Rev. bras. ortop. vol.48 número5

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

Original

Article

Amputation

after

failure

or

complication

of

total

knee

arthroplasty:

prevalence,

etiology

and

functional

outcomes

夽

,

夽夽

Alan

de

Paula

Mozella

a,∗

,

Idemar

Monteiro

da

Palma

a

,

Alberto

Ferreira

de

Souza

b

,

Guilherme

Ornellas

Gouget

b

_,

_Hugo

_Alexandre

_de

_Araújo

_Barros

_Cobra

c

a_Orthopedist_at_the_Knee_Surgery_Center,_Instituto_Nacional_de_{Traumatologia}_e_Ortopedia,_Rio_de_Janeiro,_RJ,_Brazil

b_Resident_Physician_(R3)_in_Orthopedics_and_Traumatology_at_Instituto_Nacional_de_{Traumatologia}_e_Ortopedia,_Rio_de_Janeiro,_RJ,_Brazil

c_Orthopedist_and_Head_of_the_Knee_Surgery_Center,_Instituto_Nacional_de_{Traumatologia}_e_Ortopedia,_Rio_de_Janeiro,_RJ,_Brazil

a

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t

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c

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Articlehistory: Received21May2012 Accepted3July2012

Keywords:

Postoperativecomplications Amputation

Arthroplastykneereplacement

a

b

s

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c

t

Objective:Identify theetiologyand incidence,as welltoassess functionaloutcomesof patients,undergoinglower limbamputationafterfailureor complication oftotalknee arthroplasty.ThesepatientsweretreatedattheCenterforKneeSurgeryattheNational InstituteofTraumatologyandOrthopedics(INTO),during theperiod ofJanuary2001to December2010.

Methods:Thepatientswereinterviewedandtheirchartswereretrospectivelyanalyzedto evaluatetheirfunctionaloutcome.

Results:Theincidenceofamputationduetofailureorcomplicationoftotalknee arthro-plastywas0.41%in2409cases.Recurrentdeepinfectionwasthecauseofamputationin81% ofcases,beingStaphylococcusaureusandPseudomonasaeruginosathemostfrequentgerms. Vascularcomplicationsandperiprostheticfractureassociatedtometaphysealboneloss werealsocausesofamputation.Inourstudy,44%ofamputeespatientswereusingorthesis and62.5%havehadtheabilitytowalk.

Conclusion:Incidenceof0.41%,beingthemaincauserecurrentinfection.Thefunctional outcomeislimited,andthefittingachievedin44%ofpatientsandonly62.5%areambulatory. ©2013SociedadeBrasileiradeOrtopediaeTraumatologia.PublishedbyElsevierEditora Ltda.Allrightsreserved.

夽

Pleasecitethisarticleas:dePaulaMozellaA,daPalmaIM,deSouzaAF,GougetGO,deAraújoBarrosCobraHA.Amputac¸ãoapósfalha oucomplicac¸ãodeartroplastiatotaldejoelho:incidência,etiologiaeresultadosfuncionais.RevBrasOrtop.2013;48:406–411.

夽夽

StudyconductedattheKneeSurgeryCenter,InstitutoNacionaldeTraumatologiaeOrtopedia,RiodeJaneiro,RJ,Brazil.

∗ _{Corresponding}_author_at:_Praia_do_Flamengo,_66,_Bloco_B,_Sala_1313,_Rio_de_Janeiro,_RJ,_Brazil._CEP_22210-030.

E-mail:apmozella@terra.com.br(A.d.P.Mozella).

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Amputac¸ão

após

falha

ou

complicac¸ão

de

artroplastia

total

de

joelho:

incidência,

etiologia

e

resultados

funcionais

Palavras-chave:

Complicac¸õespós-operatórias Amputac¸ão

Artroplastiadojoelho

r

e

s

u

m

o

Objetivo: Identificar aetiologia e aincidência da amputac¸ãodomembroinferiorapós falhaoucomplicac¸ãodaartroplastiatotaldejoelhoeavaliarosresultadosfuncionaisdos pacientestratadospeloCentrodeCirurgiadeJoelhodoInstitutoNacionaldeTraumatologia eOrtopedia(Into)entrejaneirode2001edezembrode2010.

Métodos: Osprontuários foramretrospectivamente analisadosparacoletados dadose entrevistaparaavaliac¸ãodoresultadofuncional.

