Rev. bras. ortop. vol.49 número2

(1)

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

Original

Article

Radiological

analysis

on

femoral

tunnel

positioning

between

isometric

and

anatomical

reconstructions

of

the

cruciate

ligament

夽

,

夽夽

Rodrigo

Barreiros

Vieira

∗

_,

_Leonardo

_Augusto

_de

_Pinho

_Tavares,

Rodrigo

Campos

Pace

Lasmar,

Fernando

Amaral

da

Cunha,

Lucas

Araujo

de

Melo

Lisboa

OrthopedicsandTraumatologyService,FaculdadedeCiênciasMédicasdeMinasGerais,HospitalUniversitárioSãoJosé,BeloHorizonte, MG,Brazil

a

r

t

i

c

l

e

i

n

f

o

Articlehistory:

Received24February2012 Accepted8February2013 Availableonline25March2014

Keywords:

Knee

Anteriorcruciateligament Reconstructivesurgicalprocedures

a

b

s

t

r

a

c

t

Objective:theaimofthisstudywastoradiologicallyevaluatethefemoraltunnelposition inanteriorcruciateligament (ACL)reconstructions usingtheisometricandanatomical techniques.

Methods:aprospectiveanalyticalstudywasconductedonpatientsundergoingACL recon-structionbymeansoftheisometricandanatomicaltechniques,usinggraftsfromtheknee flexortendonsorpatellartendon.Twenty-eightpatientswererecruitedduringthe immedi-atepostoperativeperiod,atthekneesurgeryoutpatientclinicofFCMMG-HUSJ.Radiographs oftheoperatedkneewereproducedinanteroposterior(AP)viewwiththepatientstanding onbothfeetandinlateralviewwith30◦_of_flexion._The_lines_were_traced_out_and_the dis-tancesandanglesweremeasuredonthelateralradiographtoevaluatethesagittalplane. Thedistancefromthecenterofthescrewtotheposteriorcorticalboneofthelateralcondyle wasmeasuredanddividedbytheBlumensaatline.Inrelationtotheheightofthescrew,the distancefromthecenterofthescrewtothejointsurfaceofthelateralcondyleoftheknee wasmeasured.OntheAPradiograph,evaluatingthecoronalplane,theanglebetweenthe anatomicalaxisofthefemurandalinetracedatthecenterofthescrewwasmeasured.

Results:withregardtothepmeasurement(posteriorizationoftheinterferencescrew),the testsshowedthatthep-value(0.4213)wasgreaterthanthesignificancelevelused(0.05); thenullhypothesiswasnotrejected anditcouldbestated thatthere wasno statisti-callysignificantdifferencebetweentheanatomicalandisometrictechniques.Withregard totheHmeasurement(heightofthescrewinrelationtothelowercorticalboneofthe knee),thep-valueobserved(0.0006)waslessthanthesignificancelevelused(0.05);the nullhypothesiswasrejectedanditcouldbestatedthattherewasastatisticallysignificant differencebetweentheanatomicalandisometrictechniques.Itcanbeconcludedthatthe

夽

Pleasecitethisarticleas:VieiraRB,dePinhoTavaresLA,PaceLasmarRC,daCunhaFA,deMeloLisboaLA.Análiseradiológicado posicionamentodotúnelfemoralcomastécnicasdereconstruc¸ãoisométricaoudereconstruc¸ãoanatômicadoLCA.RevBrasOrtop. 2014;49:160–166.

夽夽

WorkperformedattheFaculdadedeCiênciasMédicasdeMinasGerais,HospitalUniversitárioSãoJosé(FCMMG-HUSJ),BeloHorizonte, MG,Brazil.

∗ _{Corresponding}_author_.

E-mail:[email protected](R.B.Vieira).

(2)

latterdifferenceoccurredbecausetheisometrictechniquegeneratedgreatervaluesforthe Hmeasurementthantheanatomicaltechnique.WithregardtotheMEDvariable(positionof thescrewontheAPradiograph),theobservedp-value(0.000)waslessthanthesignificance level(5%);thenullhypothesiswasrejectedanditcouldbestatedwith95%confidencethat therewasasignificantdifferencebetweentheanatomicalandisometrictechniques.

