Rev. bras. ortop. vol.50 número3

r e v b r a s o r t o p . 2015;50(3):266–269

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

Original

Article

Reproducibility

of

the

AO/ASIF

and

Gartland

classifications

for

supracondylar

fractures

of

the

humerus

in

children

夽

Igor

Tadeu

Silveira

Rocha

_,

_André

_de

_Siqueira

_Faria,

_Carlos

_Fontoura

_Filho,

Murilo

Antônio

Rocha

UniversidadeFederaldoTriânguloMineiro(UFTM),Uberaba,MG,Brazil

a

r

t

i

c

l

e

i

n

f

o

Articlehistory: Received2April2014 Accepted15May2014 Availableonline28May2015

Keywords: Fracturesofthe humerus/classification Children

Observer-dependentvariations Reproducibilityofresults

a

b

s

t

r

a

c

t

Objective:ToevaluatethereproducibilityoftheradiographicclassificationsofGartlandand theAssociationforOsteosynthesis/AssociationfortheStudyofInternalFixation(AO/ASIF) forsupracondylarfracturesofthehumerusinchildren.

Methods:Ontwooccasions,50radiographsinanteroposteriorandlateralviewswere evalu-atedbythreepediatricorthopedistsinaccordancewiththeGartlandandAO/ASIFpediatric classifications.Their responses weresubjectedto statisticalanalysisconsisting of cal-culationofthecoefficienttoassesstheintra-andinterobserverconcordance,inboth classifications.

Results:Thestrengthoftheintraobserverconcordancewashighornearperfectforthethree examinersinthetwoclassificationsystems.Thestrengthoftheinterobserverconcordance washighinthetwosystems,withcoefficientsof0.756fortheGartlandclassificationand 0.766fortheAO/ASIFclassification.

Conclusion:TheGartlandandAO/ASIFclassificationsystemsshowedsimilarreproducibility andperformance.Highstrengthofconcordancewasseenintheintra-andinterobserver analyses.

©2014SociedadeBrasileiradeOrtopediaeTraumatologia.PublishedbyElsevierEditora Ltda.Allrightsreserved.

Reprodutibilidade

das

classificac¸ões

AO/ASIF

e

Gartland

para

fraturas

supracondilianas

de

úmero

em

crianc¸as

Palavras-chave:

Fraturasdoúmero/classificac¸ão Crianc¸a

r

e

s

u

m

o

Objetivo:Avaliarareprodutibilidadedasclassificac¸õesradiográficasdeGartlande Associa-tionforOsteosynthesis/AssociationfortheStudyofInternalFixation(AO/ASIF)parafraturas supracondilianasdeúmeroemcrianc¸as.

夽

WorkdevelopedintheDisciplineofOrthopedicsandTraumatology,UniversidadeFederaldoTriânguloMineiro,Uberaba,MG,Brazil. ∗ _{Correspondingauthor.}

E-mails:[email protected],[email protected](I.T.S.Rocha). http://dx.doi.org/10.1016/j.rboe.2015.05.001

rev bras ortop.2015;50(3):266–269

267

Variac¸õesdependentesdo observador

Reprodutibilidadedosresultados

Métodos: Emduasocasiõesforamavaliadasportrêscirurgiõesortopedistaspediátricos50 radiografiasnasincidênciasanteroposterioreseperfildeacordocomasclassificac¸õesde GartlandeAO/ASIFpediátrica.Asrespostasforamsubmetidasàanáliseestatísticapelo cálculodocoeficiente␬paraavaliaraconcordânciaintra-einterobservador,emambasas classificac¸ões.

Resultados:Aforc¸adeconcordânciaintraobservadorfoigrandeouquaseperfeitaparaostrês examinadoresnosdoissistemasdeclassificac¸ão.Aforc¸adeconcordânciainterobservador foigrandenosdoissistemas,comcoeficiente␬de0,756paraclassificac¸ãodeGartlandede 0,766paraclassificac¸ãoAO/ASIF.

Conclusão: Ossistemasdeclassificac¸ãodeGartlandeAO/ASIFmostraram reprodutibili-dadeedesempenhosimilar.Observou-segrandeforc¸adeconcordâncianasanálises intra-einterobservador.

©2014SociedadeBrasileiradeOrtopediaeTraumatologia.PublicadoporElsevier EditoraLtda.Todososdireitosreservados.