Resultados: A incidênciade amputaçãoem decorrência de falhaou complicaçãoapós 2.409artroplastiastotaisdejoelhofoide0.41%.Infecçãoprofundarecorrentefoicausade amputaçãoem81%doscasos.OsgermesmaisfrequentesforamStaphylococcusaureuse Pseu-domonasaeruginosa.Complicaçõesvascularesefraturaperiprotéticaassociadaaperdaóssea metafisáriarepresentaramindicaçãoemmenornúmerodecasos.Emnossoestudo,44% dospacientesamputadosapresentam–seprotetizadose62.5%apresentavamcapacidade dedeambulação.

Conclusões: Incidênciade 0.41%eprincipalcausainfecçãorecorrente.Oresultado fun-cionalélimitado,aprotetizaçãofoialcançadaem44%dospacientesesomente62.5%são deambuladores.

Introduction

Theconceptofimprovingjointfunctionthroughmodification ofitssurfacewasproposed byVerneuil1 _in_1860,_by_means ofinterpositionofsofttissuesforjointreconstruction.Inthis procedure,despitepainreductionandincreasedmobility,the jointstability achievedwas unsatisfactoryand gaverise to impairedfunctionalresults.

Today, total knee arthroplasty (TKA) is an effective

option, with a high success rate in treating cases of

advanceddestructionofthisjointcausedbyprimaryor sec-ondary osteoarthrosis. It provides considerable pain relief,

correction of deformities and improvement of limb

func-tion, and consequently better quality of life for these

patients.2,3

In medium and long-term clinical evaluations, several

authorshavedemonstratedgoodorexcellentresultsinmore than90%oftheirpatientswhoreceivedkneeprostheses.4–6_In otherstudies,thedegreeofsatisfactionreportedbypatients hasbeenanalyzed,andthesereportshavecorroboratedthe satisfactorydata,withgoodorexcellentresultsinaround90% ofthepatients.7–9

Inseveralcentersaroundtheworld,thedurabilityofthese

implants withmaintenanceofjointadequate function has

beenshowntobegreaterthan92%,13–15yearsaftertheinitial surgery.8–12

Because of the satisfactory results, the increased life

expectancyamongthe populationandthebetterqualityof

lifethat issought, the numbers ofTKA procedures is cur-rentlyincreasing.In2002,intheUnitedStates,therewasa 5%increaseinthenumberofTKAsperformedinrelationto thepreviousyears.13_Kurtz_et_al.14_estimated_that_by_the_year

2030,thenumberofprimaryTKAprocedures performedin

thatcountrywouldincreaseby670%.

Insomecases,afterseveralyearsofdurabilityand ade-quatefunctioning,arthroplastymaypresentfailure.Insuch cases,revisionsurgerybecomesnecessary,and satisfactory clinicalresultsareoftenobtained.15,16_In_other_cases, arthro-plastymaypresentfailureorcomplicationsthataredifficult todealwith.

Recurrentinfectionatprosthesissites,cutaneousor vas-cular complications and significant loss ofbone stock are challenging problems that are difficult tosolve and which sometimes haveunsatisfactory results.In thesesituations,

arthrodesis and resection arthroplasty are management

optionsforlimbsalvage.However,insomecases,the

treat-ment may be unsuccessful and these patients become

candidatesforlimbamputation.

Materials

and

methods

The aims of this study were to identify the etiology and

incidenceoflower-limbamputationafterfailureofor com-plicationsfrom TKA,and toevaluatethe functionalresults

among patients treatedat the KneeSurgery Center of the

National Institute ofTraumatology and Orthopedics(INTO)

betweenJanuary2001andDecember2010.

Thisstudywassubmittedforevaluationandapprovalby theResearchEthicsCommitteeofINTOandwasconductedat theKneeSurgeryCenterofthisinstitution.

Thepatients includedinthis study underwent

amputa-tion ofall or partofalower limbconsequent tofailure or complicationsafterconventionalprimaryTKA.Patientswho underwentamputationduetofailureoforcomplicationsfrom surgicalproceduresotherthankneeprosthesisimplantation wereexcluded.

The medical files were retrospectively analyzed in

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arthroplasty, datewhenarthroplasty was performed,

dura-bility of the implant, surgical risk (ASA), postoperative

complications,TKAfailuremechanism,number of

reopera-tionsandtreatmentsforcomplicationsandtheamputation level.