Conclusions: therewerestatisticallysignificantdifferencesintheradiologicalevaluations ofthe femoraltunnel,both inthe sagittaland inthecoronal plane,betweentheACL reconstructiontechniques.

Análise

radiológica

do

posicionamento

do

túnel

femoral

com

as

técnicas

de

reconstruc¸ão

isométrica

ou

de

reconstruc¸ão

anatômica

do

LCA

Palavras-chave:

Joelho

Ligamentocruzadoanterior Procedimentoscirúrgicos reconstrutivos

r

e

s

u

m

o

Objetivo:avaliarradiologicamenteaposic¸ãodotúnelfemoralnareconstruc¸ãodoligamento cruzadoanteriorpelastécnicasisométricaeanatômica.

Métodos: foifeitoestudoanalíticoprospectivoempacientessubmetidosàreconstruçãodo ligamentocruzadoanterior(LCA),pormeiodatécnicaisométricaeanatômica,comousode enxertodetendõesflexoresdojoelhooudetendãopatelar.Foramcaptados28pacientes,em pós-operatórioimediato,noambulatóriodecirurgiadojoelhodaFCMMG-HUSJ.Foramfeitas radiografiasdojoelhooperadonasincidênciasemanteroposterior(AP)comapoiobipodálico eperfilem30◦_de_flexão._Foram_traçadas_as_linhas_e_medidos_os_ângulos_e_as_distâncias naradiografiaemperfilparaavaliaroplanosagital.Foimedidaadistânciadocentrodo parafusoàcorticalposteriordocôndilolateraledivididopelalinhadeBlumensaat.Com relaçãoàalturadoparafuso,foimedidaadistânciadocentrodeleatéasuperfíciearticular docôndilolateraldojoelho.NaradiografiaemAP,queavaliaoplanocoronal,mede-sea angulaçãoentreoeixoanatômicodofêmureumalinhatraçadanocentrodoparafuso.

Resultados: pelostestes,op-valor(0,4213)émaiordoqueoníveldesignificânciaadotado (0,05),ahipótesenulanãoérejeitadaepodeserafirmadoquenãohádiferença estatistica-mentesignificativaentreastécnicasanatômica(TAN)eisométrica(TIS)noquedizrespeito àMedidaP(posteriorizaçãodoparafusodeinterferência).Comoop-valor(0,0006)observado émenordoqueoníveldesignificânciaadotado(0,05),rejeita-seahipótesenulaepodeser afirmadoquehádiferençaestatisticamentesignificativaentreaTANeaTISnoquediz respeitoàMedidaH(alturadoparafusoemrelaçãoàcorticalinferiordojoelho).Pode-se concluirqueessadiferençaocorreporqueaTISgeravaloresmaioresparaaMedidaHdo queaTAN.Comoop-valorobservado(0,000)émenordoqueoníveldesignificância(5%), rejeitou-seahipótesenulaeafirmamoscom95%deconfiançaquehádiferençasignificativa entreaTANeaTISnoquedizrespeitoàvariávelMED(posiçãodoparafusonaradiografia emAP).

Conclusões: houvediferençaestatisticamentesignificativanaavaliaçãoradiológicadotúnel femoral,tantonoplanosagitalcomonocoronal,entreastécnicasdereconstruçãodoLCA. ©2014SociedadeBrasileiradeOrtopediaeTraumatologia.PublicadoporElsevier EditoraLtda.Todososdireitosreservados.

Introduction

Reconstructionoftheanteriorcruciateligament(ACL)isone ofthe most frequently performed orthopedicsurgical pro-ceduresanditparticularlyaffectsyoungadults.Ithasbeen estimatedthatbetween75,000and100,000suchprocedures are carried out in the United States every year.1

Reestab-lishmentofkneebiomechanicsisthemainobjectiveofthe treatment, inorder toavoidearly degenerative alterations, with consequent reduction in work capacity and sports performance.

Overrecentdecades,thearthroscopicprocedureof intra-articularACLreconstructionhasbeen consideredtobethe

gold standardtreatmentbecauseofits lowmorbidity,with betterandfasterpostoperativeevolution.

