SOCIEDADE BRASILEIRA DE ORTOPEDIA E TRAUMATOLOGIA
w w w . r b o . o r g . b r
Original
Article
Reconstruction
of
the
medial
patellofemoral
ligament
by
means
of
the
anatomical
double-bundle
technique
using
metal
anchors
夽
David
Sadigursky
a,b,∗,
Matheus
Simões
de
Melo
Laranjeira
b,
Marzo
Nunes
a,
Rogério
Jamil
Fernandes
Caneiro
a,
Paulo
Oliveira
Colavolpe
aaClínicaOrtopédicaTraumatológica,Salvador,BA,Brazil
bFaculdadedeTecnologiaeCiências,Salvador,BA,Brazil
a
r
t
i
c
l
e
i
n
f
o
Articlehistory: Received5July2015 Accepted30July2015 Availableonline27April2016
Keywords: Ligamentpatellar Patellardislocation Patella
Knee
Reconstructivesurgicalprocedures
a
b
s
t
r
a
c
t
Objective:Toevaluatedouble-bundlereconstructionofthemedialpatellofemoralligament (MPFL)usingagraftfromthesemitendinosustendonandfixationwithmetalanchorsover themediumterm.
Methods:Thiswasaprospectivecross-sectionalstudy.Afterapprovalfromtheresearch ethicscommittee,31patientswithpatellofemoralinstabilitywhounderwentMPFL recon-structionbymeansoftheanatomicaldouble-bundletechnique,withfixationusingmetal anchors,wereanalyzedbetweenMay2010andJanuary2015.Toevaluatetheeffectiveness oftheMPFLreconstructionsurgery,theKujalascaleandtheTegner–Lysholmscorewere assessedbeforetheprocedureandoneyearafterwards,alongwithclinicaldatasuchas painlevels,rangeofmotionandJsign.ThedataweretabulatedintheExcel®softwareand wereanalyzedusingtheSPSSStatistics®software,version21.Thestatisticalanalysiswas performedusingtheWilcoxonTtestandtheMcNemartest.
Results:ThemeanpreoperativescorefromtheKujalatestwas45.64±1.24andthe post-operativescorewas94.03±0.79(p<0.001).The preoperativeTegner–Lysholm scorewas 40.51±1.61andthepostoperativescorewas91.64±0.79(p<0.001).Thepreoperativerange ofmotionwas125.96±2.11andthepostoperativerangewas138.38±1.49(p<0.05). Conclusion:MPFLreconstructionbymeansoftheanatomicaldouble-bundletechniqueis easilyreproducible,without episodesof recurrence,with satisfactory results regarding restorationofstabilityandfunctionofthepatellofemoraljoint.
©2015SociedadeBrasileiradeOrtopediaeTraumatologia.PublishedbyElsevierEditora Ltda.ThisisanopenaccessarticleundertheCCBY-NC-NDlicense(http:// creativecommons.org/licenses/by-nc-nd/4.0/).
夽
StudyconductedatClínicaOrtopédicaTraumatológica(COT),Salvador,BA,Brazil.
∗ Correspondingauthor.
E-mail:davidsad@gmail.com(D.Sadigursky).
