inevaluating theclassificationofthe threecolumns,theinter-observerreproducibilitywas0.47(p<0.0001),whichwasclassified asmoderateconcordance.

夽

Pleasecitethisarticleas:deLimaLopesC,daRochaCândidoFilhoCA,deLimaeSilvaTA,Gonc¸alvesMCK,deOliveiraRL,deLima PRG.Importânciadoestudoradiológicopormeiodetomografiacomputadorizadanomanejodasfraturasdoplatôtibial.RevBrasOrtop. 2014;49:593–601.

夽夽

WorkdevelopedattheOrthopedicsandTraumatologyService,HospitalOtáviodeFreitas,Recife,PE,Brazil. ∗ _{Corresponding}_author_.

E-mail:cleciolimopes@yahoo.com.br(C.deLimaLopes). http://dx.doi.org/10.1016/j.rboe.2014.10.010

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Palavras-chave:

Fraturasdatíbia/classificac¸ão Fraturasdatíbia/radiografia Tomografiacomputadorizada Procedimentoscirúrgicos operatórios

Avaliaraconcordânciaentreespecialistasemcirurgiadejoelhocomrelac¸ãoàclassificac¸ão eàtécnicacirúrgicaindicadanasfraturasdoplatôtibialcomousodasradiografias conven-cionaisedatomografiacomputadorizada.

Métodos: Foramselecionados44pacientescomfraturasdeplatôtibialcomsuasimagens radiográficasetomográficas,asquaisforamavaliadasporespecialistasemdois momen-tosdistintos,comintervalodesetedias.Noprimeiromomentoosespecialistastiveram acesso apenasàsradiografiasenosegundoàsradiografiaseàsimagensdetomografia computadorizada.Aconcordânciafoiavaliadapormeiodocoeficientekappa.

Resultados: AconfiabilidadeinterobservadorparaaclassificaçãodeSchatzkernoprimeiro momentofoi0,36enosegundo0,35,consideradasdebaixareprodutibilidade.Naavaliação dareprodutibilidadeintraobservadordessaclassificação,amédiadoíndice␬foide0,42, classificadacomomoderada.Aavaliaçãodaescolhadoacessocirúrgicoteveuma confiabil-idadeinterobservador de0,55numprimeiromomentoe0,50nosegundo,consideradas de reprodutibilidademoderada.Quando avaliadooimplanteescolhido,a confiabilidade interobservadorfoide0,01noprimeiromomentoe-0,06nosegundo,consideradasruim ediscordante.Naavaliaçãodaclassificaçãodastrêscolunas,areprodutibilidade interob-servadorfoide0,47(p<0,0001),classificadacomoconcordânciamoderada.

Conclusão: Ousodatomografiacomputadorizadanãoapresentoumelhoriana concordân-ciainterobservadornaclassificac¸ãodeSchatzker,bemcomonãopromoveumudanc¸ano planejamentopré-operatório.

Introduction

Fracturesofthetibialplateaupresentriskstoknee function-ing,sincethesearejointfracturesoftheproximalthirdofthe tibiawhereloadtransmissiontakesplace.Theyresultfrom axialcompressiveforcesthatmayormaynotbecombined withvarus orvalgusstress onthe knee joint.1 _These frac-turesaccountforaround1.3%ofallfracturesandaremore common amongmale patients. This typeof injurymainly affectsyoungormiddle-agedpatientswho aresubjectedto high-energytrauma,andelderlypeoplewhoareexposedto low-energytrauma.2_The_treatment_for_these_fractures_aims toachieveanatomicalreductionofthejointsurfaceand sta-bleosteosynthesis inordertoenableearlymobilization,so astopreventcomplicationssuchasjointstiffnessand post-traumaticarthrosis.3

Forthesefractures,preoperativeplanningisfundamental. The clinical history, trauma mechanism, age and associ-atedcomorbiditiesinfluencethetreatmentdecisions.Inthe physicalexamination,thesoft-tissueenvelope,neurovascular functioningandassociatedlesionsshouldbeassessedsothat theinterventionwillbeappropriate.4

Radiographicevaluationonthesefracturesinvolves four views: anteroposterior, lateral, internal oblique and exter-nal oblique (Fig. 1). Computed tomography (CT)is ofgreat valuefordeterminingthelocationandmagnitudeofthejoint depression.1

Managementofthesefracturesconsistsofusing compre-hensiveclassificationsystemsthatareeasilyreproducibleand haveprognosticvalue,therebymakingitconceptuallyeasier todefinetacticsandsurgicalaccesses.