In the 1990s, it was believed that the isometric arthro-scopic reconstruction technique forthe ACL, in which the neoligament maintains its lengththroughout the range of motionoftheknee,wouldmoreadequatelyrestorethe biome-chanicsofthisjoint.Thiswasachievedbyconstructingthe femoraltunnelatanorientationofcloseto12o’clock,which would make the graft vertical. Although this concept was partially true, with restoration of translational stability, a recent study revealed afailureto reachrotationalstability, withmaintenanceofthepivotshift.2_{Consequently,}_the_joint

(3)

In2003,Yasudaetal.3_were_the_first_of_several_authors_to

studyanatomicalACLreconstructioningreaterdepth,with constructionofafemoraltunnel,ortunnelsinthecaseofa doubleband,atthepointwherethesebandsoriginate,inthe medialwallofthelateralfemoralcondyle.Somemorerecent studieshaveshownthat,withthisprocedure,both transla-tionalandrotationalstabilityareachieved,thusreproducing thebiomechanicalcharacteristicsofthekneefaithfully.4–6

Withregardtoevaluatingthepositioningofthefemoral tunnelaftertheoperation,therearesomestudiesinthe liter-atureshowingthatthisobjectivecanbeestablishedthrough radiologicalstudies.7–9

The aim of this study was to radiologically evaluate thepositionofthe femoraltunnelusingthe isometricand anatomicalreconstructiontechniques.

Materials

and

methods

Aprospectiveanalyticalstudywasconductedon28patients who underwent ACL reconstruction using grafts from the flexortendonsofthe kneeorfrom thepatellar tendon.All the procedures were performedby the same author (RBV). Fourteen patients underwent isometric reconstruction and theother14patientsunderwentanatomicalreconstruction; patients were allocated randomly. All ofthe patients were evaluated,beforeandaftertheoperation,atthekneesurgery outpatientclinic ofSão José University Hospital, School of MedicalSciences of MinasGerais(HUSJ-FCMMG), and they underwentthesurgicalprocedureinthesamehospital.The patients included in this study presented a condition of anteriorkneeinstabilitythathadbeendiagnosedboth clin-icallyandbymeans ofmagneticresonance examination,a closedgrowth plate intheproximaltibia anddistalfemur, and an age of less than 50 years. All the patients were referredthroughtheBrazilianNationalHealthSystem(SUS). We excluded patients who required corrective osteotomy during the reconstructive procedure, those with advanced osteoarthrosisandthosewithinjuriestoperipheralligament structuresoftheknee.Inthissample,27weremenandone wasawoman,andthemeanagewas32.5years(range:16–48). Therewere16patients(57.14%)withinjuriestotheleftknee and 12 (42.86%) to the right knee. All the patients under-wentradiologicalexaminationswithinthefirstpostoperative month.

Withfollow-upfromoneoftheauthors,thepatientswere referredforimagingexaminationsintheradiologysectorof HUSJ-FCMMG.Radiographswereperformed in anteroposte-rior(AP)viewontheoperatedknee,withweight-bearingon bothfeet,andinlateralviewatflexionof30◦_._These

exami-nationsweredulyidentifiedwiththepatient’sname,thedate ofthesurgeryandthetechniqueused(isometricor anatomi-cal).Wetracedoutthelinesandmeasuredthedistancesand anglesinthefollowingmanner:onthelateralradiograph,the distancesfromthecenterofthescrewtotheposteriorcortical boneofthelateralcondyleandfromthecenterofthescrew totheanteriorcorticalboneweremeasured(Fig.1).In rela-tiontotheheightofthescrew,thedistancefromthecenter ofthescrewtothejointsurfaceofthelateralcondyleofthe kneewasmeasured(Fig.1).OntheAPradiograph,theangle

Fig.1–Theposteriorizationoftheinterferencescrew (measurementP)wasmeasuredbydividingthedistance betweenpoints1and2(posteriorcorticalbonetothe centerofthescrew)bythedistancebetween1and3(center ofthescrewtotheanteriorcorticalbone).Theheightofthe screwinrelationtothelowercorticalboneoftheknee (measurementH)wasalsomeasured,bymeansofthe distancebetween2and5.

betweentheanatomicalaxisofthefemurandalinetraced throughthecenterofthescrewwasmeasured(Fig.2).