http://dx.doi.org/10.1016/j.rboe.2015.07.011
Reconstruc¸ão
do
ligamento
patelofemoral
medial
pela
técnica
anatômica
do
duplo-feixe
com
âncoras
metálicas
Palavras-chave: Ligamentopatelar Luxac¸ãopatelar Patela
Joelho
Procedimentoscirúrgicos reconstrutivos
r
e
s
u
m
o
Objetivo:Avaliar,emmédioprazo,areconstruc¸ãodoligamentopatelofemoralmedial(LPFM) comduplo-feixecomenxertodotendãosemitendíneoefixac¸ãocomâncorasmetálicas. Métodos: Estudoprospectivodecortetransversal.Demaiode2010ajaneirode2015,após aprovac¸ãodocomitêdeéticaempesquisa,foramanalisados31pacientescominstabilidade patelofemoral,submetidosàcirurgiadereconstruc¸ãodoligamentopatelofemoralmedial (LPFM)comatécnicaanatômicadoduplo-feixecomfixac¸ãocomâncorasmetálicas.Para avaliaraeficáciadacirurgiadereconstruc¸ãodoLPFM,foramutilizadasaescaladeKujala eoescoredeTegner-Lysholm,antesdoprocedimentoeapósumano.Foramavaliadosos dadosclínicoscomooarcodemovimento,presenc¸adoSinaldoJeníveldedor.Osdados foramtabuladosnoprogramaExcel®eanalisadoscomoprogramaSPSSStatistics®versão 21.AanáliseestatísticafoifeitacomotesteTdeWilcoxoneotestedeMcNemar. Resultados: Amédiadosresultadosobtidosnopré-operatóriocomotestedeKujalafoide 45,64±1,24enopós-operatóriode94,03±0,79(p<0,001).Oescoredojoelhode Tegner-Lysholm alcanc¸adofoi de 40,51±1,61no pré-operatório, para91,64±0,79 (p<0,001)no pós-operatório.Oarcodemovimentoobtevemédiade12,596±2,11nopré-operatórioe 13,838±1,49nopós-operatório(p<0,05).
Conclusão: Areconstruc¸ãodoLPFMcomduplo-feixeéumatécnicadefácilreproduc¸ão,sem episódiosderecidiva,ecomresultadosadequadosparaarestaurac¸ãodaestabilidade.
©2015SociedadeBrasileiradeOrtopediaeTraumatologia.PublicadoporElsevier EditoraLtda.Este ´eumartigoOpenAccesssobumalicenc¸aCCBY-NC-ND(http:// creativecommons.org/licenses/by-nc-nd/4.0/).
Introduction
Patellardislocationisaverycommonconditionin orthope-dics.Itprimarilyaffectsyoungpatientsofbothsexes,witha higherincidenceinfemales,althoughinmales,casestendto bemoresevere.1
Recurrentpatellardislocationisdefinedastwoor more episodesofdislocation, orsymptoms ofpatellarinstability thatlastformorethanthreemonthsafterthefirstdislocation episode.2
Themedialpatellofemoralligament(MPFL)wasdescribed byConlanetal.3asthemajorrestrainttolateraldisplacement ofthepatella,accountingforapproximately53%ofthe resis-tance,andcontrollingitstrajectoryduringtheexecutionof thefullrangeofmotion.3,4Inmostpatients,thisligamentis rupturedduringacutepatellardislocation.5
Camanhoetal.6 demonstratedthatspecificMPFL recon-structionafterthedislocationepisodeleadstomorefavorable results when compared with conservative treatment, with lowerchanceofrecurrence.
Therefore,itisknownthatsurgicaltreatmentisnecessary torestorethepatellarstability.7Anumberofsurgical tech-niquesforMPFLreconstructionhavebeendescribedforthe treatmentofthiscondition.8
Despiteitsbiomechanicalimportance,thevalueofMPFL reconstructionhasonlyrecentlybeenacknowledged,mostly inthelasttwodecades.9Despitethewiderangeoftechniques describedforitsreconstruction,withdifferentgraftsources andfixationmethods,thereisgrowingevidenceofgood clin-icaloutcomes forthis surgery,butthereare stillimportant
unsatisfactoryresults,around12.5%,asinthefindingsof Sing-haletal.10Themaincomplicationafterreconstructionisjoint stiffnessandpainaftertheprocedure.
