Rev. bras. ortop. vol.48 número5

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

Original

article

Posterior

cruciate

ligament

injury:

characteristics

and

associations

of

most

frequent

injuries

夽

,

夽夽

Marco

Túlio

Lopes

Caldas

,

Gilberto

Ferreira

Braga

,

Samuel

Lopes

Mendes

,

Juliano

Martins

da

Silveira

_,

_Robson

_Massi

_Kopke

a_{OrthopedistandTraumatologist;HeadoftheMedicalResidenceServiceofHospitalMariaAméliaLins,Fundac¸ãoHospitalardoEstado}

deMinasGerais(FHEMIG);MemberoftheKneeGroupofHospitalMariaAméliaLins,FHEMIG,BeloHorizonte,MG,Brazil

b_{PreceptorofMedicalResidenceinOrthopedicsandTraumatology,HospitalMariaAméliaLins,FHEMIG,BeloHorizonte,MG,Brazil}

c_{ResidentPhysician(R4)inKneeOrthopedicsatHospitalMariaAméliaLins,FHEMIG,BeloHorizonte,MG,Brazil}

d_{ResidentPhysician(R4)inKneeOrthopedicsattheOrtolifeClinic,BeloHorizonte,MG,Brazil}

a

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n

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o

Articlehistory:

Received1July2012 Accepted3September2012

Keywords:

Retrospectivestudies Knee

Posteriorcruciateligament/injuries Posteriorcruciateligament/surgery

a

b

s

t

r

a

c

t

Objective:ToinvestigatetheprevalenceandcombinationsofPCLinjuriesandtheir

correla-tionswiththemechanism,theoccurrenceofevidentdislocationandassociatedfracture.

Method:Aretrospectivestudyof85lesionsofPCLoperatedbetween2003and2010.Diagnosis

byphysicalexaminationanddynamicradiography,comparedwithsurgicalfindings.

Results:InjuriesinvolvingthePCLweremoreprevalentinmen(78.8%)withameanageof33

years.Themaincausewastrafficaccidents(73.80%),and(49.4%)motorcycle.IsolatedPCL injuryoccurredin(15.3%)cases,andcombined(84.7%).Amongtheisolatedlesions,bone avulsionswerenine(10.6%).ThemostassociatedPCLinjuriesweretheACL(48.2%), fol-lowedbyLCLPCL/PLC(22.4%).FracturesweremoreassociatedwithcombiningPCL+LCL/PLC injuriesanddidnotappearinthePCL+MCL/PMC.Complicationsbeyondfractures: periph-eralnerveinjury(4.8%)andvascular(1.2%).Evidentdislocationinprimarycare(16.7%)was moreprevalentincombinedACL+PCL+MCL/PMC(44.4%).Halfthepatientswereoperated duringtheacutephase.Therewasastatisticallysignificantdifference(p<0.05)comparing eachcombinationofligamentinjurieswiththepresenceoffracture,dislocationorclear mechanismofinjury.

Conclusion: SurgicaltreatmentofPCLinjuriesinacenterfororthopedictraumacarewas

mostlymultiligamentandmainlyinvolvingtheACL.Asignificantassociationwasseen betweenthetypeofinjurywithmechanismofinjury,presentationoftheknee,ifdislocated orreduced,andthepresenceofassociatedfracture.

©2013SociedadeBrasileiradeOrtopediaeTraumatologia.PublishedbyElsevierEditora Ltda.Allrightsreserved.

夽

Pleasecitethisarticleas:CaldasMTL, BragaGF, MendesSL,daSilveiraJM,Kopke RM.Lesõesdoligamentocruzadoposterior: característicaseassociac¸õesmaisfrequentes.RevBrasOrtop.2013;48:427–431.

夽夽

StudyconductedattheHospitalMariaAméliaLins,Fundac¸ãoHospitalardoEstadodeMinasGerais,BeloHorizonte,MG,Brazil.