Introduction

Supracondylar fractures are the commonesttype of elbow fracturesinchildrenandthesecondcommonesttypeof frac-tureduringchildhood,accountingformorethan60%ofthe cases.1–4_{Theyoccurmostfrequentlybetweentheagesoffive} andtenyears.5_{Thevariousclassificationsystemsproposed} forthesefractureshavehad theaimsofguidingthe treat-ment,estimatingtheprognosisandenablingstandardization and comparisonamongthe many scientific studies.These classificationsneedtobesimple,easytoapplyclinicallyand reproducible, with high concordance between surgeons.6–8 TheGartlandclassificationforsupracondylarfracturesofthe humerusistheonemostused.9,10_{Inthisclassificationsystem,} fracturesaregroupedaccordingtotheirdegreeof displace-ment.

AlthoughtheLaGrange11_{classificationismoredescriptive} anddetailed incasesofgreaterdisplacement,it isnotthe systemmostused.

Inturn,thesystemadoptedbytheAOgroup12_forfractures ofthelongbonesinchildrencombinestheclassificationof Mulleretal.13_{foradultswithanadditionaldescriptionfocused} ontheimmatureskeleton.8_{Thisisanalphanumericsystem} thatincludestheboneaffected,thelocationandthe sever-ity,along withthe peculiaritiesofthe growingbone.Thus, supracondylarfractureswouldbedescribedas13-/9.1withan endingofI_,II_,III_orIV_{,accordingtowhetherthefracturewas} completeorincomplete,andwithorwithoutcontactbetween thefragments.Inthismanner,onlytheexceptioncomponent (I–IV)ofthemorphologicalsegmentoftheAO/ASIF classifica-tionwastakenintoconsiderationinthepresentstudy.

Theobjectiveofthisstudywastoassessthereproducibility oftheGartlandandAO/ASIFclassificationsfor supracondy-larfracturesofthehumerusinchildren,byinvestigatingthe levelsofintra-andinterobserverconcordance.

Methods

Thisstudywasconductedinareferralhospitalthatattends orthopedictraumacases,afterreceiving approvalfrom the institution’sethicscommittee.Fiftyconventionalradiographs

(anteroposterior and lateral views) originating from initial attendance ofpatients withsupracondylar fractures ofthe humerus, produced between January and June 2013, were selectedforevaluation.

Theradiographicimagesforthe studywere obtainedby meansofhigh-resolutiondigitalphotography,with preserva-tionoftheoriginalcharacteristicsofthefilm.

Theselectiondidnottakeintoconsiderationthequality oftheradiography.Imagesfrompatientsovertheageof16 years,fromthosewhopresentedaclosedgrowthplateline andfromthosepresentingmultiplefracturesonradiographs wereexcluded.Theimageswereevaluatedbythreepediatric orthopedistswhohadhadpreviousaccesstothe classifica-tionsystems.Sevendaysoftrainingbeforetheanalysiswas permitted.

Theexaminersevaluatedthe50imagesoveramaximum time oftwo hoursandmade asecond evaluationwiththe sameduration,twoweekslater.Theorderofthe50images was variedthrough randomization.Theexaminers didnot haveaccesstotheresponsesoftheirpeersortotheirown responsesgivenonthepreviousoccasion.

Theresponsesgivenbyeachexaminertotheradiographic evaluationswerewrittenonaprintedchartthatwashanded out toeach participant, together witha freeandinformed consentstatement.

Theresultswere gatheredandanalyzedwith theaidof theSPSS® _{software,version12.0(Chicago,USA),inorderto} determinethecoefficient,whichinferredthedegreeof con-cordancebeyondwhatwouldbeexpectedonlybychance.The strength oftheintra-andinterobserver concordanceofthe

Table1–Associationbetweenthecoefficientandthe strengthofconcordance.14

coefficient Strengthofconcordance

Lessthanzero Poor

0–0.20 Negligible

0.21–0.40 Slight

0.41–0.60 Moderate

0.61–0.80 High

268

Table2–Intraobserverconcordancelevelaccordingto thecoefficient,inrelationtotheGartlandandAO classificationsforsupracondylarfracturesofthe humerusinchildren.

Gartland AO

Examiner1 0.781 0.767

Examiner2 0.859 1

Examiner3 0.719 0.782

Table3–Interobserveranalysisoncoefficientfor Gartlandclassification.

GartlandI _GartlandII _GartlandIII

0.945 0.535 0.677

p-Valueof <0.001 <0.001 <0.001

95%confidence intervalof

Upper:1.0 Upper:0.695 Upper:0.837

Lower:0.785 Lower:0.375 Lower:0.517

twoclassificationsystemswasthendetermined,asdetained inTable1.14

Results

The intraobserver concordance according to the coeffi-cient,relatingtotheGartlandclassificationforsupracondylar fracturesofthehumerusinchildrenandtheAO/ASIF clas-sificationforfractures inchildren,aspresentedinTable2, washighoralmostperfectforalltheexaminersinrelation tobothclassifications.For twoofthethree examiners,the concordancefortheAO/ASIFsystemwasslightlyhigher.