Onecauseofthiscomplicationisthenon-anatomicalgraft positioninginMPFLreconstruction.Itwasobservedthatsmall errorsofupto5mmfromtheidealpositionorexcessive ten-sioningofthegraft(>2N),causeanincreaseinthepressure forceson themedialaspectofthepatella.Thiscreatesthe needfortechniquesthatcanproperlydistributegrafttension onthepatellaandcloserreproductionoftheanatomy.11–13
Fromthemeanandmaximumflexion,Sandmeieretal.14 and Parkeret al.15 demonstratedthatisolated MPFL recon-struction was not able torestore normal patellar tracking. FailuretorestoreproperMPFLanatomyorisometrymaycause thisresultand,therefore,limitthesuccessforlonger follow-ups.13
Kangetal.16introducedtheconceptoffunctionalbundles oftheMPFL.Theligamenthasathinlayerthatconnectsthe femoralcondyle tothesuperomedial border ofthe patella. Theinferiorfibersactasastaticstabilizer,andthesuperior fibersactinthedynamicstabilizationofthepatella,dueto theircloserelationshipwiththetendonofthevastusmedialis obliquus.
Thekeytoachievingfavorablelong-termresultsis attach-ingthegraftinthemostanatomicalformpossible.However, theidealfixationmethodremainsamatterofdiscussion. Dif-ferentfixationmethodshavebeendescribed,suchasfixation bybonetunnels,internalbuttons,andanchors.17
Ithasbeen postulated thatclinical resultswiththe use of metalanchorsarecomparablewithpublishedpreviousdata regardinganatomicdouble-bundleMPFLreconstructionusing bonetunnelsinthepatella.10,19–23
Thisstudyaimedtoassesstheeffectivenessofanatomic double-bundleMPFLreconstructionusingthesemitendinosus andfixationwithmetalanchorsinthemedialborderofthe patella.
Material
and
methods
TheprospectivestudywasconductedfromMay2010to Jan-uary2015,afterapprovaloftheResearchEthicsCommittee via Plataforma Brasil. The study included 31 patients with patellofemoralinstabilitywhounderwent anatomic double-bundleMPFLreconstructionandfixationwithmetalanchors. All patients had history of more than two episodes of patellar dislocation, and were selected toundergo surgical MPFL reconstruction through the double-bundle technique describedbySongetal.,18usingY-shapedmetalanchorsin thepatella.21
Patientswereattendedinareferralorthopedicshospitalby theinstitutions’kneesurgerygroup.Theywereassessed pre-operativelyand12monthsaftertheprocedure.Thephysical examination was documented through the patellar appre-hension test, J-sign, and range of motion. To evaluatethe effectivenessofthereconstruction,theKujalaet al.24 clini-calandfunctionalquestionnaireswereapplied,aswellasthe Lysholm–Tegnerscores25;theywereappliedpre-and postop-eratively.
TheKujalascale24addressessymptomsrelatedtoanterior kneepain(patellofemoraldisorders).Itevaluatessubjective symptoms,suchaspainandfunctionlimitations,whichare scored from 0 to 100, according to the complaints of the patient; 100 represents the complete absence of pain and limitationsand0,constantpainandseverallimitations.The assessedparametersare:pain,claudication,patellar sublux-ation, walking,stair climbing, and staying seated for long periodswiththekneesbent.
TheLysholm–Tegner score25 consistsof eightquestions withclosedanswers.Eachquestion hasanassigned value, whicharethenadded.Thefinalresultisexpressedboth nom-inallyandordinally:“Excellent,”95–100points;“Good,”84–94 points;“Regular,”65–83points;and“Bad,”forscoresequalto orlessthan64.
Patients with recurrent patellar dislocation (over two episodes),agedlessthan45years(mean29years),andwith magneticresonanceimagingshowingextensiveruptureofthe medialpatellarstabilizerswithoutosteochondrallesionwere included.
Theexclusioncriteria comprisedpatientswith congeni-taldiseases;thosewithosteochondrallesionsofthepatella; those with distance between the anterior tibial tuberosity andtrochleargroove(ATT-TG) greater than20mm, indicat-ingmedializationoftheanteriortibialtuberosity(ATT);those olderthan 45 years;and thosewith inflammatoryor post-traumaticarthritis.