∗ _{Correspondingauthorat:RuaFlavitaBretas,29/901,Luxemburgo,BeloHorizonte,CEP30380410MG,Brazil.}

E-mail:mtuliolc@gmail.com(M.T.L.Caldas).

Lesões

do

ligamento

cruzado

posterior:

características

e

associac¸ões

mais

frequentes

Palavras-chave:

Estudosretrospectivos Joelho

Ligamentocruzado posterior/lesões Ligamentocruzado posterior/cirurgia

r

e

s

u

m

o

Objetivo: Pesquisaraprevalênciadaslesõesdoligamentocruzadoposterior(LCP)esuas

combinac¸õesecorrelac¸õescomomecanismoeaocorrênciadeluxac¸ãoevidenteefratura associada.

Método: Estudo retrospectivo de 85 lesões do LCP operadas entre 2003 e 2010.

Diag-nósticopormeiodoexamefísicoedaradiografiadinâmica,confrontadoscomachados cirúrgicos.

Resultados: LesõesqueenvolveramoLCPforammaisprevalentesnoshomens(78,8%)com

médiadeidadede33anos.Acausaprincipalfoioacidentedetrânsito(73,80%),dosquais 49,4%demotocicleta.LesãoisoladadoLCPocorreuem15,3%doscasosecombinadaem 84,7%.Dentreaslesõesisoladas,noveforamavulsõesósseas(10,6%).Oligamentomais associadoàslesõesdoLCPfoiocruzadoanterior(48,2%),seguidodalesãocombinadado LCPcomoligamentocolaterallateral/cantopóstero-lateral(22,4%).Fraturasestiverammais associadasàcombinac¸ãoLCP+LCL/CPLenãoapareceramnaslesõesdoLCP+ligamento colateralmedial/cantopóstero-medial.Complicac¸õesalémdefraturas:lesãodenervo per-iférico(4,8%)evascular(1,2%).Luxac¸ãoevidentenoprimeiroatendimento(16,7%),mais prevalentenacombinac¸ãoLCP+LCA+LCM/CPM(44,4%).Metadedospacientesfoi oper-adanafaseaguda. Houvediferenc¸aestatísticasignificativa (p<0,05)nacomparac¸ãode cadacombinac¸ãodelesõesdeligamentoscomapresenc¸adefratura,luxac¸ãoevidenteou

mecanismodotrauma.

Conclusão: LesõesdoLCPsubmetidas atratamento cirúrgicoem centro deatenc¸ão ao

traumaortopédicoforamnasuamaioriamultiligamentareseenvolveramprincipalmenteo LCA.Houveassociac¸ãosignificativaentreotipodelesãocomomecanismodetrauma, a forma de apresentac¸ão do joelho, se luxado ou reduzido, e a presenc¸a de fratura associada.

©2013SociedadeBrasileiradeOrtopediaeTraumatologia.PublicadoporElsevier EditoraLtda.Todososdireitosreservados.

Introduction

Withtheexplosiveincreaseinthenumberofvehicles, espe-ciallymotorcycles,lower-limbinjuriesandparticularlyknee

injuries have become public health problems. They have

high social and economic costs. Improvements in

diagno-sis and advances in knowledge of anatomy, biomechanics

andsurgicaltechniqueshaveincreasedtheinterestin stud-iesinvolving theposterior cruciateligament (PCL).1–6 _Large

number ofPCLinjuriesare caused byhigh-energytrauma,

and in these cases, knee injury may be difficult

particu-larlywhenpatientspresentfracturesoftheipsilateralfemur and/or tibia. In evaluating these patients, just as in

mul-tiple trauma cases, ligament injuries may gounnoticed at

theinitialattendance.7,8_{Fewstudieshaveevaluateddifferent} combinationsofinjuriesthatinvolvethePCL,inrelationto themechanism,incidenceoffracturesinthekneeaffected or evident dislocation. Studying these characteristics may

contribute toward making a correct diagnosis during the

acutephaseandenablingappropriatetreatmentattheideal time.