Results

Table1presentsadescriptiveanalysisonthemeasurements P and H from the lateral view, stratified according to the technique used: anatomical technique (ANT) or isometric technique(IST).Itcouldbeseenthat,onaverage,thevalues

Table1–DescriptivestatisticsforthemeasurementsP andHaccordingtothetechniqueused.

Technique MeasurementP MeasurementH

ANT IST ANT IST

Count 14 14 14 14

Mean 0.4556 0.4352 0.2023 0.3119

Standarddeviation 0.1236 0.0835 0.1224 0.0583

Minimum 0.2370 0.3320 0.0570 0.2270

Firstquartile 0.3662 0.3858 0.1430 0.2615

Median 0.4525 0.4045 0.1855 0.3065

Thirdquartile 0.5435 0.4688 0.2122 0.3668

(4)

Fig.2–Theanglebetweentheanatomicalaxisofthefemur andthecenterofthescrewwasmeasuredin

anteroposterior(AP)view.TheangleMEDwasdefined.

foundformeasurementPusingANTwereslightlylargerthan thosefoundusingIST.Thesamewasfoundwiththestandard deviationsandmedians.

InthecaseofmeasurementH,it couldbeseenthatthe valuesfoundthroughusingISTwereonaveragegreaterthan thoseusingANTandalsopresentedlower variability,since thestandarddeviationwassmaller.

Fig.3showsahistogramofthe distributionof measure-mentPforANTandIST.ForANT,therewasaveryirregular distribution,andforIST,thedistributionwasasymmetricalto theright.

Fig.4showsahistogramofthe distributionof measure-mentHforANT andIST.Itcanbeseenthatthevaluesfor

ANThadasymmetricaldistributiontotheright,whileforIST, thedistributionwasapproximatelyuniform.

FromtheboxplotpresentedinFig.5, itcanbeseenthat thedistributionofmeasurementPwasconcentratedonclose valuesbothforANTandforIST.Aswasseenintheinitial descriptiveanalysis,theboxplotmadeitpossibletoseethat therewaslessvariabilityinISTthaninANT,sincethe“box” wassmaller.

RegardingmeasurementH,thedistributionofthevalues forANT wasconcentrated onsmallervaluesthan thoseof IST.Thisindicatesthattheremaybeasignificantdifference betweenthesetwotechniquesinrelationtomeasurementH. Tocheckthishypothesis,anappropriatestatisticaltestwas performed.

Fig. 6 presents a plot of the individual values of each measurement, to compare ANT and IST. Thisgraph ledto conclusionssimilartothosefromtheprecedinggraph.

Sinceasmallsamplewasusedtocomparemeasurements PandHinrelationtothetechniqueusedand,moreover,itwas seenthroughastatisticaltestthattheassumptionofnormal distribution ofthe datawasviolated, themostappropriate statisticaltestforevaluatingthe hypothesisofinterestwas thenonparametricMann–Whitneytest.

Thehypothesestobetestedwereasfollows:

Test1:measurementP.

H0:ANTandISTpresentthesamedistribution.

Ha:ANTandISTpresentdifferentdistributions.

Test2:measurementH.

H0:ANTandISTpresentthesamedistribution.

Ha:ANTandISTpresentdifferentdistributions.

Thesignificancelevelusedwas˛=0.05.

Test1:measurementP.

Estimateddifference:median(ANT)–median(IST)=0.0355. Confidenceintervalforthisdifference:(−0.0520;0.1050).

p-Value=0.4213.

Therefore,sincethep-value(0.4213)wasgreaterthanthe significance level used (0.05), the null hypothesis was not rejectedanditcouldbestatedthattherewasnostatistically significant difference betweenANT and IST withregard to measurementP.

9

8

7

6 5

4

3

2

1

0

0.4 0.3

0.3

0.4 0.5 0.6 0.7

0.7 0.6 0.5

Measurement P

ANT

Frequency

IST

(5)

Measurement H

ANT

Frequency

IST

0.08 0.16 0.24 0.32 0.40 0.48 0.56

6

5

4

3

2

1

0

0.08

0.16

0.24

0.32

0.40

0.48

0.56

Fig.4–HistogramofthemeasurementH,stratifiedaccordingtotechnique.

ANT IST Measurement P Technique

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0.0

Measurement

Measurement H ANT IST

Fig.5–BoxplotofthemeasurementsPandHaccordingto thesurgicaltechniqueused.

