Oblique popliteal ligament - an anatomical study

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rev bras ortop.2013;48(5):402–405

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Original

Article

Oblique

popliteal

ligament

–

an

anatomical

study

夽

,

夽夽

Lucas

Pinto

D’Amico

Fam

a

_,

_Vagner

_Messias

_Fruheling

b

_,

_Barbara

_Pupim

b

_,

Carlos

Henrique

Ramos

c

_,

_Márcio

_Fernando

_Aparecido

_de

_Moura

d

_,

_Mário

_Namba

c,e

,

João

Luiz

Vieira

da

Silva

d

_,

_Luiz

_Antônio

_Munhoz

_da

_Cunha

f

_,

Ana

Paula

Gebert

de

Oliveira

Franco

g

_,

_Edmar

_Stieven

_Filho

h,∗

a_Studying_for_Specialist_title_in_Sports_Traumatology_at_Universidade_Federal_do_Paraná,_Curitiba,_PR,_Brazil

b_Resident_in_Orthopedics_and_Traumatology_at_Universidade_Federal_do_Paraná,_Curitiba,_PR,_Brazil

c_MSc_in_Surgery_from_Universidade_Federal_do_Paraná,_Curitiba,_PR,_Brazil

d_PhD_in_Orthopedics_and_Traumatology_from_Universidade_Federal_de_São_Paulo,_São_Paulo,_SP,_Brazil,_Professor_of_Human_Anatomy_at

UniversidadeFederaldoParaná,Curitiba,PR,Brazil

e_PhD_in_Surgery_from_Universidade_Federal_do_Paraná,_Curitiba,_PR,_Brazil

f_PhD_in_Orthopedics_and_Traumatology_from_Escola_Paulista_de_Medicina,_Universidade_Federal_de_São_Paulo,_Curitiba,_PR,_Brazil

g_PhD_in_Dentistry_from_Pontifícia_Universidade_Católica_do_Paraná,_Curitiba,_PR,_Brazil

h_Professor_of_Orthopedics_and_Traumatology_at_Universidade_Federal_do_Paraná,_Curitiba,_PR,_Brazil

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t

i

c

l

e

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n

f

o

Articlehistory:

Received8May2012 Accepted3July2012

Keywords:

Anatomy Cadaver Knee

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b

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Objective:Tostudytheanatomyoftheobliquepoplitealligament,asregardsitsdimensions, expansionandanatomicalrelationships.

Methods:Elevencadaverkneesweredissectedinordertostudytheanatomyandtake mea-surementsofanatomicalstructuresandrelationshipsoftheobliquepoplitealligament.The dissectionwasforposterioraccesstotheproperexposureoftheobliquepoplitealligament, thesemimembranosusmuscleanditsexpansions.Formeasurementofdimensions,40×12 needleswereusedformarkingthespecificpointsandacaliper.Theangleswerecalculated usingthesoftwareImageProPlus®_.

Results:Thedistancefromtheoriginoftheobliquepoplitealligamenttothetibialplateau was7.4mm,thethicknessatitsoriginwas7.3mm,lengthwas33.6mmandthetibialplateau angle34.8◦_._The_length_of_the_expansion_of_the_proximal_oblique_popliteal_ligament_was

39.2mm,thickness7.8mmandangleoftheobliquepoplitealligamentwithitsexpansion 32.2◦_.

Conclusion:Theobliquepoplitealligamentisthick,risesinthesemimembranosusand pro-trudesproximallyforminganacuteanglewiththejointinterline,crossingthepopliteal fossa.Insomecasesithasaproximalexpansion.

夽

Pleasecitethisarticleas:FamLPD,etal.Estudoanatômicodoligamentopoplíteooblíquo.RevBrasOrtop.2013;48:402–405.

夽夽

StudyconductedattheBiologicalSciencesSectorofUniversidadeFederaldoParaná,Curitiba,PR,Brazil.

∗ _{Corresponding}_author_at_:_Hospital_das_Clínicas,_Rua_General_Carneiro,_181,₆◦_andar,_CEP_80060-900,_Curitiba,_PR,_Brazil._Tel.:₊₅₅₄₁₃₃₁₅

1785;fax:+554133151785.

E-mail:[email protected](E.S.Filho).

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rev bras ortop.2013;48(5):402–405

403 Estudo

anatômico

do

ligamento

poplíteo

oblíquo

Palavras-chave:

Anatomia Cadáver Joelho

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e

s

u

m

o

Objetivo:Estudaraanatomiadoligamentopoplíteooblíquonoqueserefereàssuas dimen-sões,expansõeserelac¸õesanatômicas.

