w w w . r b o . o r g . b r
Original
article
Clinical-radiographic
correlation
of
the
femoral
insertion
point
of
the
graft
in
reconstruction
of
the
medial
patellofemoral
ligament
夽
Lúcio
Flávio
Biondi
Pinheiro
Júnior
∗,
Marcos
Henrique
Frauendorf
Cenni,
Oscar
Pinheiro
Nicolai,
Guilherme
Galvão
Barreto
Carneiro,
Rodrigo
Cristiano
de
Andrade,
Vinícius
Vidigal
de
Moraes
HospitalMaterDei,BeloHorizonte,MG,Brazil
a
r
t
i
c
l
e
i
n
f
o
Articlehistory:
Received11September2014 Accepted14October2014 Availableonline16October2015
Keywords:
Patellardislocation Patellarligament Reconstruction
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c
t
Objective:Toanalyzetheradiographicpositioningofthefemoraltunnelandcorrelatethis withthepostoperativeclinicalresultsamongpatientsundergoingreconstructionofthe medialpatellofemoralligament(MPFL)alone.
Method:Thiswasaretrospectivestudyinwhich30kneesof26patientswithrecurrent dis-locationofthepatellathatunderwentMPFLreconstructionwereevaluated.Thefemoral insertionpointofthegraftandthepostoperativeclinicalconditionwereanalyzed and correlatedusingtheKujalaandLysholmscales.
Results:22kneespresentedafemoraltunnelintheanatomicalarea(groupA)and8outside ofthislocation(groupB).IngroupA,themeanscoreontheKujalascalewas89.68points andontheLysholmscalewas92.45points.IngroupB,themeanscoreontheKujalascale was84.75pointsandontheLysholmscalewas92points.Thedifferencebetweenthemeans wasnotsignificantoneitherofthetwoscales.
Conclusion:Correlationwiththeclinicalresultsdidnotshowanydifferenceinrelationto thepositioningofthefemoralinsertionofthegraft.
©2015SociedadeBrasileiradeOrtopediaeTraumatologia.PublishedbyElsevierEditora Ltda.Allrightsreserved.
Correlac¸ão
clínico-radiográfica
do
ponto
de
inserc¸ão
femoral
do
enxerto
na
reconstruc¸ão
do
ligamento
patelofemoral
medial
Palavras-chave: Luxac¸ãopatelar Ligamentopatelar Reconstruc¸ão
r
e
s
u
m
o
Objetivo:Analisaroposicionamentoradiográficodotúnelfemoralecorrelacioná-locomos resultadosclínicosnopós-operatórioempacientessubmetidosàreconstruc¸ãoisoladado ligamentopatelofemoralmedial(LPFM).
夽
WorkperformedintheKneeGroupofBeloHorizonte,HospitalMaterDei,BeloHorizonte,MinasGerais,Brazil. ∗ Correspondingauthor.
E-mail:luciobiondi@terra.com.br(L.F.B.PinheiroJúnior). http://dx.doi.org/10.1016/j.rboe.2015.10.003
Método:Estudoretrospectivo,emqueforamavaliados30joelhosde26pacientescomquadro deluxac¸ãorecidivantedapatelasubmetidosàreconstruc¸ãodoLPFM,analisadose correla-cionadosopontodeinserc¸ãofemoraldoenxertoeoquadroclínicopós-operatóriopelas escalasdeKujalaeLysholm.
Resultados: Apresentaramtúnelfemoralnaáreaanatômica(grupoA)22joelhoseoitofora desselocal(grupoB).NogrupoA,apontuac¸ãomédiapelaescaladeKujalafoide89,68e peladeLysholmfoide92,45.NogrupoB,apontuac¸ãomédiapelaescaladeKujalafoide 84,75epeladeLysholmfoide92.Adiferenc¸aentreasmédiasnãofoisignificativanasduas escalas.
Conclusão: Nãohouvediferenc¸aderesultadosclínicoscorrelacionadosaoposicionamento dainserc¸ãofemoraldoenxerto.