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Fig.1–Radiographicviewsfordiagnosingtibialplateaufractures:(A)anteroposterior;(B)lateral;(C)internaloblique;(D) externaloblique.1

Schatzker

Type I Fracture with lateral shearing

Type II Shearing + lateral joint depression

Type III Pure joint depression

Type IV Fracture of the medial plateau

Type V Bicondylar fracture

Type VI Bicondylar fracture extending to metaphysis

Fig.2–Schatzker’sclassification.1

medialandlateral(Fig.1).Inadditiontousingtheaxialview, theaccuracyoftheclassificationwasobtainedwiththeaidof theAPviewwith3Dreconstruction.

According to this classification, an independent joint depressionwithacorticalfractureofthecolumnisdefined asafractureofthecorrespondingcolumn.Purejoint depres-sion(SchatzkerIII)isdefinedasazero-columnfracture.The majorityoffracturesduetosimpleslateralshearingor depres-sion/shearing(SchatzkerIandII)arefracturesofonecolumn (lateralcolumn).However,whenthereisananterolateral frac-ture and a separate posterolateral joint depression with a fractureoftheposteriorcorticalbone,itisdefinedasa frac-tureoftwocolumns(lateralandposteriorcolumns).Ajoint depression in the posterior column witha fracture of the posterior corticalbone isalsodefined asa fracture ofone

Medial column Lateral column

A

O

C

B D

Posterior column

Fig.3–Three-columnclassificationproposedbyLuoetal.5_: illustrationofdivisionofthetibialplateauintothree

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column (posterior column), which is not included in Schatzker’sclassification.Theothertypicaltwo-column frac-tureisanteromedialwithanisolatedposteromedialfragment (fractureoftheposteriorandmedialcolumns),which tradi-tionallywasinSchatzker’stypeIV(medialcondylarfracture). Three-columnfractures are defined ashaving atleast one independentjointfragmentineachcolumn.Thecommonest three-column fracture is the traditional bicondylar type (SchatzkertypesV andVI),combinedwithanisolated pos-terolateraljointfragment.

Theobjectiveofthepresentstudywastoassessthe impor-tanceofCTformanagingfracturesofthetibialplateauand compare the classification, surgical approach and type of implantused.

Materials

and

methods

Forty-four patients with tibial plateau fractures attended between April and August 2012 were selected in a non-probabilistic consecutive manner. They all came from the orthopedicsandtraumatologyserviceofastatetrauma refer-ralhospital.Theirradiologicalexaminations(CTandsimple radiographs) were analyzed by 10 orthopedists who were membersoftheBrazilianSocietyofOrthopedicsand Trauma-tologywithexperienceofkneesurgery.Thesespecialistswere blindedandworkedindependently.

Theequipmentusedtoconductthecomplementary exam-inationson thecaseswere theSiemens VMIcompactplus 500machineandtheVisionLineLX2processorforthe sim-pleradiographsandtheGE16-channelmultislicetomograph fortheCTscans.

Photographicimageswereobtainedusingacamerawitha resolutionof5.0megapixels(iPhone4smartphone),copied into digital media (.jpg format) and displayed for each observerseparatelybymeansofaPowerPointpresentationin Office2007,onatablet(iPad2)withhigh-resolutionimages (1024×768).