The total number ofknee arthroplasty procedures

per-formedovertheperiodwasobtainedfromthecomputerized recordsofINTO.

Toevaluatethefunctionalresults,thepatientswere inter-viewedandwereaskedwhethertheywereusingaprosthesis,

whether theywere capableofwalking,what distancethey

were abletowalk andwhether someformofsupportwas

neededforwalking.

Results

Between January 2001 and December 2010, 2409 TKA

pro-cedures were performed. Among these cases, 10 patients

underwentamputationduetofailureorcomplications relat-ingtotheprosthesis,andthustheincidencepresentedwas 0.41%.

Overthecourseofthisperiod,atotalof16amputations

were performed atINTO asa consequenceoffailure ofor

complications from TKA. However,some of thesepatients

wereexcludedfromtheincidencecalculation,giventhatfour

amputationswereperformedonpatientswhohadundergone

primaryTKAatotherservicesandtwocaseshadreceivedthe primaryprosthesisbeforethestudyperiodstarted(Fig.1).

Amputation wasperformed on eightmale patients and

eightfemalepatients.Thepatients’meanageatthetimeof thisprocedurewas67.1years,witharangefrom53to80years. In11cases,therightkneewasoperatedandinfivecases,the

Fig.1–PatientamputatedduetoinfectionafterTKA.

leftknee.Primarygonarthrosiswastheindicationfora pros-thesisintenofthesepatients(62.5%),rheumatoidarthritisin three(18.75%)andpost-traumaticarthrosisinthree(18.75%). Inthisseries,intwocasestheamputationwasperformed

onpatientswhohadundergonerevisionofprimarysurgery

andpresentedimplantswithamajordegreeofconstriction ofnails.In14patients,thecomplicationsorfailuresoccurred beforeexchangingtheprostheticcomponents.In10patients,

arthrodesiswas performedas alimbsalvage measure, but

withunsatisfactoryresults.

Themeantimethatelapsedbetweentheprimary arthro-plastyandtheamputationwasapproximately4.5years,with arangefromonedayto12years.Themeanlengthof follow-upaftertheamputationwas6.7years,witharangefromtwo tonineyears.

Inaccordancewiththeanestheticriskcriteriaofthe Amer-icanSocietyofAnesthesiology(ASA),87.5%wereclassifiedas ASAIIand6.25%asASAIII,while6.25%didnotpresentany clinicalcomorbidities(ASAI).

Recurrentdeepinfection wasidentifiedasthemain

eti-ology for amputation following TKA. This occurred in 13

cases, which represented 81% of the sample. Acute

arte-rial occlusionwasidentifiedasthe causeofamputationin twocases(12.5%)andperiprostheticfractureassociatedwith metaphyseal bone loss (type III inthe classificationof the

Anderson OrthopedicResearch Institute, AORI)occurred in

onecase(6.5%).Theinfectionwasdiagnosedafter osteosyn-thesis(Table1).

Extensiveskinnecrosiswasobservedintwocases. How-ever, inboth ofthem this complication occurred after the

infectiousconditionhadbeenproven.Amyocutaneousflap

wasneededinthecasesofbothpatients.

Inthepatientswhounderwentamputationdueto recur-rent infection,culturespresentedgrowth ofmorethanone bacterialagentin38%ofthecases.

ThemostprevalentgermwasStaphylococcusaureus,which wasidentifiedin54%ofthecultures.Methicillin-resistantS. aureuswasisolatedin31%.Methicillin-sensitiveS.aureus pre-sentedgrowthin23%ofthepatients.Pseudomonasaeruginosa wasidentifiedin38%oftheculturesandin31%itwas asso-ciatedwithanotherbacterialspecies.Acinetobacterbaumanii andKlebsiellapneumoniaewereidentifiedintwocases(15%), butwerenotverifiedasasingleagent.Serratiamarsenswas notedintwopatients(15%)andinoneasasingleinfectious agent.Proteusmirabiliswasnotedinonecaseofpolymicrobial infection(7.5%).

Themeannumberofsurgicalprocedurespriorto

ampu-tation was 6.8. When only the patients who underwent

amputationduetoinfectionwere takenintoconsideration, thenumberofpreviousproceduresrangedfrom3to22,with ameanof7.6.