Theobjective ofthisstudy wastoinvestigatethe preva-lenceofcombinedinjuriesofthePCLandtheircorrelations withthemechanism,occurrencesofevidentdislocationand associatedfractures.

Materials

and

methods

Byconsultingourinstitution’ssurgicalrecords,wesurveyed the medicalfilesofpatientswho underwentsurgical

treat-ment for PCL injuriesof the knee between May 2003 and

September2010andfound85casesin84patients.We

inves-tigated the trauma mechanism, the number of ligaments

injured,theprevalenceofdifferentcombinationsofinjuries

and the association of each of them with knee fractures,

evident dislocation, trauma mechanism and time elapsed

betweentheaccidentandthedefinitivetreatment.Inthe

insti-tutionwherethestudywasconducted,thediagnosesmade

inthe emergencysectorwascomparedwiththe diagnoses

thatresidentsundergoingspecializationtraining withinthe

KneeSurgeryGroupmadebymeansofhistory-taking,

phys-icalexaminationandradiographs.Afterwards,thediagnoses

were reviewed by knee surgeons, who made physical and

radiologicalexaminationsofstress(dynamicexaminations), underanesthesiaduringtheimmediatepreoperativeperiod.

The diagnosis was complemented bythe surgical findings

fromthecasesoperatedduringtheacutephase.

Descriptive analysis was performed on the study

Table1–Frequenciesofinjuredligamentsandtrauma mechanism.

Frequency Percentage

Numberofligamentsinjured

1 12 14.1

2 37 43.5

3 35 41.2

4 1 1.2

Traumamechanism

Motorcycle 42 49.4 Beingrunover 17 20.0

Sprain 12 14.1

Carcollision 8 9.4 Fallfromheightormartialarts 3 3.5

Table2–Frequencyofassociatedinjuries,evident dislocationandPCLboneavulsion.

Frequency Percentage

Fracturea _{17 20.5}

Peripheralnerveinjuryb _{4 4.8}

Vascularinjuryb _{1 1.2}

Evidentdislocationb _{14 16.7}

PCLboneavulsion 9 10.6

a _{Twocaseswithoutinformation(2.4%).}

b _{Onecasewithoutinformation(1.2%).}

Pearson’schi-squaretestwasalsoused,inordertocompare proportions, and Fisher’s exact test for small samples. For

numericalvariables,thenonparametricMann–Whitneytest

ortheKruskal–Wallistestwasused,becauseofthe asymmet-ricalnatureofthevariablestested.Thesignificancelevelwas takentobe5%.TheSPSS15.0softwarewasused.

Results

TheincidenceofPCL injurieswas greater amongthe men

(78.8%).Themeanagewas32.9years,withastandard devia-tionof11.9.Mostofthecasespresentedtwo(43.5%)orthree (41.2%)injuredligaments.TheprevalenceofPCLinjuryalone

was 15.3%. Nine (10.6%) of the injuries were due to bone

avulsion.Trafficaccidentswereresponsiblefor73.8%ofthe injuriesandofthese,themostfrequenttraumamechanism (49.4%)wasmotorcycleaccidents,followedbybeingrunover (20%)(Table1).

Table2showsthefrequenciesofassociatedinjuries, evi-dentdislocationandPCLavulsion.

PCLinjuriescombinedwithotherligamentsaccountedfor 84.7%ofthecases,andofthese,thelargestnumberinvolved

the anterior cruciate ligament (ACL) (48.2%), followed by

thelateralcollateralligament/posterolateralcorner(LCL/PLC) (22.4%).Theprevalenceofinjuriestobothcruciateligaments withoutcombinationwithperipheralligamentsorwith evi-dentdislocationwas 7.1%.Inanalyzing therelationship of eachinjurycombinationwiththecause,motorcycleaccidents werethemostfrequentcause,withastatisticallysignificant difference(p-value<0.05),exceptforpatientswiththe com-bination of PCL+medial collateral ligament/posteromedial

corner (MCL/PMC), forwhombeing runover was themost

frequentmechanism(41.7%)(Table3).