Allthespecialistshadaccesstothesameimages,without identificationofthepatients. Theseimageswereevaluated intwostages:time1andtime2,withaseven-dayinterval betweentheevaluations.Attime1,radiographicimagesof theaffectedkneeweredisplayedinanteroposterior,lateral, internaloblique andexternaloblique views.Thespecialists answeredaquestionnaireregardingtheSchatzker classifica-tionandthechoiceofaccessrouteandimplanttobeused (Table1).Attime2,inadditiontotheradiographs,CTscans wereshown.Thequestionnairewasappliedagain,withthe additionoftheclassificationofthecolumns.Attime2,the

Thedatagatheredwereprocessedinadatabasethatwas cre-atedusingtheSPSS19.0softwareforWindows,inwhichthe universalvariablesandthevariablesanalyzedwereincluded. Afterthisstage,thedatawereanalyzedusingthecoefficient. The coefficient evaluated the concordance between observersbymeansofpairedanalysis,inwhichtheproportion ofconcordancebetweentheobserverswascompared,taking intoaccountthepercentageconcordanceduetochance.The valuesrangedfrom −1(absolutediscordanceto+1(perfect concordance).5–7

This project was approved by our institution’s research ethics committee, inaccordance with Resolution 196/96of theNationalHealthCouncil(GuidelinesandRegulatoryRules forResearchInvolvingHumanBeings).Informationaboutthe studywasgiventoeachpatient,andeachpatientwasaskedto signfreeandinformedconsentstatement.Ifthepatientwas consideredtobeincapableofsigningtheform,acloserelative wasaskedtodoso.

Results

Duringthestudyperiod,44patientswereincluded:28males (64.0%)and16females(36.0%).Theirmeanagewas45.6±16.7 years,withaminimumof21andamaximumof77.However, sincetherewasgreatvariationofages,wenotedthatthemode wasinthefifthdecadeoflife.

At evaluation time 1, the interobserver reliability of Schatzker’sclassificationwas0.36,whichwasclassifiedaslow. Inevaluatingthechoiceofsurgicalaccess,theinterobserver reliability was0.55,which was moderatelyreproducible.In evaluatingthechoiceofimplantstobeused,theinterobserver reliabilitywas0.01,whichwasclassifiedaspoor(Table2).

Atevaluationtime2,theinterobserverreliabilityrelatingto Schatzker’sclassificationwas0.35,whichwasclassifiedaslow. Inevaluatingthesurgicalaccess,theinterobserverreliability was0.50,whichwasmoderatelyreproducible.Inevaluating thechoiceofimplants,theinterobserverreliabilitywas−0.06, whichwasclassifiedasdiscordant(Table3).

Therewasnostatisticallysignificantdifferenceinrelation tothemeansforinterobserverreproducibilityattimes1and2 oftheevaluationofSchatzker’sclassification(p=0.658)(Fig.4). Themeaninterobserverconcordanceattime1regarding the choiceofimplant was0.05(poor)and attime2,it was

−0.03 (discordant). There was no difference in the means regardingthechoiceofimplant,inrelationtotheevaluation times(p=0.055)(Fig.5).

Table4andFig.6showthedegreeofintraobserver

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Table2–Interobserverkappaindexattime1inrelationtoSchatzker’sclassification,accessrouteandimplant.

Schatzker Access Implant

kappa(p-value) kappa(p-value) kappa(p-value)

Observers 0.36(<0.0001)a _0.55_(<0.0001)a _0.01_(0.676)