©2015SociedadeBrasileiradeOrtopediaeTraumatologia.PublicadoporElsevier EditoraLtda.Todososdireitosreservados.
Introduction
Themedialpatellofemoralligament(MPFL)isastripof reti-nacular tissue that connects the medial epicondyle ofthe femurto the medialborder of the patella. Several studies haveshown thatthe MPFL isthe primary restrictorof lat-eral patellardisplacement and themain agentresponsible for avoiding patellar dislocation, thus contributing 50–80% of the medial containment.1,2 According to Amis et al.,3 the MPFLhas mean tensile strength of208N,although, as demonstrated byMountney et al.,4 its limited capacity for stretchingresultsintotalruptureincasesofcompletepatellar dislocation.
Incases ofrecurrent dislocationofthe patella, surgical treatmentisindicated,giventhatanatomicalreconstruction oftheMPFLisessentialforrestorationofpatellarstability.3,5–7 Thus,severaltechniquesforMPFLreconstructionhavebeen developed,mostlywithreplacementofthetornligamentbya tendongraft.8–10
Several studies have identified the location of the MPFL3,11,12 and it isbelieved thatanatomical restorationis essentialforreproducingthenormalisometryand function oftheligament.13,14 Boneandradiographicparametersmay helpthesurgeontoadequatelyverifythepositioningofthe reconstructedligament.
Thefemoral isometric point makesthe greatest contri-bution towards the isometry ofthe MPFL and isthe most importantfactorforsuccessofthesurgery.However,its repro-ductionismoredifficultandmoresubjecttofailure.3,15
Nonetheless, thereare few reports correlatingthe posi-tioningofthefemoraltunnelandtheclinicalconditionafter thereconstruction.Througharetrospectivestudyonpatients whounderwentMPFLreconstruction,weaimedtoanalyzethe positioningofthefemoraltunnel,bymeansofradiographs, andtocorrelatethiswiththeclinicalresultsandfunctional scores.
Sample
and
method
BetweenJanuary2008and February2013,MPFL reconstruc-tionwasperformedon30kneesin26patients(9menand17
women)presentingaconditionofrecurrentdislocationofthe patella.Thepatients’meanageatthetimeofthesurgerywas 25.8years,witharangefrom16to46years.Therightkneewas affectedin13cases,whiletheleftkneewasaffectedin17.The minimum follow-up wassevenmonthsand the maximum was62 months,withameanof24.3months.Acorrelation wasmade betweenthe femoralinsertionpoint ofthegraft (assessedbymeansofsimpleradiographyoftheknee)and thepostoperativeclinicalcondition(assessedbymeansofthe KujalaandLysholmscales.
The inclusion criterion was that the patients selected neededtopresentobjectivepatellofemoralinstability.Patients with an open growth plate, patellofemoral arthrosis or alterations ofthe anteriortibialtuberosity-trochlear groove (ATT-TG)distanceorpatellarheightthatrequiredadditional proceduresfordistalpatellarrealignmentwereexcludedfrom the study.Patientswithassociatedlesionson theoperated limbthatmightdirectlyorindirectlyinfluencethefinalresult werealsoexcluded.
Three surgeons (LFBPJ, MHFC and OPN) performed the reconstructionsusinggraftsfromthesemitendinosustendon. Atransversetunnelwasconstructedintheupper-middlethird ofthepatella.Thefemoraltunnellocation wasdetermined bymeansofpalpationoftheanatomicalmarksbetweenthe tubercleoftheadductorsandthemedialepicondyle(Nomura point)15orbymeansoffluoroscopy,attheintersectionofa linetangentialtothemedialcondyleanditsperpendicularat theprojectionoftheposteriorcorticalbone,i.e.themethod ofSchöttleetal.,16accordingtothesurgeon’spreference.The graftwasfixedinthefemoraltunnelusingarhombusmetal screworabsorbableinterferencescrew,withthekneeflexed at30–45degrees.