Allofthepatientsunderwenttransfemoralamputation.In onecase,whichwasofvascularetiology,anamputationat tar-sometatarsaljointlevelwasinitiallyperformed,butbecause offailureinattemptstoperformthromboembolectomy,itwas necessarytoraisetheleveloftheamputation.Intwocases,it wasnecessarytoreviseandraisetheboneresectionbecause ofaninfectiousconditionintheamputationstump.

Over the course of the functional evaluations, three

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Table1–AmputationsduetofailureoforcomplicationsfromTKA.

Age Sex Diagnosis ASA Cause Duration No.ofprocedures Bacteria

1 62 F OA II Infection 2years 8 MRSA

2 64 F RA II Infection 10years 3 Pseudomonasaeruginosa+Proteus

mirabillis

3 69 F OA II Infection 9years 6 MSSA+Klebsiellapneumoniae

4 42 M RA II Infection 11years 6 Pseudomonasaeruginosa+Serratia

marsens

5 61 M TRAUMA II Infection 6years 8 Serratiamarsens

6 65 M TRAUMA II Infection 3years 4 MRSA

7 80 F OA III Infection 0 5 MSSA

8 66 F OA II Infection 2years 6 P.aeruginosa+K.

pneumoniae+Acinetobacterbaumanii

9 68 M OA I Infection 0 11 MRSA

10 62 F OA II Vascular 0 2

11 75 M OA II Fracture 1year 7

12 66 M OA II Vascular 0 0

13 62 F OA II Infection 12years 7 MSSA

14 51 M TRAUMA II Infection 4years 8 MRSA

15 62 M OA II Infection 1year 22 P.aeruginosa

16 51 F RA II Infection 7years 5 P.aeruginosa+A.baumanii

F,female;M,male;OA,osteoarthrosis;RA,rheumatoidarthritis;MRSA,methicillin-resistantStaphylococcusaureus.

datawereobtainedfromthelastfollow-upconsultation ana-lyzed.

Amongthe16patientswhounderwentamputation,only sevenwerefittedwithprostheses(44%).Allofthese individ-ualsweresaidtobeabletowalk,althoughwiththeexception ofonepatient, all ofthem requiredaids suchas apair of crutchesorawalkingframe.Twopatientswhohadbeenfitted withprosthesessaidthattheircapacitytowalkwaslimitedto theirhomes,whiletheotherfivesaidthattheywerecapable ofwalkingfordistancesgreaterthanablock(Table2).

Amongtheninepatientswhowerenotfittedwith

pros-theses (56%), six were incapable ofwalking and remained

restrictedtoawheelchair.Onepatientsaidthathewasableto walkaroundhishomewithhelp.Anothertwopatientswere capableofwalkingwithhelpfordistancesgreaterthanablock. Wedidnotidentify anystatistical relationship between age,thediagnosisthatcausedthefailureandmotivatedthe arthroplasty,andthefunctionalresultsfromfittingthe pros-thesisorfromwalking.

Discussion

Many differentstudies intheliteraturehavedealtwiththe maincomplicationthatcanoccurafterTKA.However,there arefewdataontheincidenceofamputationsduetofailures oforcomplicationsfromkneeprostheses.Outofmorethan 9000kneeprostheses assessed,Randet al.16_described _two cases(0.02%)ofinfrapatellaramputationrelatedtovascular insufficiency.

After performing 12,118 TKAs, Bengstonand Knutson17

studied357patientswhoevolvedwithdeepinfection.Inthis

sample,23patientshadtoundertransfemoralamputation.

Thus,theincidencefoundwas0.18%outofallthecasesand 6%whenonlytheinfectedarthroplastycasesweretakeninto consideration.Isiklaretal.10_reported_an_incidence_of_0.18%, i.e.nineamputationsafter5045arthroplastyprocedures per-formed.InthestudybySierraetal.15_on₂₅_patients,_the_cause oftheamputationwasrelatedtoprostheticreplacementof theknee,whichcorrespondedtoaprevalenceof0.14%.

Table2–Functionalresult.