Métodos:Onzejoelhosdecadáveresforamdissecadoscomointuitodeseestudaraanatomia efazermediçõesdasestruturasedasrelaçõesanatômicasdoligamentopoplíteooblíquo.A dissecçãofoiporacessoposterioratéaexposiçãoadequadadoligamentopoplíteooblíquo, domúsculosemimembranosoedesuasexpansões.Paraaferiçãodasmedidas,foram usa-dosagulhas40×12namarcaçãodospontosespecíficoseumpaquímetro.Osângulosforam calculadoscomoauxíliodosoftwareImageProPlus®.

Resultados:Adistânciadaorigemdoligamentopoplíteooblíquoaoplatôtibialfoide7,4mm, aespessuranasuaorigemfoide7,3mm,ocomprimentofoide33,6mmeoângulocomo platôtibialfoide34,8◦_._O_comprimento_da_expansão_proximal_do_ligamento_poplíteo_oblíquo

foide39,2mm,aespessurafoide7,8mmeoângulodoligamentopoplíteooblíquocomsua expansãofoide32,2◦_.

Conclusão: Oligamentopoplíteooblíquoéespesso,nascenomúsculosemimembranoso, projeta-seproximalmente,formaumânguloagudocomainterlinhaarticularecruzaa fossapoplítea.Emalgunscasosapresentaumaexpansãoproximal.

Introduction

Theobliquepoplitealligament(OPL)isoneofthefive inser-tionsofthesemimembranosusmuscleandformspartofthe posterioranatomyoftheknee.1–3 _This_ligament_crosses_the

poplitealfossafrommedialtolateralandisconsideredtobe primarylimiterofgenurecurvatumandthusavoid hyperexten-sionoftheknee.4

Theposterioranatomyofthekneeconsistsofanetworkof structuresandhasuniquelycomplexbiomechanics. Control-lingkneehyperextensionduetosoft-tissuegenurecurvatumis oneofthefunctionsoftheposteriorstructures,especiallythe OPL.Hyperextensionmayaltergaitandmayleadtodifficulty inwalkingacrossunevenground.

Despitethegreatimportanceoftheposteriorstructuresof theknee,includingtheOPL,fewstudiesintheliteraturehave givenemphasistothesestructures,becausenotechniquesfor reconstructingthemhavebeendescribed.

Theaimofthisstudywastoexaminetheanatomyofthe OPLwithregardtoitsdimensions,expansionsandanatomical relationships.

Materials

and

methods

Thisstudy was conducted inthe Department ofAnatomy oftheBiologicalSciencesSectoroftheFederalUniversityof Paraná,inAprilandMay 2011.Elevenkneesfrom cadavers weredissectedwiththeaimsofstudyingtheiranatomyand makingmeasurementsonthestructuresandonthe anatom-icalrelationshipsoftheOPL.

Theinclusioncriteriaspecifiedthatonlykneesfrom cadav-erswithundamagedposteriorstructures,includingthejoint capsule,withoutpreviousarthrotomy,shouldbeused.Eleven kneesfulfilledthecriteria.Thedissectionwasperformedby

meansofposterioraccessandwasdonesuchthatsufficient exposureofthesemimembranosusmuscle,theOPLandtheir expansionswasobtained.Allthekneeswereconservedin10% formol.

To make the measurements, 40×12 needles and metal calipers(AeroSpace–150mm)wereusedtomarkoutspecific points.5_Measurements_were_made_of_the_distance_from_the

originoftheOPLtothetibialplateau(O-P),thethicknessofthe OPLatitsorigin(Th-O),thelengthoftheOPL(L),thethickness ofthesemimembranosusmuscledatthepointwheretheOPL arises(Th-S),thethicknessoftheOPLattheoriginofits prox-imalexpansion(Th-OPL-Exp),thethicknessoftheproximal expansionoftheOPL(Th-Exp)andthelengthoftheproximal expansionoftheOPL(L-Exp).

TheanglesoftheOPLwiththetibialplateau(A-P)andof theOPLwithitsexpansion(A-Exp)werecalculatedwiththe aidoftheImageProPlus®_software,_version_4.5_for_Windows

(MediaCybernetics,Inc.,USA)(Fig.1).

Results

Themeanandstandarddeviationresultsfromthe measure-mentsmadearepresentedinTable1.

Proximal expansionof the OPL, with a mean lengthof 39±7mm(L-Exp),wasobservedinfouroftheelevencases. Itwasfoundtobeabsentintheothersevenanatomical spec-imens(Fig.1).

Discussion

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rev bras ortop.2013;48(5):402–405

Table1–Meansandstandarddeviationsfortheanatomicalstructuresoftheobliquepoplitealligament.