There was a significant difference (p<0.012) in

compar-ing the different combinations of ligament injuries with

occurrences of fractures or presentation of evident dislo-cation at the emergency service (p<0.007). Fractures were moreassociatedwiththecombinationsPCL+LCL/PLC(38.9%) andPCL/ACL+LCL/PLC(37.5%),whileevidentdislocationwas

more associatedwith the combination PCL/ACL+MCL/PMC

(44.4%)(Table4).

In 85% of the cases, the knee ligaments were operated

withinthe firsteightmonths,and 50%oftheseoperations wereperformedintheacutephase,uptothreeweeksafter theinjury.

Discussion

Inthisstudy,85PCLinjurieswereevaluated,inpatientswho

underwentsurgicaltreatmentinanorthopedictraumacare

center betweenMay2003and December2010. The

diagno-siswasdonebymeansofclinicalexamination,withdynamic

assessmentofthekneeunderanesthesia,andwas

comple-mentedbythesurgicalfindingsinthecasesoperatedinthe acutephase.Withregardtogender,therelationshipconsisted ofapproximatelyfourmenforeverywoman,andthegreatest incidencewasinthethirddecadeoflife,i.e.similartoreports intheliterature.9,10

Fanellietal.11,12_{reportedthattheincidenceofPCLinjury} was44%inatertiary-leveltraumacarecenter,amongknees

withhemarthrosisthatunderwentexaminationunder

anes-thesiaand arthroscopy.Themaincauseswere high-energy

trauma (81.5%) and sports injuries (18%). PCLinjury alone

occurred in 7.5% and combinations with other ligament

injuriesin92.5%.LaPrade13_{assessedkneeligamentinjuries} andobservedthatPCLruptureoccurredin14.4%ofthecases,

and in8.2% ofthe patients withhemarthrosis after acute

trauma.

Acute-phase knee ligament injuries are diagnosed by

meansoftakingadetailedhistory,makingacarefulphysical

examinationandproducing stressradiographsunder

anes-thesia.Magneticresonanceimagingisconsideredtobethe goldstandard.13–17_{Insomecases,theligamentinjuryisnot}

diagnosedbecausethesymptomsmayremainmaskedwhen,

forexample,ipsilateralfracturesoccur,asreportedbyBraga et al.18_{Intheir study,28 patientswith29unstablefemoral}

fractures were treated with locking intramedullary nails

and were evaluated inthe immediatepostoperativeperiod

with the aim of determining the incidence of associated

ligamentinjuries.Eightpatients(28.6%)presentednineknee ligament injuries(32.1%; onebilateral case).None ofthese injurieshadbeenreportedattheemergencyservice.Inthe same study,therewasastatisticallysignificant association betweencomplexkneeinjuryandbeingrunover(p=0.004).

These authors emphasizedthat theknees ofpatientswith

ipsilateral femoral fractures caused by high-impact injury shouldberoutinelyexamined.

Table3–Typesofinjurycombinationsversusoccurrencesoffracturesorevidentdislocation.

PCLalone PCL+LCL/PLC PCL+MCL/PMC PCL/ACL+LCL/PLC PCL/ACL+MCL/PMC p-Value

Fracture

2 7 0 6 1 0.012a

16.7% 38.9% 0% 37.5% 5.6%

Evidentdislocation

0 3 0 3 8 0.007b

0% 16.7% 0% 18.8% 44.4%

a _{Pearson’schi-squaretest.}

b _{Fisher’stest.}

from 70% for grade I injuries to 97% for grades II and

III.19_{Resultsfromclinicalexaminationsanddynamic}

radio-graphsshouldbecomparedwithmagneticresonanceimaging

(MRI).20_{Unfortunately,fewhospitalswithintheBrazilian} set-tingprovideaccesstoMRIintheemergencysector.Thus,itis importanttohavestudiesthatanalyzetheresultsfrom assess-mentsonacuteligamentinjuriesbasedondynamicphysical andradiologicalexaminationunderanesthesia.