Nopatientunderwent furthertreatmentwithrelease of thelateralretinaculum,trochleoplasty,osteotomy,orcartilage
procedures. All patientswere assessedby medical history-taking,physicalexamination,radiographicassessments,and computedtomographyinthepreoperativeperiod.The patel-larheightwasmeasuredusingtheCaton–Deschampsindex26 andtrochleardysplasia,bytheDejouretal.classification.27
AsemitendinosustendongraftwasusedforMPFL recon-struction.Thefixationwasperformedwithtwo5-mmmetal anchorsinthepatellaandanY-shapedinterferencescrewin thefemur,forcreatingbothligamentbundlesandfixationin independentkneeflexionangles.16
Surgicaltechnique
Thepatientwasplacedinthedorsaldecubitusposition,under spinalanesthesia.Initially,anarthroscopywasperformedin theaffectedkneefortheidentificationofassociatedinjuries orremovalofintra-articulardebris.Lateralretinacularrelease wasnotperformed.
The semitendinosus tendonwas then resected through a 2–3-cm incision over the insertion of the pes anserinus tendons.Thefasciaofthesartoriusmusclewaspushedout throughanobliqueincision,andthetendonwasexposedand resected.Thesemitendinosustendonwasused,asitsgreater lengthandvolumeallowedforabettergraftmanipulation.
The point of graft fixation in the femur was identified withtheaidofprofileradioscopy,accordingtothe parame-tersdescribedbySchöttleetal.28Themedialapproachtothe femurwasperformedaftertheanatomicalpointwas identi-fied.Then,aguide-wire,anterior-andproximal-directed,was inserted,avoidingpenetrationintotheposteriorregionofthe femoralcondyle.
Afterconfirmingtheproperplacementoftheguide-wire,a tunnelwasdrilledwithapowerdrillofthesamediameteras thedoublegraft.Thefoldedsemitendinosustendongraftwas insertedthroughthefemoraltunnel(Fig.1),andfixedwithan interferencescrew(Fig.2).
Alongitudinalthirdincisionwasmadeunderthemedial border ofthepatella.29Thegrooveonthemedialborderof thepatellawascreatedabovethetransitionwiththeposterior chondralfaceofthepatellawiththeaidofacuretteto accom-modatethegraft.Two5-mmmetalanchorswereintroduced and positioned in the two proximal thirds of the patella, 10–15mm of the joint, with a distanceof 15mm between them.Themostdistalbundle,theinferior-straight(IS),was firstestablishedwiththepatellaatapproximately30◦ofknee flexion;then,themostproximalbundle,thesuperior-oblique (SO),atabout60◦offlexion,inaccordancewiththestudiesby Sadigurskyetal.30andStephenetal.13Theremainingmedial retinaculumwassuturedunderthetendon(Fig.3).
Afterfixation, thepatellarposition wasverifiedthrough arthroscopicimageandbythemobilityofthepatellaataround one-quarterofitssize.21
Postoperativeperiod
Fig.1–Afterthesemitendinosustendonwaspassed throughthefemoraltunnel,markedat30mmatthedistal end.
loadwasallowedastolerated.Exercisesinclosedkineticchain wereallowedfromthefourthweekaftersurgeryonwards.31
Contactsportsandrotationwereallowedaftersixmonths ofthesurgery.31
Statisticalanalysis
DataweretabulatedinExcel®forMacOSXandanalyzedusing SPSSStatistics®forMacOSX,version21.Categoricaldatawere
Fig.2–Passageofthegraftinthefemoraltunneland fixationwithmetallicinterferencescrew.
Fig.3–Fixationoftheinferior-straight(IS)bundle,followed bythesuperior-oblique(SO)atindependentkneeflexion angles,30◦and60◦,respectively.
presentedasproportionsandquantitativedataasmedians, means,andstandarddeviations.Statisticalanalysiswas per-formedwiththeWilcoxonTtestwithalphaerrorof0.05and McNemartest,alsowithalphaerrorof0.05.