Tables3and4presenttheinterobserveranalysesforthe GartlandandAOclassifications,respectively.Itcanbeseen thattheinterobserverconcordancedecreasedwithregardto categoryII,inbothclassificationsystems.

AsshowninTable5,theinterobserverevaluationshowed of0.756 for the Gartland classification and 0.766 forthe

AO/ASIFclassification,whichthusshows highconcordance betweenthetwosystems.

Discussion

Thediversityofclassificationsystemsforagroupoffractures thatispublishedoverthecourseoftimemaygiveriseto inter-pretationalconflicts.

Thus,thevalidity,reproducibilityandcorrelationsof well-established classifications need to be verified, given that comparisonsbetweendifferentevaluations,withexclusionof causalityandpersonalbias,candemonstratethequalitiesor weaknessesofagivensystemunderexamination.According toAudigéetal.,6_{fortheseobjectivetobeattained,the} clas-sificationsystemneedstogothroughthreeresearchphases beforeitisvalidatedforclinicaluse.6,14

Toknowwhetheragivencharacterizationorclassification foranobjectisreliable,thisobjectneedstobeevaluated sev-eraltimes,bymorethanoneexaminer.Forthis,inthepresent study,thecoefficientwasused.Thisinfersthedegreeof con-cordancebeyondwhatwouldbeexpectedpurelybychance. Itisbasedonthenumberofconcordantresponses,i.e.the numberofcasesforwhichtheresultisthesameamongthe examiners.15,16

In thepresent study,the examinersseemed tobe“well calibrated”,bothwithinthemselvesandwiththeothers.The interobserverconcordancevalueswerewithinthe95% con-fidenceinterval,withp<0.001inbothclassificationsystems. Therefore,thesevaluespresentedstatisticalsignificance.As alsofoundbyBrandãoetal.,14_{ourinterobserverconcordance} indexwasnogreaterthan0.8,eventhoughtheobserverswere allpediatricorthopedists.

TheconcordancefoundbetweentheGartlandandAO/ASIF classificationsystemswas satisfactory(high oralmost per-fect). These systems had similar performance, despite the greatercomplexityoftheAO/ASIFsystemandtheexaminers’ lowerdegreeoffamiliaritywiththissystem.

Inthepresentstudy,theloweststrengthofconcordance (moderate)intheinterobserveranalysiswasfoundintypeIIof theGartlandandAO/ASIFclassifications.However,according toHealetal.,10_{thelowestlevelofinterobserverconcordance} fortheGartlandclassificationoccurredintypeI.

Itwasobservedthatvariationsinthedegreeof concord-anceintheinterobserveranalysisofdifferentstudies10,14_did

Table4–InterobserveranalysisoncoefficientforAOclassification.

AOI _AOII _AOIII _AOIV

0.865 0.435 0.75 1.0

p-Valueof <0.001 <0.001 <0.001 <0.001

95%confidenceintervalof Upper:1.0 Upper:0.595 Upper:0.91 Upper:1.0

Lower:0.705 Lower:0.275 Lower:0.59 Lower:0.84

Table5–Generalcoefficientforinterobserverevaluation,accordingtoclassificationsystem.

Numberofradiographs General Generalp-value 95%confidenceintervalof

Gartland 50 0.756 <0.001 Upper:0.874

Lower:0.637

AO/ASIF 50 0.766 <0.001 Upper:0.868

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notinvalidatetheconstantobservationthatthetwo classifi-cationshavegoodreproducibility.

Evaluationofthereproducibilityoftheseclassificationsis ofimportanceinsofarastheyguidethetypeoftreatment insti-tutedforthesefractures(conservativeversussurgical).They alsoenablestandardization ofthe orthopediclanguage for comparingstudiesfromdifferentcenters.

Nowthatthereproducibilityoftheseclassificationsystems hasbeen verified,it becomesnecessary toconduct further studiestoascertainwhetheroneofthemmightbesuperior totheotherandthustodetermineastandardsystem.

Conclusion

TheGartlandandAO/ASIFclassificationsystemsshowed sim-ilarreproducibilityandtheintra-andinterobserveranalyses showed high strength of concordance,even though use of theAO/ASIFsystemremainslimitedamongorthopedistsand, consequently,theirfamiliaritywiththismethodislower.

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

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