O-P Th-O L A-P Th-S Th-OPL-Exp Th-Exp L-Exp A-Exp

Mean 7.4 7.4 33.6 34.8 11.4 5.2 7.8 39.2 32.2

Standarddeviation 2.0 2.0 4.8 8.0 2.0 2.5 3.3 7.2 6.6

O-P,distancefromtheoriginoftheOPLtothetibialplateau;Th-O,thicknessoftheOPLatitsorigin;L,lengthoftheOPL;A-P,angleoftheOPL withthetibialplateau;Th-S,thicknessofthesemimembranosusatthepointatwhichtheOPLarisesfromit;Th-OPL-Exp,thicknessoftheOPL attheoriginofitsproximalexpansion;Th-Exp,thicknessoftheproximalexpansionoftheOPL;L-Exp,lengthoftheproximalexpansionofthe OPL;A-Exp,angleoftheOPLwithitsexpansion;SD,standarddeviation.

Fig.1–Anatomyoftheobliquepoplitealligament.A-Exp, angleoftheOPLwithitsexpansion;A-P,angleoftheOPL withthetibialplateau;L,lengthoftheOPL;L-Exp,lengthof theproximalexpansionoftheOPL;Th-Exp,thicknessof theproximalexpansionoftheOPL;Th-OPL-Exp,thickness oftheOPLattheoriginofitsproximalexpansion;Th-O, thicknessoftheOPLatitsorigin;Th-S,thicknessofthe semimembranosusatthepointatwhichtheOPLarises fromit;O-P,distancefromtheoriginoftheOPLtothetibial plateau.

factthatnotechniqueforreconstructingthisstructurehas beendescribed.

TheOPListhemainstructureofthe so-calledposterior semimembranosuscomplexofthekneeandtheimportance ofthis structureisemphasizedbothbyits dimensionsand byitsbiomechanicalimportance.Inadescriptivelaboratory

study, dissections were performed on 20 fresh specimens andstructuresthatwouldpossiblylimithyperextensionwere sectioned.Independentoftheorderofthesectioningdone, aftersectioningtheOPLtherewasanincreasedin hyperex-tension of2.5degrees.Itwasconcludedthatthisstructure wasthemainlimiterofhyperextensionandsoft-tissuegenu recurvatum.4

In the present study, it was observedthat the OPL isa structure that originates together with the tendon of the semimembranosusmuscle,andthatitsinsertioninthe pos-teriorcapsuleofthekneeistogetherwiththelateralcondyle, thereby forminganangleof34.8◦ _with_the _medial_plateau,

withapathfromdistallymedialtoproximallylateral. Inadescriptiveanatomicalstudyontheposterior struc-turesofthekneebymeansofmagneticresonanceanalysis, a sixth branch of the semimembranosus muscle originat-ing together withthe OPLwas described.Thiswould have thefunctionofprotectingtheposteriorcornuofthe menis-cusagainsttraction.6_This_structure_was_not_observed_in_the

presentstudy,whichisconcordantwiththestudybyLaPrade etal.,7_who_observed_insertion_in_the_{meniscofemoral}_portion

oftheposterolateralcapsuleoftheknee.

Among the eleven specimens dissected in the present study,itwasobservedthatfourofthempresentedbifurcation oftheOPL,thusformingadoubleinsertion,whichisdescribed inthisstudyasdistalexpansionandproximalexpansion.In another anatomicalstudy,twolateral insertionsoftheOPL weredescribed:oneinthefabella(cartilaginousorbony),and theotherinthemeniscofemoralportionoftheposterior cap-sule.However,theprevalencesoftheseexpansionswerenot reported,i.e.whetherthisisthegeneralruleinallthe speci-mensorwhetherthisoccursinonlysomeofthem.7

Oneofthebiggestproblemsindiscussingastudyonthe OPListhatthereisnostandardregardinghowmeasurements shouldbemadeonthisstructure,orinrelationtothe nomen-clatureofitsexpansions.Thus,thereisalackofuniformity amongthedataintheliterature,andthecapacityfor compar-isonbetweenstudiesislost.Thedataonsomemeasurements obtainedinthepresentstudycanbecomparedwiththoseof thestudybyLaPradeetal.7

At its medialorigin, the OPL had a mean thickness of 7.4mm. On the other hand, LaPrade et al.7 _found _slightly

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rev bras ortop.2013;48(5):402–405

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distalexpansioninthepresent study.Thethicknessofthe proximal expansion was also divergent. A mean value of 7.8mmwasfoundinthepresentstudy,whileLaPradeetal.7

foundavalueof4.5mm.

Thethicknessofthesemimembranosusinitsportionfrom whichthetendonoftheOPLoriginatespresentedvery sim-ilar values. In the present study, this was 11.4mmand in thestudybyLaPradeetal.,7 ₁₂_mm._This_similarity_possibly

occurredbecause thismeasurementisextremelysimpleto makeandthereislittlemarginforvariationbetween examin-ers.

Conclusion

TheOPLisathickligamentthatarisesinthe semimembra-nosus,at7.4mmfromthetibialplateau,projectsproximally, formsanangle of34.4 degreeswiththejoint interlineand crossesthepoplitealfossa.Insomecases,itpresentsproximal expansion.

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

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