Inthepresentseries,itwasfoundthat78.8%oftheinjuries were from trafficaccidents, ofwhich 49.4% were motorcy-cleaccidents.Theseresultswere closetothose ofFanelli,1 whofoundthat81.5%oftheircasesresultedfromhigh-energy trauma.Schulzetal.9_{studied494patientsandreportedthat} thecommonestcausesweretrafficaccidents(45%)andsports injuries(40%),andthatmotorcycleaccidents(28%)andsoccer injuries(25%)werethecommonestspecificcauses.

Identifyingdifferenttypesofkneeligamentinjuryis impor-tant forthe prognosis and fordefining the treatment. PCL injuryalonehaslowincidence(7.5%)andthoseofgradesIand IIhavegreaterchanceofhealing,inthesamewayasmedial collateralligament(MCL)injuries.20,21_{PCLinjuriesalonemay} beasymptomatic,asreportedbyParolieandBergfeld,21_who foundthattheincidenceofthischaracteristicwas2%among playersintheAmericanNationalFootballLeague(NFL).Inour series,wefoundthattheincidenceofPCLinjuriesalonewas 15.3%andthat69.2%ofthemwereduetoboneavulsion.All ofthesecasesunderwentsurgicaltreatment.

Thereiscontroversyregardingthebesttreatmentforgrade III PCL injuries that occur in isolation and for those that arecombinedwithmedialorperipheralligaments.3–5_Inthe

presentseries,surgicaltreatmentwasindicatedforcomplete PCLinjury(gradeIII)orforcombinedinjurywhenthe poste-riordisplacementofthetibiawas>10mm.8,19_{Inconcordance} withareportintheliterature,5_{surgerywasthetreatment} indi-catedforinjuriesthatinvolvedthePCLorPCL/ACLcombined withlateralstructures.Hammoudetal.22_{conductedareview} study on21caseseriesofPCLinjuryalone and10of

com-bined injuries.They concludedthattherewas noevidence

regardingthebest treatmentorthebestsurgicaltechnique tochoose, andthat despitethereportsofgood results fol-lowingPCLreconstruction,evaluationswithlongerfollow-up suggestedthatinmostcases,normalkneestabilitywasnot restored.

Our series included onlythe casesthat underwent

sur-gical treatment inwhich the main injury mechanism was

high-energytrauma.Thischaracteristicmayexplainthehigh numberofcasesinvolvingtwoormoreligaments(85.9%ofthe cases).Inconcordancewithotherstudies,PCLinjuryappeared ingreatestnumberinvolvingtheACL,i.e.asinjuriesofboth cruciateligaments,orincombinationwithmedialorlateral peripheralligaments.10,19

Therewasastatisticallysignificantdifferencein compar-ingthecombinationsofligamentinjurieswiththeprevalence offracturesorevidentdislocation.Associationswithfractures

were morecommonincombinations betweenthe PCLand

lateral peripheral ligaments.Evident dislocationwas more

associated with the combination of PCL/ACL with lateral

peripheralligamentsanddidnotoccurincasesofPCLinjury aloneorincombinationsbetweenthePCLandmedial periph-eralligaments.Theprevalenceoffracturesorboneavulsions

Table4–Comparisonoftypesofinjurycombinationsversusmechanism.