Test2:measurementH.

Estimateddifference:median(ANT)–median(IST)=−0.1275. Confidenceintervalforthisdifference:(−0.1820;−0.0710).

p-Valor=0.0006.

Sincethep-value(0.0006)wassmallerthanthesignificance levelused(0.05),thenullhypothesiswasrejectedanditcould bestatedthattherewasastatisticallysignificantdifference betweenANTandISTwithregardtomeasurementH.Itcould beconcludedthatthisdifferenceoccurredbecauseIST gener-atedlargervaluesformeasurementHthanANTdid.

AccordingtoTable2,thepatientsonwhomISTwasused presentedgreatermean valuesforthe variable MED,inAP view,andsmallervariability.

ItcanbeseenfromFig.7thatthemeasurementsobserved forthevariableMEDwereapparentlygreaterforthepatients onwhom ISTwas applied.However,ahypothesistestwas neededinordertoascertainwhetherthisdifferencewas sta-tisticallysignificant.

Fig.8showsthatthepatientsonwhomANTwasusedhad lowervaluesforthevariableMEDandgreatervariabilitythan thepatientsonwhomISTwasused.Again,thisprovedthe needforahypothesistestinordertoascertainwhetherthis differencewasstatisticallysignificant.

Measurement P Measurement H

Technique

Measurement

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0.0

ANT IST

Fig.6–IndividualvaluesforthemeasurementsPandH, accordingtothetechnique

50

40

30

20

10

ANT IST

Technique

MED

Fig.7–BoxplotforthevariableMED.

(6)

Table2–DescriptivestatisticsforthevariableMED.

Variable Technique N Mean Standarddeviation Minimum Q1 Median Q3 Maximum

MED ANT 14 26.93 8.51 12.00 20.75 27.50 31.25 42.00

IST 14 42.21 6.78 25.00 39.00 42.00 48.50 51.00

50

Technique

MED

40

30

20

10

ANT IST

Fig.8–IndividualvaluesforMED.

therewasasignificantdifferencebetweenANTandISTwith regardtothevariableMED.

It could also be stated, with 95% confidence, that the patientsonwhomISTwasappliedpresentedresultsforMED thatonaveragewere16.74times[CI(21.93;11.55)]greaterthan amongthosewithANT.

Discussion

The importance of correct positioning of both the tibial and the femoral tunnel in ACL reconstruction cannot be underestimated. Poor positioning of the tunnels is a very common mistake in ACL reconstruction, and the possible problemsincludediminishedrange ofmotionofthe knee, graftfailure,impactingofthegraftontheintercondylarroof and continuation of feelings of instability, which generate revisionsurgicalproceduresthat oftenpresentmajor com-plexity. Since the center of rotation of the knee is closer tothefemoralinsertionthan tothetibialinsertion,greater accuracyoftunnel placement in the femur, in ACL recon-struction, is more critical than tibial tunnel positioning.10

For this reason, our study onlyaddressed analysis of this tunnel.

Inmostorthopedicsurgicalproceduresinvolvingthebone structure, radiological parameters that have already been welldefinedguidecriticalanalysisontheircorrectnessand the possible technical mistakes that could affect the final result.ThisisnotthecasewithregardtoACLreconstruction; althoughsomestudiesintheworldwideliteraturehaveshown differentmethodsforradiologicallypositioningofthefemoral tunnel,9–12_none_of_them_has_been_shown_to_be_effective_or_has

becomewidelydisseminated.

Overafive-yearfollow-upon89patientswhounderwent ACLreconstructionusingvideo-assistedarthroscopy,Aglietti etal.13_demonstrated_that_88%_of_the_knees_with_correct

posi-tioningofthefemoraltunnelpresentedsatisfactorystability. However,anteriorpositioningofthefemoraltunnelwas asso-ciatedwithafailurerateof62.5%.Khalfayanetal.14_showed

that 79%ofthe caseswithpositioning ofthe femoral tun-nelentrancewithintheposterior40%portionofthe lateral condyleofthe femurpresentedgood resultsusingthe KT-1000arthrometer(upto3mmofanteriorization).Inourstudy, theISTcameclosertotheresultsofthepreviousauthor,with ameanof0.4352or43%posteriortothemeasurement, ver-sus0.4556or45%,and thuswasslightlymoreanteriorized. Thisisthereasonwhy,withthesingle-bandANT,thefemoral tunnelwasconstructedatthebifurcatedcrest,betweenthe insertionsofthefibersoftheanteromedialandposterolateral bandsoftheACL,i.e.alittlemoreanteriorizedthanwhatwas usedinalltheotherarticlesanalyzed,whichusedthe antero-medialbandasthepointatwhichthetunnelshouldbemade inthefemur.