Observer1vs.Observer2 0.47(0.004)a _0.64_(0.011)a ₋_0.08_(0.742) Observer1vs.Observer3 0.39(0.008)a _0.84_(<0.0001)a ₋_0.10_(0.679) Observer1vs.Observer4 0.75(<0.0001)a _0.68_(0.006)a ₋_0.01_(0.740) Observer1vs.Observer5 0.54(<0.0001)a _0.52_(0.015)a ₋_0.10_(0.511) Observer1vs.Observer6 0.19(0.029)a _0.69_(0.002)a _0.12_(0.434) Observer1vs.Observer7 0.16(0.123) 0.41(0.056) −0.13(0.300) Observer1vs.Observer8 0.11(0.378) 0.35(0.149) −0.02(0.914) Observer1vs.Observer9 0.36(0.031)a _0.64_(0.010)a ₋_0.19_(0.193) Observer1vs.Observer10 0.64(<0.0001)a _0.83_(0.002)a _0.24_(0.127) Observer2vs.Observer3 0.59(0.001)a _0.50_(0.033)a _0.50_(0.033)a Observer2vs.Observer4 0.36(0.027)a _0.64_(0.010)a _0.00_(1.000) Observer2vs.Observer5 0.50(0.003)a _0.44_(0.041)a ₋_0.16_(0.214) Observer2vs.Observer6 0.37(<0.0001)a _0.66_(0.003)a ₋_0.19_(0.125) Observer2vs.Observer7 0.27(0.005)a _0.28_(0.143) ₋_0.02_(0.898) Observer2vs.Observer8 0.31(0.0255)a _0.64_(0.010)a ₋_0.12_(0.338) Observer2vs.Observer9 0.73(<0.0001)a _0.54_(0.072) ₋_0.12_(0.338) Observer2vs.Observer10 0.60(<0.0001)a _0.79_(0.007)a _0.35_(0.019)a Observer3vs.Observer4 0.38(0.015)a _0.69_(0.004)a ₋_0.01_(0.740) Observer3vs.Observer5 0.50(0.003)a _0.55_(0.006)a _0.15_(0.251) Observer3vs.Observer6 0.26(0.004)a _0.70_(0.001)a _0.06_(0.658) Observer3vs.Observer7 0.32(0.012)a _0.37_(0.104) _0.09_(0.404) Observer3vs.Observer8 0.03(0.822) 0.37(0.124) −0.04(0.740) Observer3vs.Observer9 0.48(0.008)a _0.50_(0.033)a _0.11_(0.376) Observer3vs.Observer10 0.47(0.011)a _0.67_(0.009)a _0.23_(0.154) Observer4vs.Observer5 0.53(<0.0001)a _0.52_(0.015)a _0.07_(0.087) Observer4vs.Observer6 0.16(0.091) 0.69(0.002)a _0.06_(0.165) Observer4vs.Observer7 0.04(0.731) 0.55(0.009)a _0.12_(0.026)a Observer4vs.Observer8 0.21(0.128) 0.68(0.006)a _0.08_(0.026)a Observer4vs.Observer9 0.25(0.134) 0.64(0.010)a ₋_0.02_(0.621) Observer4vs.Observer10 0.40(0.011)a _0.83_(0.002)a _0.05_(0.428) Observer5vs.Observer6 0.54(<0.0001)a _0.84_(<0.0001)a _0.38_(0.201) Observer5vs.Observer7 0.35(0.003)a _0.35_(0.035)a _0.29_(0.091) Observer5vs.Observer8 0.29(0.056) 0.52(0.015)a _0.74_(0.011)a Observer5vs.Observer9 0.40(0.007)a _0.44_(0.041)a _0.23_(0.425) Observer5vs.Observer10 0.88(<0.0001)a _0.31_(0.145) ₋_0.13_(0.072) Observer6vs.Observer7 0.28(0.002)a _0.45_(0.017)a _0.19_(0.258) Observer6vs.Observer8 0.31(0.022)a _0.69_(0.002)a _0.12_(0.658) Observer6vs.Observer9 0.30(<0.0001)a _0.31_(0.154) _0.12_(0.658) Observer6vs.Observer10 0.46(<0.0001)a _0.51_(0.025)a ₋_0.10_(0.201) Observer7vs.Observer8 0.09(0.493) 0.55(0.009)a _0.21_(0.193) Observer7vs.Observer9 0.25(0.023)b _0.28_(0.143) _0.02_(0.914) Observer7vs.Observer10 0.45(<0.0001)a _0.39_(0.071) ₋_0.20_(0.125) Observer8vs.Observer9 0.21(0.081) 0.28(0.264) −0.22(0.461) Observer8vs.Observer10 0.17(0.247) 0.48(0.068) −0.05(0.425) Observer9vs.Observer10 0.49(0.003)a _0.79_(0.007)a ₋_0.17_(0.011)a

a _{Statistically}_significant.

In evaluating the three-column classification, the inter-observer reproducibility was 0.47 (p<0.0001), which was classifiedasmoderate(Table5andFig.7).

ThemeanSchatzkerconcordancewas0.36(low)andthe three-columnconcordancewas0.48(moderate).Themean concordancewasgreater inthethree-column classification thanintheSchatzkerclassificationattime2(p=0.003)(Fig.8).