Results
Table1describesthestudysample.Thestudyincluded31 sub-jects,withameanageof29.38andstandarddeviation(SD)of 8.11.Sixteenpatientswerefemale(51.6%),and15weremale (48.4%). Themostaffected knee was the right, in18 cases (58.06%);13subjects(41.9%)hadtheleftkneeaffected.
Thepatellarapprehensiontestwaspositiveinall31(100%) patients preoperatively, and it was negative in 31 (100%) postoperatively.TheJ-sign was positivein24 cases(77.4%) preoperativelyandnegativeinseven(22.6%);positiveinfive cases(16.1%)andnegativein26(83.9%)postoperatively.The Caton–Deschampsindexwaslessthanorequalto1in21cases (67.7%);itremainedbetween1.1and1.2infivecases(16.1%), andwasgreaterthanorequalto1.3infivepatients(16.1%). Eighteencases(58.1%)hadATT-TGbetween12and15mm;13 (41.9%),between15and20mm;andnocasehadATT-TGabove 20mm.Dejour typeAtrochleardysplasiawaspresentin14 subjects(45.2%);typeB,ineight(25.8%);typeC,intwo(6.5%);
Table1–Sociodemographicdescription.
Variable N(%) Mean±SD
Age 31 29.38±8.11
Sex
Male 15(48.4)
Female 16(51.6)
Affectedknee
Right 18(58.06)
Table2–Clinicaldatainthepre-andpostoperative period.
Variable PreoperativeN
(%)
PostoperativeN
(%)
Patellarapprehensiontest
Positive 31(100) 0
Negative 0 31(100)
J-sign
Positive 24(77.4) 5(16.1)
Negative 7(22.6) 26(83.9)
Caton–Deschamps(mean±SD) 1.01±0.17
≤1.0 21(67.7) –
1.1–1.2 5(16.1) –
≥1.3(high) 5(16.1) –
ATT-TG(mean±SD) 15.4±0.19
12–15mm(normal) 18(58.1) –
15–20mm(high) 13(41.9) –
>20 0 –
Trochleardysplasia
A 14(45.2) –
B 8(25.8) –
C 2(6.5) –
Zero 7(22.6) –
andsevenpatientsdidnotpresent anydegreeofdysplasia (22.5%).ThesefindingsarepresentedinTable2.
ThemeanpreoperativeKujalascore24was45.64(SD:1.24; median: 49); the post-operative mean was 94.03 (SD: 0.79; median:96), withstatistical significanceofp=0.001. Inthe categorizedanalysisofthescore,31(100%)subjectspresented apoorpreoperativescore,andallsubjects(100%)presented agood/excellent post-operativescore. Themean preopera-tiveLysholm–Tegner25scorewas40.51(SD:1.61;median:43) thepostoperativemeanwas91.64(SD0.79;median:90),with statisticalsignificanceof0.001.Table3presentsthefindings fromthequestionnaires.Additionally,nopatient(100%) pre-sentedrecurrence.Themeanpostoperativerangeofmotion was138.38±1.49,andthemeanpreoperativerangeofmotion was125.96±2.11,withstatisticalsignificance(p<0.05).
Table4–Pre-andpostoperativepatellarapprehension testscores.
Patellarapprehensiontest
Preoperative Postoperative p
Absent Present
Present 31 0 0.001
Absent 0 31
Table4showstheanalyticalrelationshipbetweenthe pre-andpostoperativepatellarapprehensiontest.Thedifference betweentheseresultswasstatisticallysignificant(p<0.05).
TheMcNemartestwasalsoappliedtotheJ-signratioin both moments (pre- and postoperative), and astatistically significant difference in the periods studied was observed (Table5).