Proximal
Point 1
Point 2
Distal Line 3 Line 2
Fig.1–FemoralpositioningusingthemethodofSchöttle.
anatomicalarea,according tothe radiographicpointofthe femoralinsertionofthegraft.
Inthe statisticalanalysis, tocompare themeans ofthe scores obtained by the above groups, the Wilcoxon non-parametric test was used, since this would not need the assumptionofnormalityofthescoremeasurements. Differ-encesbetweenthemeanswereconsideredtobesignificantif thep-valuesobtainedwerelessthan0.05.Theanalyseswere performedintheRfreesoftware,version3.0.1.
This study was approved by our institution’s research ethicscommitteeunderthenumber CAAE19486313.6.0000. 5128.
Results
GroupAcomprised20patientsand22knees.Themeanscore obtainedusingtheKujalascalewas89.6points,witharange
from64to100.AccordingtotheLysholmscale,themeanscore was92.4points,witharangefrom77to100,whichtranslated as11excellent,8goodand3fairresults.Noneoftheresults wereconsideredpoor.
GroupBcomprised8patientsand8knees.Themeanscore reachedontheKujalascalewas84.7points,witharangefrom 57to98.AccordingtotheLysholmscale,themeanscorewas 92points,witharangefrom76to100,whichtranslatedas4 excellent,3goodand1fairresult.JustasingroupA,noneof theresultswereconsideredtobepoor.Themaingraft fixa-tionerrorswereanteriorpositioningin37.5%ofthecasesand superiorpositioningin62.5%ofthecases.
Table 1 shows the descriptive statistics and p-valuesof comparisontestsonthemeanscoresobtainedviatheLysholm scale forgroupsAand B.Themean forgroupAwas92.45 (standard deviation=6.58). The mean for group B was 92 (standarddeviation=8.80).Thedifferencebetweenthemeans wasnotsignificant(p=0.8967).
Table 2 presents the descriptive statistics and p-values of comparison tests on the mean scores obtained via the KujalascaleforgroupsAandB.ThemeanforgroupAwas 89.68(standarddeviation=9.87).ThemeanforgroupBwas 84.75(standarddeviation=14.27).Thedifferencebetweenthe meanswasnotsignificant(p=0.4109).
Table3showstheresultfromthescoresobtainedbythe entiregroupwithoutseparation.
Fourpatientsunderwentreconstructionbilaterally.Twoof thempresentedthetunnelwithintheanatomicalregionin bothknees.In theother two,atunnelthatwas satisfacto-rilylocatedwasonlyobtainedononeside,buttherewereno differencesintheresultsfromthefunctionalscores.
Discussion
Several authorshaveadvocatedreconstructionofthe MPFL asthetreatmentforpatellarinstability,insteadofproximal
Table1–DescriptivestatisticsonthescoresobtainedviatheLysholmscale.
Participants Statistics p-Value
n Minimum Maximum Mean Standarddeviation
GroupA 22 77 100 92.45 6.58 0.8967
GroupB 8 76 100 92.00 8.80
Table2–DescriptivestatisticsonthescoresobtainedviatheKujalascale.
Participants Statistics p-Value
n Minimum Maximum Mean Standarddeviation
GroupA 22 64 100 89.68 9.87 0.4109
GroupB 8 57 98 84.75 14.27
Table3–Descriptivestatisticsonthescoresobtainedusingthetwoscales,withoutseparationaccordingtogroups.
Scales Statistics
n Minimum Maximum Mean Standarddeviation
Lysholm 30 76 100 92.33 7.08
realignment.17–20Independentofthetechniqueused, recon-structionoftheMPFLhasproducedgoodpatellarstability.Ina reviewarticle,Lindetal.21observedthatpost-reconstruction recurrencewasabsentfromfiveoftheeightstudies,whilein theremainingthree,therecurrentdislocationrateswerelower than7%,whichcanbeconsideredtobeasuccess,giventhat inotherpatellarstabilizationprocedures,therecurrent dislo-cationrateshavebeenreportedtobe10–35%.7Inthepresent studytoo,therewasnorecurrenceofpatellardislocation.