Prosthesisuse Walking Aid Distance

1 No No:limitedtowheelchair

4 Yes Yes 2crutches >1block

9 Yes Yes No >1block

10 Yes Yes 2crutches Athome

13 Yes Yes Walkingframe Athome

14 No Yes 2crutches >1block

15 No Yes Walkingframe Athome

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Inourseries,theincidencewas0.41%,i.e.10amputations after2409arthroplastyprocedures.However,wehaddifficulty inidentifyingamputationsamongourpatientsthattookplace atotherhealthcareunits,eitherasacomplicationfromTKA orduetounrelatedcauses.

InthestudybyIsiklaretal.,10_deep_infection_was_identified insevenoftheeightcasesofamputation.Datapresentedby Sierraetal.15_identified_infection_as_the_main_cause_of amputa-tionafterTKA,whichoccurredin74%ofthepatients.Infection wasthemaincauseofamputationidentifiedinourseriesand occurredin81%ofthecases.

S.aureushasbeen thegerm mostfrequentlyisolated in postoperativeinfectionsinseveralinternationalcenters.18_In eightcasesofamputationduetoinfection,Isiklaretal.10 iden-tifiedS.aureusinthreepatientsandS.epidermitisinfour.Our samplewasconcordantwiththereportsintheliterature:S. aureuswasisolatedin54%oftheculturesfrompatients ampu-tatedduetoinfection.

Cutaneouscomplicationssuchasextensivenecrosismay evolve withdeepinfection after TKAin uptoa quarterof thepatients,asreportedindifferentstudies.10,15_In_our_study, outofthe16patientswhounderwentamputation,twocases presentedcutaneousnecrosisafterdeepinfectionhadbeen diagnosed.

Vascular complications after knee arthroplasty are rare eventsandgenerallyhavecatastrophicresults.Smithetal.19 notedthattheprevalenceofcomplicationsduetovascular

causes wasbetween 0.03%and 0.17%.These usuallyoccur

inpatientswithpreviouslyundiagnosedatherosclerotic dis-easeand,amongthesecases,25–43%evolvewithamputation.

Inoursample,twopatientsneededamputationbecauseof

ischemiaofthelimbshortlyafteranarthroplastyprocedure. Periprostheticfracturing associatedwith bone loss that

compromisedthe metaphyseal bone(type III ofAORI

clas-sification) was identified as the initial event that led to

amputationin6.5%ofoursample(onecase).Weemphasize

thatinfectionofthesurgicalsitedevelopedaftertreatingthe fracture.InthestudybySierraetal.,15_this_cause_represented thelowestprevalenceofoccurrencesofamputationafterTKA. Thepatientsunderwentanaverageof6.8proceduresprior toamputation.Takingonlythecasesofinfection into

con-sideration, this mean roseto 7.6. However,the number of

previoussurgicalprocedurescouldbeashighas22,asfound inonecaseofinfectionfollowingTKA.Thesedatawere con-cordantwiththosepublishedbyIsiklaretal.10_Nonetheless,

thesedataseemedhighincomparisonwiththemeanof2.8

proceduresprecedingamputationthatwas observedinthe

sampleofPringetal.20

Patientsundergoingtransfemoralamputationdueto com-plicationsfollowingarthroplasty presentlimited functional results,becauseofmultifactorialcauses.Inmostcases,these areelderlypatientswithmultiplejointinvolvementanda vari-etyofcomorbidities.Theenergyconsumptionforlocomotion ishigherthan innormalgait,and givesrise todifficulty in muscleandproprioceptiverehabilitation.

Inourstudy,44%oftheamputatedpatientswerefittedwith prostheses.ThisfindingisconcordantwiththestudybyPring etal.20_However,_it_is_higher_than_what_was_presented_in_the seriesofSierraetal.,15_which_documented_a_rate_of_only_20%, andthefindingsofIsiklaretal.,10_who_reported_that_12.5%_of

thepatientswerefittedwithaprosthesisafteramputation, followingTKA.

Pringetal.20 _reported_that_only_30%_of_the_patients_who underwentamputationwerecapableofwalkingregularly. Isik-laretal.10_corroborated_these_data_and_identified_35%_of_their sampleaswalkers.

Inourseries,62.5%ofthepatientsreportedthattheywere capableofwalking,althoughtheyneededanaid.Amongthe patients without aprosthesis, only33% reportedthat they were walkingregularly,whileinthegroupfittedwith pros-theses,allofthemwereclassifiedaswalkers.

Conclusions

Theincidenceofamputationconsequenttofailureor compli-cationsafter2409TKAprocedureswas0.41%.