Discussion
Fromthe1990sonwards,MPFLreconstructionhasbecomethe techniqueofchoicebymostauthors.32Exceptincaseswhere ATT-TGisabove20mm,orincasesoftrochleardysplasiawith supratrochlearspurabove5mm,isolatedMPFLreconstruction hasbeenproventobeasuitableandeffectivetechniquefor thecorrectionofpatellarinstability.33Hopperetal.,34when assessing72patients,proposedthatisolatedMPFL reconstruc-tionshouldnotbeperformedinpatientswithseveretrochlear dysplasia.Inoverhalfofpatients,amildtomoderatetrochlear dysplasia wasidentified, but it was foundnottoinfluence theresults.PatientswithDejourtypeDtrochleardysplasia27 wereexcludedfromthisstudy.Oftheselectedpatients,eight (25.8%)hadtypeBdysplasia,butwithoutsupratrochlearspurs above5mm.
Thisfinding is similarto thosebyArendt35 and Steiner etal.,36whoobservedgoodresultsinpatientswithtrochlear dysplasiawhounderwentisolatedMPFLreconstruction.The postoperativerangeofmotionimprovedby15◦inthemedian and12◦inthemean.Thep-valuewasstatisticallysignificant.
Table3–Surgicalandclinicalscores.
Variable PreoperativeN
(%)
PostoperativeN
(%)
pa
Rangeofmotion (median/mean±SD)
125/125.96±2.11 140/138.38±1.49 0.1
Kujalascore
(median/mean±SD)
49/45.64±1.24 96/94.03±0.78 0.001
Poor 31(100) 0
Regular 0 0
Good/excellent 0 31(100)
Lysholmscore 43/40.51±1.61 90/91.64±0.79 0.001
Poor 31(100) 0
Regular 0 0
Good 0 18(58.1)
Excellent 0 13(41.9)
Table5–Pre-andpostoperativeJ-sign.
J-sign
Preoperative Postoperative pa
Absent Present
Present 5 19 0.001
Absent 0 7
a McNemartest,consideredsignificantwhenp<0.05.
In2009, Kang et al.16 described the anatomy and func-tion ofbothMPFL bundles.TheSO bundle,along withthe vastusmedialis obliquus, tracks the kneecapmedially and promotesadynamicconstraint.Inturn,the ISbundleacts asstaticrestrainttobalancetheresultinglateralforces act-ingonthepatella.Thus,thereconstructionofbothbundles couldincreasethestabilityduringthefirstflexionanglesand above30◦ofkneeflexion,whichwouldallowfortension main-tenanceduringthemovementarc,promotedbyeachbundle independently.
Philippotetal.37describedtheroleofthemedial stabiliz-ingligamentsofthepatella,medialpatellotibial(MPTL)and medialpatellomeniscal(MPML),whichpresenttheirhighest performanceatanglesabove45◦ofkneeflexion.The recon-structionofMPTLhasbeengainingpopularityinpatientsboth inthegrowthphase(withopenphysis)andadults.38–40 Dur-ingthemovementarc,fromthetotallength(0◦)to90◦flexion, theMPTLandMPMLcontributewith28%and48%againstthe lateralizationofthepatella,23%and71%againstinclination, and32%and92%againstrotation,respectively.Thisfinding cannotbedisregardedwhenplanningthecorrectionof patel-larinstability.37,38 However,despitethe growing interest in MPTLreconstruction,inordertodecreasethedisplacement ofthepatellaathigheranglesofflexion,possibly eliminat-ingtheinvertedJ-sign,todatethereisnodataprovingthe superiorityoftheclinicalresultsincombineddouble-bundle reconstructionoftheMPTLandMPML.37,39
ThefixationofMPFLbundlesatdifferentangles(theIS bun-dleat0◦ andthe OSat30◦)wassuggestedbyKanget al.41 However,theauthorsbelievethattheOSbundleshouldbe fix-atedat60◦withminimaltension,andtheISbundleataround 30◦,basedonthestudiesbySadigurskyetal.30andHanetal.,20 inordertopreventoverpressureinthemedialaspectofthe patellaand,consequently,anteriorkneepain.Stephenetal.13 demonstratedthattheanatomicalreconstructionpositioned witha2-Ntensionunderthegraft,fixedat30◦or60◦ofknee flexion,restoresnormalcontactpressureinthelateral patel-laraspectaswellasitsappropriateflexion-extensionpath. Songetal.,42inabiomechanicalstudy,demonstratedthatthe lengthoftheMPFLfibersvarieswiththedegreeofkneeflexion. Thesuperiorfibers reachtheirmaximumlengthatsmaller angles;theinferiorfibers,atgreaterflexionangles.