Inourstudy,itwasshownthatintworegardsofthe posi-tioning(heightandangleinthefrontalplane),thetranstibial accessproducedresultsthatweresignificantlydifferentfrom thoseobtainedusingamedialportal.Thisdivergesfromthe studybyGironetal.,inwhichtheystatedthattheyreachedthe “ideal”pointonthefemurboththroughanout-inortranstibial accessandthroughananteromedialapproach.15

Recently,Shahetal.16_conducted_a_radiographic_evaluation

on43patientswhounderwentanatomicalACLreconstruction usingtheanteromedialportaltechniqueandtheyfoundthat theinterferencescrewwaslocatedonthefemurat approxi-mately31%ofthesagittaldiameterinrelationtotheposterior corticalboneandat25%oftheheightofthelateralfemoral condyle.

Inaradiographicanalysisonbonetunnelpositioningin ACLreconstructionthatcomparedtheopentechniquewith arthroscopyviaananteromedialportal,Dambrósetal.8_found

adifferencebetweenthetwotechniquesregardingthe posi-tioningofthefemoraltunnel.Thearthroscopicrouteshowed greaterprecisionintunnelpositioning,andthisdifferencewas showntobestatisticallysignificant.Wealsoobserveda differ-enceinourstudyinrelationtofemoraltunnelpositioning,but weonlyusedarthroscopictechniques.

Bernardetal.17_demonstrated_that_the_positioning_of_the

interferencescrewinthecondylewasat28.5%oftheheight ofthe lateral femoralcondyle, using thequadrant method describedintheiroriginalstudy,whichusedtheanteromedial portaltechnique.

Inourresult,inmeasuringtheheightofthelateralfemoral condyleinrelationtotheBlumensaatline, themeanvalue forISTwas20.2%andforANTwas31.1%.Functional evalu-ationswithlong-termfollow-upareneededinordertomake comparisonsregardingthebestsurgicaltechnique,since con-clusionscannotbereachedusingradiographicevaluationof tunnelposition.

Inrelationtothefrontalplane,ourcalculationsshowed that the mean difference between the tunnel angles was 16.74◦_. _The _angle _in _the _anatomical _{reconstruction} _was

(7)

byAgliettietal.,18_who_in₁₉₉₅_published_a_paper_showing_a

differenceof18◦_between_the_tunnels.

Furtherimagingstudiescorrelatedwithfunctionalstudies arestillawaited,inordertoaffirmwhichradiographic param-etersarecorrectforfemoraltunnelpositioning.

Certainlimitationsofthepresentstudyneedtobe high-lighted.Theradiographsthatwereanalyzedinrelationtoour patientswereproducedusingdifferentradiologytechniques, withfollow-upbyoneoftheauthors.Consequently,theywere notperformedinablindedmanner,whichmighthaveledto bias.Therealpositioningofthegraftinsidethebonetunnel couldnotbecompletelyviewedontheradiographicimaging; onlythe positioningofthe screwcouldbeseen.Lastly,the samplesizewassmall.

Conclusion

Thepositioningofthefemoraltunnelonradiological exami-nationpresentedresultsthatwereverysimilarinrelationto posteriorizationonthefemoralcondyle,independentofthe techniqueused.However,thereweresignificantdifferences inheightandangleinrelationtothefemoralaxis.

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

r

e

f

e

r

e

n

c

e

s

1. GriffinLY,AgelJ,AlbohmMJ,ArendtEA,DickRW,GarrettWE, etal.Non-contactanteriorcruciateligamentinjuries:risk factorsandpreventionstrategies.JAmAcadOrthopSurg. 2000;8(3):141–50.