JustlikeServienetal.,22weusedtheradiographicmethod ofSchöttleetal.16inthepresentstudytopre-establishthe femoralinsertionpointofthegraft,withmodificationofthe zoneof5mmindiameterto±7mm,becauseofthediameter ofthefemoraltunnel.Thetunnelpositioningwasconsidered tobepoorwhenthiswasfoundtobeoutsideofanypartof thepointofSchöttleetal.16Goodpositioningofthefemoral fixation(groupA)wasobtainedin73.33%ofourcasesandpoor positioning(groupB)wasfoundin26.67%,andthisresultwas similartothatofServienetal.,22whofoundthat70%ofthe femoralpointswereinsidetheanatomicalregion.
McCarthyetal.23 conductedaretrospective study on50 patients who underwent reconstruction ofthe MPFL alone orinassociationwithdistalrealignment.Theseauthorsalso usedthemethodofSchöttleetal.16todeterminethe posi-tioningofthetunnel,andtheyevaluatedtheirpatientsusing the KOOS scale.In 36 cases (64%),the tunnel was consid-eredtobeoutsideoftheanatomicalposition.Their results were concordant withthose obtained inthe present study andbyServienetal.,22consideringthattherewasno statis-ticallysignificantdifferenceinthefunctionalscoresbetween thegroups,withregardtocomparisonswiththeanatomical positioninginthefemur.
Inthepresent study,it wasobservedthat86.36%ofthe resultsweregoodorexcellentaccordingtotheLysholmscale ingroupA,whiletheremainderpresentedfairresults(13.64%). None of the patients presented poor results. In group B, 87.5% of the patients presented good or excellent results. Theremainderpresentedfairresults(12.5%)andnoneofthe patientspresentedpoorresults.Theseresultsweresimilarto thoseobtainedbyServienetal.,22whodidnotfindany corre-lationbetweenthepositioningofthefemoraltunnelandthe IKDCanalysis.
Hopper et al.24 evaluated 72 knees in 68 patients who underwent MPFLreconstruction, using theKujala, Lysholm andTegnerscales.Theradiographicpositioningwasalso eval-uatedusingthemethodofSchöttleetal.16Itwasfoundthat46 patients(71.7%)presentedthefemoraltunnelinthe anatom-icalregion,andthiswasverysimilartowhatwasobtained in the present study and in the study by Servien et al.22 However,differingfromthepresentstudy,theresultswere sig-nificantlybetterinthepatientswithanatomicaltunnelsthan inthegroupinwhichthetunnelwasoutofposition(Kujala p=0.028;andLysholmp=0.012).Theseresultswereobtained after excluding patients with trochlear dysplasia from the evaluation.
It can be asked whether these poorly positioned tun-nelswouldleadtoincreasedincidenceofosteoarthrosisover the long term, giventhat inthese studies,in which simi-larresultswereobtainedbetweenthegroups,thefollow-up wasonlyovertheshortterm.Inabiomechanicalstudyon
cadavers, Stephen et al.25 demonstrated that poorly pos-itioned femoral tunnels that were proximal or distal in relationtotheiranatomicalpositionledtosignificantlygreater medial patellar contact pressure and medial patellar tilt during flexion–extension. This demonstrated the need for correctpositioningofthefemoraltunneltorestorethe nor-mal patellofemoral kinematics. Similar findings were also described by the same authors in another biomechanical study26andbyEliasandCosgarea14andBecketal.27
In our setting, Bitar et al.28 compared the resultsfrom reconstruction ofthe MPFL using the patellar tendonwith the results from conservative treatment forprimary patel-lardislocation.Theyobtainedbetterresultsfromthegroup thatunderwentsurgery.Thesurgicalgrouppresentedamean scoreof88.9ontheKujalascale,i.e.similartotheresultfrom thepresentstudy,whichwas88.3onthesamescale.Inthe surgicalgroupofthepreviousstudy,therewerenoreportsof recurrencesorsubluxation,justasinthepresentstudy.