Discussion

ControversyregardingroutineuseofCTscansandtheideal classificationmethodfortibialplateaufracturescontinuesin

the literature.Thisaroused ourinterest inconducting this study.

The Brazilian National Health System (SUS) provides healthcare fora largepercentage ofthis country’s popula-tion.High-complexityexaminationssuchasCTandmagnetic resonancearenotroutinelyavailableatsomeservices.Their highcost,alongwithaccessdifficulties,thusplacesvalueon conductingstudiesontheuseoftheseexaminations.

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Observer1vs.Observer9 0.49(<0.0001)a _0.49_(0.058) ₋_0.14_(0.462) Observer1vs.Observer10 0.22(0.192) 0.61(0.044)a ₋_0.21_(0.132) Observer2vs.Observer3 0.40(0.004)a _0.21_(0.477) ₋_0.24_(0.111) Observer2vs.Observer4 0.48(0.006)a _0.49_(0.058) ₋_0.01_(0.740) Observer2vs.Observer5 0.71(<0.0001)a _0.50_(0.049)a _0.00_(0.740) Observer2vs.Observer6 0.19(0.017)a _0.53_(0.019)a _0.02_(0.621) Observer2vs.Observer7 0.27(0.046)a _0.38_(0.201) _0.05_(0.251) Observer2vs.Observer8 0.43(<0.0001)a _0.49_(0.058) _0.00_(1.000) Observer2vs.Observer9 0.61(<0.0001)a _0.49_(0.058) ₋_0.18_(0.120) Observer2vs.Observer10 0.60(0.001)a _0.61_(0.044)a _0.58_(0.002)a Observer3vs.Observer4 0.42(0.003)a _0.49_(0.058) ₋_0.04_(0.338) Observer3vs.Observer5 0.52(<0.00001)a _0.50_(0.049)a ₋_0.08_(0.251) Observer3vs.Observer6 0.27(0.016)a _0.37_(0.099) ₋_0.01_(0.887) Observer3vs.Observer7 0.38(0.011)a _0.38_(0.201) ₋_0.03_(0.740) Observer3vs.Observer8 0.44(0.001)a _0.49_(0.058) _0.00_(1.000) Observer3vs.Observer9 0.66(<0.0001)a _0.49_(0.058) _0.43_(0.033)a Observer3vs.Observer10 0.52(<0.0001)a _0.21_(0.477) ₋_0.15_(0.266) Observer4vs.Observer5 0.49(0.005)a _0.67_(0.008)a _0.09_(0.064) Observer4vs.Observer6 0.26(0.022)a _0.55_(0.011)a ₋_0.12_(0.073) Observer4vs.Observer7 0.28(0.043)a _0.35_(0.125) ₋_0.13_(0.441) Observer4vs.Observer8 0.32(0.019)a _1.00_(<0.0001)a _0.00_(1.000) Observer4vs.Observer9 0.29(0.057) 1.00(<0.0001)a _0.13_(0.137) Observer4vs.Observer10 0.50(0.003)a _0.49_(0.058) ₋_0.06_(0.402) Observer5vs.Observer6 0.27(0.005)a _0.41_(0.074) ₋_0.14_(0.621) Observer5vs.Observer7 0.36(0.009)a _0.33_(0.156) ₋_0.08_(0.251) Observer5vs.Observer8 0.29(0.049)a _0.67_(0.008)a _0.00_(1.000) Observer5vs.Observer9 0.63(<0.0001)a _0.67_(0.008)a ₋_0.08_(0.165) Observer5vs.Observer10 0.59(0.002)a _0.67_(0.008)a _0.01_(0.740) Observer6vs.Observer7 0.39(<0.0001)a _0.20_(0.338) _0.13_(0.154) Observer6vs.Observer8 0.09(0.480)a _0.55_(0.011)a _0.00_(1.000) Observer6vs.Observer9 0.27(0.015)a _0.55_(0.011)a ₋_0.17_(0.038)a Observer6vs.Observer10 0.36(0.001)a _0.53_(0.019)a _0.02_(0.621) Observer7vs.Observer8 0.10(0.371) 0.35(0.125) 0.00(1.000) Observer7vs.Observer9 0.31(0.020)a _0.35_(0.125) ₋_0.24_(0.106) Observer7vs.Observer10 0.37(0.006)a ₋_0.04_(0.898) _0.15_(0.087) Observer8vs.Observer9 0.33(0.015)a _1.00_(<0.0001)a _0.00_(1.000) Observer8vs.Observer10 0.40(0.013)a _0.49_(0.058) _0.00_(1.000) Observer9vs.Observer10 0.28(0.077) 0.49(0.058) −0.18(0.183)