PCLalone PCL+LCL/PLC PCL+MCL/PMC PCL/ACL+LCL/PLC PCL/ACL+MCL/PMC p-Value

Traumamechanism 0.022a

Beingrunover 0 2 5 3 6

0% 11.8% 41.7% 18.8% 35.3%

Car 2 1 0 2 2

15.4% 5.9% 0% 12.5% 11.8%

Sprain 0 2 2 5 1

0% 11.8% 16.7% 31.3% 5.9%

Motorcycle 11 12 3 6 7

84.6% 70.6% 25.0% 37.5% 41.2%

Others 0 0 2 0 1

0% 0% 16.7% 0% 5.9%

was20.5%.Injurytobothcruciateligaments(ACL/PCL)without combinationwithmedialorlateralperipheralligamentsand withoutassociationwithevidentdislocationappearedin7.1% ofthecases.Thiswasmuchlowerthanwhatwasreportedby Lustigetal.23_{whofoundthiscombinationin25%ofthecases} inamulticenterstudybytheFrenchSocietyofOrthopedics andTraumatology.Itwasobservedthattheseauthorsdivided thecomplexmulti-ligamentinjuriesintothoseaffectingboth cruciateligaments(25.4%)andthosewithclassicaltraumatic dislocation(74.6%).Theyusedepidemiologicalcriteriasuchas age,presenceofassociatedinjuriesandtypeofinjuryinorder toindicateornotindicatesurgicaltreatment.Theychoseto reconstructthePCLduringtheacutephase,inpatientsunder theage of60 years withoutassociatedvascular injuriesor exposeddislocation,whentheposteriordrawerwasgreater than10mmand/orthefrontal,medialorlateralopeningwas greaterthan15mm.TheydidnotindicateACLreconstruction intheacutephase.

Inthe series evaluatedin ourstudy, onlyonecasewas referredwithareportofpoplitealarteryinjury. Itwas also seenthattherewaslowprevalence(4.8%)ofcommonfibular nerveinjury,comparedwithotherstudies.6,24

In 85% ofthe cases, the patients were operated within eightmonths,and50%ofthesewereoperatedwithinthefirst threeweeks,i.e.duringtheacutephase.Thegreatestmedian timebetweentheinjuryandthesurgery(105days)occurred amongpatientswithPCL+LCL/PLCinjuriesandthesmallest time(8.5days)amongthosewithPCLinjuryaloneduetobone avulsion.SevereinjuriessuchasthoseofthePCL+LCL/PLC wereoperatedlateroninsomecases,whichiscontrary to the idealmanagement ofgiving priorityto earliersurgical treatmentforthiscombinationofinjuries.Intheinstitution

wherethe study was conducted, multipletrauma patients

whohaveundergonedamagecontrolareoftenreceived,and this also often postpones the definitive treatment for the ligamentinjury. Inseriessuchasthat ofSchulz etal.9 _the knee specialistsonlyreceived 10.3%of thepatients within thefirst30daysaftertheinjury.Surgerywasperformedafter ameantimeperiodof44.4months.

Thecriterionofonlyincluding patientswho underwent surgicaltreatmentinvolvingthePCLwasanattempttocreate

agroupthatwouldbemorehomogenousintermsofcause

andeffect. However,inastudy on kneedislocation, Buiet al.20_{foundthattraumathatwasconsideredtobelow-energy} wasthemechanismin15cases(75%),suchasamateursports orsimplefalls,andthatonly20%were duetohigh-energy trauma,suchascaraccidents.

The number of 85 cases studied seems to have been

statisticallyadequate,giventhe relatively low incidenceof PCLinjuriesinthegeneralpopulation.Inthedataanalysis, consideringthelargenumberofcombinedinjuries,somewith very low prevalence, statistical analysis for small samples

wasused.

Conclusion

ThePCLinjuriesthatunderwent surgicaltreatmentinthis orthopedictraumacenterweremostlyaccompaniedby multi-ligamentinjuries.Themostprevalenttraumamechanismwas

trafficaccidents,notablywithinvolvementofmotorcyclesand

affectingmaleindividuals.TheACLwastheligamentmost

frequently injuredinassociation withthePCL, followedby lateralperipheralinjury.Therewasasignificantassociation

betweenthetypeofinjuryandthetraumamechanism,form

ofkneepresentation(dislocatedorreduced)andpresenceof associatedfractures.

Conflicts

of

interest

Theauthorsdeclarethattherewerenoconflictsofinterest.

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