Gonc¸alveset al.29 evaluated23 patientswhounderwent reconstructionoftheMPFLusingafreegraftfromthe semi-tendinosustendon.Afteraminimumfollow-upof24months, 22patientswereevaluatedusingtheKujalaandLysholm clin-icalprotocols.AccordingtotheLysholmprotocol,thepatients presenteda mean postoperativescore of93.36 points; and accordingtotheKujalaprotocol,the meanscorewas83.54 points. These results were similar to those shown in the presentstudy,with92.33and88.37,respectively.Likewise,it couldbeseenthatreconstructionofthemedialpatellofemoral ligament showedexcellent short-termresults,when evalu-atedusingclinicalprotocols.
Conclusion
Nocorrelationwasshowninthisstudybetweengoodfemoral radiographic positioning ofthe graft and betterfunctional clinical results,withregard toreconstructionofthemedial patellofemoralligament.However,cautionisneededin inter-preting these resultsbecause ofthe shortduration of the follow-up.
Conflicts
of
interest
Theauthorsdeclarenoconflictsofinterest.
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1.DesioSM,BurksRT,BachusKN.Softtissuerestraintsto lateralpatellartranslationinthehumanknee.AmJSports Med.1998;26(1):59–65.
2.PanagiotopoulosE,StrzelczykP,HerrmannM,ScuderiG. Cadavericstudyonstaticmedialpatellarstabilizers:the dynamizingroleofthevastusmedialisobliquusonmedial patellofemoralligament.KneeSurgSportsTraumatol Arthrosc.2006;14(1):7–12.
3.AmisAA,FirerP,MountneyJ,SenavongseW,ThomasNP. Anatomyandbiomechanicsofthemedialpatellofemoral ligament.Knee.2003;10(3):215–20.
afterrepairorreconstruction.JBoneJointSurgBr. 2005;87(1):36–40.
5. DavisDK,FithianDC.Techniquesofmedialretinacularrepair andreconstruction.ClinOrthopRelatRes.2002;(402):38–52. 6. NomuraE,InoueM.Surgicaltechniqueandrationalefor
medialpatellofemoralligamentreconstructionforrecurrent patellardislocation.Arthroscopy.2003;19(5):E47.
7. SandmeierRH,BurksRT,BachusKN,BillingsA.Theeffectof reconstructionofthemedialpatellofemoralligamenton patellartracking.AmJSportsMed.2000;28(3):345–9.
8. ElleraGomesJL,StiglerMarczykLR,CesardeCesarP,Jungblut CF.Medialpatellofemoralligamentreconstructionwith semitendinosusautograftforchronicpatellarinstability:a follow-upstudy.Arthroscopy.2004;20(2):147–51.
9. FithianDC,PaxtonEW,CohenAB.Indicationsinthe
treatmentofpatellarinstability.JKneeSurg.2004;17(1):47–56. 10.SmirkC,MorrisH.Theanatomyandreconstructionofthe
medialpatellofemoralligament.Knee.2003;10(3):221–7. 11.NomuraE,HoriuchiY,InoueM.CorrelationofMRimaging
findingsandopenexplorationofmedialpatellofemoral ligamentinjuriesinacutepatellardislocations.Knee. 2002;9(2):139–43.
12.NomuraE,InoueM,OsadaN.Anatomicalanalysisofthe medialpatellofemoralligamentoftheknee,especiallythe femoralattachment.KneeSurgSportsTraumatolArthrosc. 2005;13(7):510–5.
13.BicosJ,CarofinoB,AndersenM,SchepsisAA,FulkersonJP, MazzoccaA.Patellofemoralforcesaftermedial
patellofemoralligamentreconstruction:abiomechanical analysis.JKneeSurg.2006;19(4):317–26.