Intheresultsfromourstudy,Schatzker’sclassification pre-sentedalowrateofgeneralinterobserverreproducibility,both attime1,whenonlyradiographswereanalyzed,andattime2, whenradiographsandCTscanswereanalyzed.Inevaluating theintraobserverreproducibility,theresultfoundcomprised moderatemeanconcordance.

In a study involving 50 cases of tibial plateau fracture, Charalambous et al.9 _observed _that _{Schatzker’s} classifi-cation presented highly variable intra- and interobserver reproducibility. They concluded that these results should be taken into consideration, so that surgeons would use this classification for guiding treatments and determining prognoses.

Waltonetal.10_compared_the_Schatzker_and_AO_Group clas-sificationsandconcludedthattheAOwasmorereproducible. Theyalsoobservedthatthetwoclassificationswereoriginally basedonradiographicstudies.Thisfactormayhaveinterfered withtheresultsfromourstudy,giventhatwealsousedCT images.

AccordingtoBrunneretal.,11_{Schatzker’s}_{classification} pre-sented good intra- and interobserver reproducibility when performedwiththeaidofCT.

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1.0

0.5

0.0

–0.5

X-ray X-ray + tomography

Schatzker

Kappa concordance coefficient

Fig.4–Boxplotofinterobserverreproducibilityof Schatzker’sclassificationinrelationtothetwoevaluation times.

The studies in the literature on the concordance and reproducibilityofSchatzker’sclassificationstillpresentvery divergentresultsbut,asalsoobservedinourstudy,mostof themhavecharacterizedthisclassificationsystemashaving poortomoderatereproducibility.9,13–15

In some studies, CT has not changed the reproducibil-ity of Schatzker’s classification in relation to conventional radiographs,14 _as _also _shown _in _our _results. _In _other studies, this examination has become important for this evaluation.11,12

Martijn et al.13 _evaluated _the _impact _of _CT _on _inter and intraobserver concordance, in comparison with plain radiographs,foroperativeplanningandforSchatzker’s classi-ficationoftibialplateaufractures.Theyconcludedthatusing CT in addition to plain radiographs did not improve the

p-value=5.055 –0.5

0.0 0.5 1.0

X-ray X-ray + tomography Implant

Fig.5–Boxplotoftheinterobserverkappaconcordance relatingtochoiceofimplant.

Table4–Interobserverkappaindexatbothtimesin

relationtoSchatzker’sclassification,accessrouteand

implant.

Time1vs. Time2

Schatzker Access Implant

kappa(p-value) kappa(p-value) kappa(p-value)

Observer1 0.35(0.044)a _0.36_(0.128) _0.36_(0.128) Observer2 0.85(<0.0001)a _0.35_(0.125) ₋_0.04_(0.707) Observer3 0.39(0.012)a _0.50_(0.049)a _0.67_(0.011)a Observer4 0.28(0.075) 0.83(0.002)a _0.15_(0.464) Observer5 0.49(0.005)a _0.26_(0.202) ₋_0.16_(0.521) Observer6 0.28(0.043)a _0.44_(0.037)a _0.12_(0.658) Observer7 0.28(0.071) 0.02(0.944) 0.11(0.573) Observer8 0.31(0.037)a _0.48_(0.067) _0.00_(1.000) Observer9 0.38(0.017)a _0.79_(0.007)a ₋_0.04_(0.658) Observer10 0.62(<0.0001)a _0.49_(0.058) ₋_0.10_(0.512)

Table5–Interobserverreproducibilityinrelationtothree-columnclassification.