The main cause of amputation was recurrent deep

infection, which occurred in 81% of the cases. Vascular

complications and periprosthetic fractures associatedwith metaphysealbonelosswerethecauseofamputationin12.5% and6.5%,respectively.

Onaverage,6.8surgicalprocedureswereperformedprior toamputation.

Thefunctionalresultwaslimited.Fittingofaprosthesis wasachievedin44%ofthepatients,and only62.5%ofthe patientswerecapableofwalking.

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

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1.VerneuilA.Delacréationd’unefaussearticulationpar sectionourésectionpartielledel’osmaxillaireinférieur, commemoyenderémedieral’ankylosevraieoufaussedela machoireinférieure.ArchGenMed.1860;15:174.

2.CoytePC,HawkerG,CroxfordR,WrightJG.Ratesofrevision kneereplacementinOntario,Canada.JBoneJointSurgAm. 1999;81(6):773–82.

3.SharkeyPF,HozackWJ,RothmanRH,ShastriS,JacobySM. InsallAwardpaper.Whyaretotalkneearthroplastiesfailing today?ClinOrthopRelatRes.2002;(404):7–13.

4.Font-RodriguezDE,ScuderiGR,InsallJN.Survivorshipof cementedtotalkneearthroplasty.ClinOrthopRelatRes. 1997;(345):79–86.

5.WeirDJ,MoranCG,PinderIM.Kinematiccondylartotalknee arthroplasty.14-yearsurvivorshipanalysisof208consecutive cases.JBoneJointSurgBr.1996;78(6):907–11.

6.RanawatCS,PadgettDE,OhashiY.Totalkneearthroplastyfor patientsyoungerthan55years.ClinOrthopRelatRes. 1989;(248):27–33.

7.ScuderiGR,InsallJN,WindsorRE,MoranMC.Survivorshipof cementedkneereplacements.JBoneJointSurgBr.

1989;71(5):798–803.

8.FehringTK,OdumS,GriffinWL,MasonJB,NadaudM.Early failuresintotalkneearthroplasty.ClinOrthopRelatRes. 2001;(392):315–8.

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arthroplastyrevision.ClinOrthopRelatRes.2006;446: 45–50.

10.IsiklarZU,LandonGC,TullosHS.Amputationafterfailedtotal kneearthroplasty.ClinOrthopRelatRes.1994;(299):173–8. 11.IncavoSJ,WildJJ,CoughlinKM,BeynnonBD.Earlyrevisionfor

componentmalrotationintotalkneearthroplasty.Clin OrthopRelatRes.2007;458:131–6.

12.GioeTJ,KilleenKK,GrimmK,MehleS,ScheltemaK.Whyare totalkneereplacementsrevised?Analysisofearlyrevisionin acommunitykneeimplantregistry.ClinOrthopRelatRes. 2004;(428):100–6.

13.GonzalezMH,MekhailAO.Thefailedtotalkneearthroplasty: evaluationandetiology.JAmAcadOrthopSurg.

2004;12(6):436–46.

14.KurtzS,OngK,LauE,MowatF,HalpernM.Projectionsof primaryandrevisionhipandkneearthroplastyintheUnited Statesfrom2005to2030.JBoneJointSurgAm.

2007;89(4):780–5.

15.SierraRJ,TrousdaleRT,PagnanoMW.Above-the-knee amputationafteratotalkneereplacement:prevalence, etiology,andfunctionaloutcome.JBoneJointSurgAm. 2003;85(6):1000–4.

16.RandJA,PetersonLF,BryanRS,IlstrupDM.Revisiontotal kneearthroplasty.InstrCourseLect.1986;35:305–18. 17.BengtsonS,KnutsonK.Theinfectedkneearthroplasty.A

6-yearfollow-upof357cases.ActaOrthopScand. 1991;62(4):301–11.

18.FasciaDT,SinganayagamA,KeatingJF.Methicillin-resistant

Staphylococcusaureusinorthopaedictrauma:identificationof riskfactorsasastrategyforcontrolofinfection.JBoneJoint SurgBr.2009;91(2):249–52.

19.SmithDE,McGrawRW,TaylorDC,MasriBA.Arterial complicationsandtotalkneearthroplasty.JAmAcadOrthop Surg.2001;9(4):253–7.