14.EliasJJ,CosgareaAJ.Technicalerrorsduringmedial patellofemoralligamentreconstructioncouldoverload medialpatellofemoralcartilage:acomputationalanalysis. AmJSportsMed.2006;34(9):1478–85.
15.SteensenRN,DopirakRM,McDonaldWG3rd.Theanatomy andisometryofthemedialpatellofemoralligament: implicationsforreconstruction.AmJSportsMed. 2004;32(6):1509–13.
16.SchöttlePB,SchmelingA,RosenstielN,WeilerA. Radiographiclandmarksforfemoraltunnelplacementin medialpatellofemoralligamentreconstruction.AmJSports Med.2007;35(5):801–4.
17.SchöttlePB,FucenteseSF,RomeroJ.Clinicalandradiological outcomeofmedialpatellofemoralligamentreconstruction withasemitendinosusautograftforpatellainstability.Knee SurgSportsTraumatolArthrosc.2005;13(7):516–21.
18.NomuraE,HoriuchiY,KiharaM.Medialpatellofemoral ligamentrestraintinlateralpatellartranslationand reconstruction.Knee.2000;7(2):121–7.
19.DrezDJr,EdwardsTB,WilliamsCS.Resultsofmedial patellofemoralligamentreconstructioninthetreatmentof patellardislocation.Arthroscopy.2001;17(3):298–306. 20.MunetaT,SekiyaI,TsuchiyaM,ShinomiyaK.Atechniquefor
reconstructionofthemedialpatellofemoralligament.Clin OrthopRelatRes.1999;(359):151–5.
21.LindM,JakobsenBW,LundB,ChristiansenSE.Reconstruction ofthemedialpatellofemoralligamentfortreatmentof patellarinstability.ActaOrthop.2008;79(3):354–60. 22.ServienE,FritschB,LustigS,DemeyG,DebargeR,LapraC,
etal.Invivopositioninganalysisofmedialpatellofemoral ligamentreconstruction.AmJSportsMed.2011;39(1):134–9. 23.McCarthyM,RidleyTJ,BollierM,WolfB,AlbrightJ,Amendola
A.Femoraltunnelplacementinmedialpatellofemoral ligamentreconstruction.IowaOrthopJ.2013;33:58–63. 24.HopperGP,LeachWJ,RooneyBP,WalkerCR,BlythMJ.Does
degreeoftrochleardysplasiaandpositionoffemoraltunnel influenceoutcomeaftermedialpatellofemoralligament reconstruction?AmJSportsMed.2014;42:716–22.
25.StephenJM,KaiderD,LumpaopongP,DeehanDJ,AmisAA. Theeffectoffemoraltunnelpositionandgrafttensionon patellarcontactmechanicsandkinematicsaftermedial patellofemoralligamentreconstruction.AmJSportsMed. 2014;42(2):364–72.
26.StephenJM,LumpaopongP,DeehanDJ,KaderD,AmisAA. Themedialpatellofemoralligament:locationoffemoral attachmentandlengthchangepatternsresultingfrom anatomicandnonanatomicattachments.AmJSportsMed. 2012;40(8):1871–9.
27.BeckP,BrownNAT,GreisPE,BurksRT.Patellofemoralcontact pressuresandlateralpatellartranslationaftermedial patellofemoralligamentreconstruction.AmJSportsMed. 2007;35(9):1557–63.
28.BitarAC,D’EliaCO,DemangeMK,ViegasAC,CamanhoGL. Estudoprospectivorandomizadosobrealuxac¸ãotraumática depatela:tratamentoconservadorversusreconstruc¸ãodo ligamentofemoropatelarmedialcomtendãopatelar.Mínimo dedoisanosdeseguimento.RevBrasOrtop.2011;46(6):675–83. 29.Gonc¸alvesMBJ,CarvalhoLHJr,SoaresLFM,Gonc¸alvesTJ,
SantosRL,PereiraML.Reconstruc¸ãodoligamento