Observers kappa(p-value) Observers kappa(p-value) Observers kappa(p-value)

1×2 0.29(0.118) 2×9 0.52(0.022)a ₅_×₆ _0.32_(0.131)

1×3 0.21(0.249) 2×10 0.53(0.011)a ₅_×₇ _1.00_(<0.0001)a 1×4 0.58(0.003)a ₃_×₄ _0.55_(0.011)a ₅_×₈ _0.57_(0.023)a 1×5 0.26(0.145) 3×5 0.53(0.009)a ₅_×₉ _0.66_(0.002)a 1×6 0.17(0.394) 3×6 0.41(0.064) 5×10 0.67(0.001)a 1×7 0.26(0.145) 3×7 0.53(0.009)a ₆_×₇ _0.32_(0.131) 1×8 0.12(0.460) 3×8 0.17(0.478) 6×8 0.31(0.154) 1×9 0.58(0.003)a ₃_×₉ _0.55_(0.011)a ₆_×₉ _0.39_(0.079) 1×10 0.44(0.028)a ₃_×₁₀ _0.30_(0.129) ₆_×₁₀ _0.40_(0.064) 2×3 0.37(0.104) 4×5 0.66(0.002)a ₇_×₈ _0.57_(0.023)a 2×4 0.52(0.022)a ₄_×₆ _0.39_(0.079) ₇_×₉ _0.66_(0.001)a 2×5 0.43(0.064) 4×7 0.66(0.002)a ₇_×₁₀ _0.67_(0.001)a 2×6 0.84(<0.0001)a ₄_×₈ _0.31_(0.154) ₈_×₉ _0.31_(0.154) 2×7 0.43(0.064) 4×9 1.00(<0.0001)a ₈_×₁₀ _0.34_(0.066) 2×8 0.41(0.108) 4×10 0.70(0.001)a ₉_×₁₀ _0.70_(0.001)a

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Observers

2 4 6 8 10

–1.0 –0.5

Concordance coefficient

Schatzker

Access management Implant management

Fig.6–Interobserverconcordancecoefficientrelatingto Schatzker’sclassificationandthechoiceofaccessrouteand implant.

intra-andinterobserverreproducibilityofSchatzker’s classi-fication,andthatitsroutineapplicationwasquestionable.

IncontrasttoWickyetal.16_and_Markhardt_et_al.,17_whose studies confirmed that CT showed tibial plateau fractures moreaccuratelyandenabledgreaterprecisionofpreoperative planning,therewasnostatisticallysignificantchangein rela-tiontooperativeplanninginthepresentstudyafterviewing theCT.

Luo etal.5 _proposed _using _a_three-column _{classification} fortibialplateaufracturesthatencompassedlesionpatterns thatwouldbedifficulttoclassifywiththemethodscurrently used.Fractures withposteriorfragmentsare notenvisaged inSchatzker’sclassification,whichmay makeit difficultto

1.0

0.5

0.0

–0.5

1.0

10 20 30 40

0

Comparisons between observers

Kappa concordance

Fig.7–Interobserverkappaconcordanceofthe three-columnclassification.

–0.5 p-value=0.003

Schatzker Three columns

Fig.8–Boxplotofinterobserverkappaconcordanceofthe Schatzkerandthree-columnclassifications.

diagnosethemandplanoperations.Inouranalysis,wefound that there was moderate interobserver concordancein the three-columnclassification.Thisclassificationmaybea use-fuloptioninmanagingtibialplateaufractures.

BecauseCTisunavailableinsomeservicesandbecauseof thehighcostofthisexaminationandthehighexposureto radiationthatisinvolved,thereisaneedfornewstudiesto clarifytherealvalueofCTinclassifyingandmanagingtibial plateaufractures.

Studieswithlargersamplesandbroaderapproachesneed tobedevelopedsothatroutineuseofCTandthepresent clas-sificationsystemsformanagingtibialplateaufracturescanbe judgedmoremeaningfully.

Conclusion

UseofCTdidnotgiverisetogreaterconcordancebetween theevaluatorsregardingSchatzker’sclassification.Nordidit contributetowardschangesinpreoperativeplanningin com-parisonwithradiographs.

Thethree-columnclassificationpresentedmoderate inter-observer concordance and might be a useful option in approachestowardstibialplateaufractures.

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

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