2. JonssonH,Riklund-AhlströmK,LindJ.Positivepivotshift afterACLreconstructionpredictslaterosteoarthrosis:63 patientsfollowed5-9yearsaftersurgery.ActaOrthopScand. 2004;75(5):594–9.

3. YasudaK,KondoE,IchiyamaH,KitamuraN,TanabeY, TohyamaH,MinamiA.Anatomicreconstructionofthe anteromedialandposterolateralbundlesoftheanterior cruciateligamentusinghamstringtendongrafts. Arthroscopy.2004;20(10):1015–25.

4. YagiM,WongEK,KanamoriA,DebskiRE,FuFH,WooSL. Biomechanicalanalysisofananatomicanteriorcruciate ligamentreconstruction.AmJSportsMed.2002;30(5):660–6.

5. GabrielMT,WongEK,WooSL,YagiM,DebskiRE.Distribution ofinsituforcesintheanteriorcruciateligamentinresponse torotatoryloads.JOrthopRes.2004;22(1):85–9.

6.VanEckCF,LesniakBP,SchreiberVM,FuFH.Anatomic single-anddouble-bundleanteriorcruciateligamentreconstruction flowchart.Arthroscopy.2010;26(2):258–68.

7.KondoE,YasudaK,IchiyamaH,AzumaC,TohyamaH. Radiologicevaluationoffemoralandtibialtunnelscreated withthetranstibialtunneltechniqueforanatomic double-bundleanteriorcruciateligamentreconstruction. Arthroscopy.2007;23(8):869–76.

8.DambrósJM,FlorêncioR,LopesJúniorOV,KuhnA,SagginJ, SpinelliLF.Análiseradiológicadoposicionamentodostúneis ósseosnacirurgiadereconstruc¸ãodoligamentocruzado anterior:comparac¸ãoentreastécnicasabertaeartroscópica viaportalanteromedial.RevBrasOrtop.2001;46(3):

270–5.

9.AgliettiP,ZaccherottiG,MenchettiPP,DeBiaseP.A

comparisonofclinicalandradiologicalparameterswithtwo arthroscopictechniquesforanteriorcruciateligament reconstruction.KneeSurgSportsTraumatolArthrosc. 1995;3(1):2–8.

10.GuoL,YangL,WangAM,WangXY,DaiG.Roentgenographic measurementstudyforlocatingfemoralinsertionsiteof anteriorcruciateligament:acadavericstudywithX-Caliper. IntOrthop.2009;33(1):133–7.

11.AmisAA,BeynnonB,BlankevoortL,ChambatP,ChristelP, DurselenL,etal.ProceedingsoftheESSKAscientific workshoponreconstructionoftheanteriorandposterior cruciateligaments.KneeSurgSportsTraumatolArthrosc. 1994;2(3):124–32.

12.HarnerCD,MarksPH,FuFH,IrrgangJJ,SilbyMB,MengatoR. Anteriorcruciateligamentreconstruction:endoscopicversus two-incisiontechnique.Arthroscopy.1994;10(5):

502–12.

13.AgliettiP,BuzziR,GironF,SimeoneAJ,ZaccherottiG. Arthroscopic-assistedanteriorcruciateligament reconstructionwiththecentralthirdpatellartendon.A 5-8-yearfollow-up.KneeSurgSportsTraumatolArthrosc. 1997;5(3):138–44.

14.KhalfayanEE,SharkeyPF,AlexanderAH,BrucknerJD,Bynum EB.Therelationshipbetweentunnelplacementandclinical resultsafteranteriorcruciateligamentreconstruction.AmJ SportsMed.1996;24(3):335–41.

15.GironF,BuzziR,AgliettiP.Femoraltunnelpositioninanterior cruciateligamentreconstructionusingthreetechniques.A cadaverstudy.Arthroscopy.1999;15(7):750–6.

16.ShahAA,BrienA,LoweWR.Radiographicresultsoffemoral tunneldrillingthroughtheanteromedialportalinanterior cruciateligamentreconstruction.Arthroscopy.

2010;26(12):1586–92.

17.BernardM,HertelP,HornungH,CierpinskiT.Femoral insertionoftheACL.Radiographicquadrantmethod.AmJ KneeSurg.1997;10(Winter(1)):14–21.