Theauthors observedimprovementsin patellar sublux-ation at around 20◦ to 30◦ of knee flexion, demonstrated through negative results in the apprehension test. The invertedJ-signwaspositivein24patients(77.4%) preopera-tivelyandinonlyfive(16.1%)postoperatively.Thefivepatients (16.1%)whoseCaton–Deschampsindexwasgreaterthan1.3, whichcharacterizedhighpatella,showedthepersistenceof
the J-sign, confirming this asafactor ofpoor prognosisin isolated MPFL reconstruction regarding the persistence of residualsubluxationofthepatellainkneeflexionanglesabove 45◦.
Inameta-analysisconductedbySinghaletal.,10a persis-tentpatellarinstabilitywasobserved,fromsubtletofrank,in around4.6%ofcasespostoperatively.Stiffnesswasthemost frequentcomplication(30%).However,theattachmentofthe double-bundlegraftwasmadeinthesameangleandunder thesametension.Inthiscase,theprocedureisperformedby initiallyfixatingthepatella.ThisC-shapedgraftfixation tech-niquecouldleadtoworseoutcomes,withincreasedrestriction ofnormalpatellarmobility.Kangetal.21,41demonstratedthat Y-shapedgraftfixation,whichstartsinthefemur,followedby fixationofeachbundleindependently,canimprovepatellar functionandreducepossiblecomplications.43
Through the Kujala24 and Lysholm–Tegner scores,25 the effectivenessofdouble-bundle MPFL reconstruction canbe demonstrated. The results show a recovery of the biome-chanical function of the patella. The mean Kujala score24 increasedfrom45.64preoperativelyto94.03postoperatively. In theLysholm–Tegner,25 therewas anincreasefrom 40.51 preoperativelyto91.64postoperatively.Ofthe31patients,18 (58.1%)movedto“good”and13patients(41.9%)to“excellent” outcomes.Theseresultsareveryclosetothosefoundinthe meta-analysisbySinghalet al.,10 but withfewer complica-tions.
Based on experimental and anatomical studies, the authorsarguethatMPFLreconstructionshouldbemadeboth isometricallyandanatomically.10,22 Giventheresultsofthis study,aswellasthosebyWangetal.,22MPFLreconstruction shouldbeperformedanatomically,withindependentfixation ofbothbundles.16,21,41
In this study, it was observed that the double-bundle MPFLreconstructionusingsemitendinosustendongraftand fixationwithmetalanchorsinindependentflexionangles pre-sentedfavorableresults,withoutrecurrenceepisodes,pain, oroverloadinthepatellofemoraljoint,andwithsatisfactory rangeofmotionandpossibilityofreturntopreviousactivities. Aweaknessofthestudywasthefactthatitwasconducted atasinglecenter,withoutacomparisongroupusingother correctiontechniquesforpatellarinstability.Nonetheless,the presentsamplewasveryclosetothatofstudieson double-bundleMPFLreconstructionintheliterature.5,7,8,10
Conclusion
Double-bundleMPFLreconstructionusingfixationwithmetal anchorsandindependentbundlefixationwas showntobe effectivebythe resultsobserved inthis study,suchasthe significantimprovementinthe scoreofthe protocols used withoutrelapseepisodesandthereductionofsubluxationat anglesabove45◦ofkneeflexion.
Conflicts
of
interest
Theauthorsdeclarenoconflictsofinterest.
Acknowledgements
To the members of the knee surgery group ofthe Clínica OrtopédicaTraumatológica(COT).
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