Complications of Total Complications of Total Knee Arthroplasty in BriefKnee Arthroplasty in Brief

D. HaddadD. Haddad

P. KimP. Kim

October 4, 2005October 4, 2005

TopicsTopics

thromboembolismthromboembolism anemia/blood lossanemia/blood loss infectioninfection neurovascularneurovascular wound healingwound healing intra-op MCL injuryintra-op MCL injury arthrofibrosisarthrofibrosis extensor mechanism failureextensor mechanism failure

ThromboembolismThromboembolism

increased risk:increased risk: age >40, estrogen, cancer, prolonged immobility, age >40, estrogen, cancer, prolonged immobility,

CHF, IBD, obesity, smoking , HTN DM, MICHF, IBD, obesity, smoking , HTN DM, MI

prevalence (w/o prophylaxis)prevalence (w/o prophylaxis) DVT : 40-84% DVT : 40-84%

thigh – 9-20%thigh – 9-20% calf DVT will propagate proximal in 6-23%calf DVT will propagate proximal in 6-23%

PE 10-20%PE 10-20% symptomatic 0.5 -3%symptomatic 0.5 -3% mortality up to 2%mortality up to 2%

Thromboembolism:Thromboembolism:DiagnosisDiagnosis

hi index of suspician – most asymphi index of suspician – most asymp routine screening has not proven usefulroutine screening has not proven useful venography – gold standard (97%venography – gold standard (97% duplex ultrasonographyduplex ultrasonography

sensitivity – 20-90% (multicenter study)sensitivity – 20-90% (multicenter study) >90% accurate for proximal>90% accurate for proximal

Thromboembolism:Thromboembolism: Prophylaxis Prophylaxis

recommended in all patients undergoing TKArecommended in all patients undergoing TKA

ASA – DVT rates 59%-73% ASA – DVT rates 59%-73% justification: no diff fatal PE ratesjustification: no diff fatal PE rates

mechanical (e.g. intermittent pneumatic compressive mechanical (e.g. intermittent pneumatic compressive device) – sig reduction proximal DVT device) – sig reduction proximal DVT

warfarin vs LMWH debatewarfarin vs LMWH debate LMWH slightly more effective but more transfusion and slightly LMWH slightly more effective but more transfusion and slightly

increased risk significant bleeding increased risk significant bleeding duration? – 1998 Chest MD Consensus Conference: 7-10 days, duration? – 1998 Chest MD Consensus Conference: 7-10 days,

possible incr benefit if 29-35 dayspossible incr benefit if 29-35 days

Thromboembolism: Thromboembolism: TreatmentTreatment

PE or proximal high risk DVTPE or proximal high risk DVT

IV unfract heparin (2-2.5xcontrol)IV unfract heparin (2-2.5xcontrol) LMWH (lovenox 1.5mg/kg sc od)LMWH (lovenox 1.5mg/kg sc od) coumadin (overlap until INR>2-2.5)coumadin (overlap until INR>2-2.5) IVC filterIVC filter

only if above contraindicatedonly if above contraindicated often requires LT anticoagoften requires LT anticoag not clearly shown to reduce incidence of fatal PE (OKU H and K recon 2)not clearly shown to reduce incidence of fatal PE (OKU H and K recon 2)

conventional durationconventional duration calf DVT 6 wkscalf DVT 6 wks prox DVT 3 moprox DVT 3 mo PE 6 moPE 6 mo

however indefinate Tr reduces recurrence w/ no incr bleeding risk however indefinate Tr reduces recurrence w/ no incr bleeding risk demonstrated at 2-4 y f/udemonstrated at 2-4 y f/u

Post-op Blood Loss/AnemiaPost-op Blood Loss/Anemia

estimate perioperative blood loss of 1.5L estimate perioperative blood loss of 1.5L (cemented) to 2L (uncemented)(cemented) to 2L (uncemented)

dropping tourniquet before closure and dropping tourniquet before closure and use of drain may use of drain may increaseincrease blood loss blood loss

pre-op donation and EPO, and post-op pre-op donation and EPO, and post-op blood salvage can reduce transfusion req. blood salvage can reduce transfusion req.

sig post-op hematoma uncommonsig post-op hematoma uncommon consider holding anticoag consider holding anticoag

Vascular InjuryVascular Injury

RARE (0.03-0.2%) RARE (0.03-0.2%) 14 cases reported in UK from 147 surgeons14 cases reported in UK from 147 surgeons

3 direct trauma (pop a. or branches) – good recovery3 direct trauma (pop a. or branches) – good recovery 11 thrombosis (fem/pop) – 6 required 11 thrombosis (fem/pop) – 6 required amputationamputation no cases of thrombosis without tourniquetno cases of thrombosis without tourniquet

pre-op critical assessment of vascularity importantpre-op critical assessment of vascularity important prev sx, claudication, Ca’n vessels, pulsesprev sx, claudication, Ca’n vessels, pulses

noninvasive vasc studies and vasc. sx consultation noninvasive vasc studies and vasc. sx consultation when indicatedwhen indicated abi < 0.9=consult, <0.5=need for revasc before TKAabi < 0.9=consult, <0.5=need for revasc before TKA

post-op assessment vascularity in all patients – post-op assessment vascularity in all patients – emergent angio/sx if pulses absentemergent angio/sx if pulses absent

Neurological InjuryNeurological Injury

almost synonymous w/ peroneal n. injuryalmost synonymous w/ peroneal n. injury 0.3-4%0.3-4% usually after correction of FFD or fixed valgus (e.g. RA)usually after correction of FFD or fixed valgus (e.g. RA) RF – previous lumb, lumbar laminectomy, severe valgus, RF – previous lumb, lumbar laminectomy, severe valgus,

epidural, previous HTOepidural, previous HTO Tr: release dressing completely and flex knee, AFO if Tr: release dressing completely and flex knee, AFO if

persists; observepersists; observe

OUTCOMEOUTCOME Asp and Rand – 50% pts recovered at 5 y. f/u (more Asp and Rand – 50% pts recovered at 5 y. f/u (more

common in incomplete palsies)common in incomplete palsies) OKU – most partial palsies recover completelyOKU – most partial palsies recover completely Krackow 4/5 pts completely recovered after delayed Krackow 4/5 pts completely recovered after delayed

decompression (5-45 mo)decompression (5-45 mo)

Wound Healing Wound Healing

RF: RF: prior: incisions, direct ant. knee trauma, infectn, prior: incisions, direct ant. knee trauma, infectn,

burns, radiationburns, radiation use of azothioprine, short acting RA medsuse of azothioprine, short acting RA meds immunosuppressionimmunosuppression obesityobesity subcut skin closure w/ polydioxanone (PDS)subcut skin closure w/ polydioxanone (PDS) probs w/ microciruclation (DM,RA)probs w/ microciruclation (DM,RA) prolonged corticosteroidprolonged corticosteroid correction severe deformity (skin on concave side)correction severe deformity (skin on concave side)

PreventionPreventionmain blood supply medialmain blood supply medial anastamoses at fascial levelanastamoses at fascial level less oxygen tension in lateral flap less oxygen tension in lateral flap

as move medialas move medial use of midline incision is use of midline incision is

recommendedrecommended raise flaps raise flaps underunder fascia if necc fascia if necc use of most lateral incision use of most lateral incision

recommended if multiple recommended if multiple incisionsincisions

if new incision if new incision skin bridge 7 skin bridge 7 cmcm

if contracted – consider soft if contracted – consider soft tissue expanderstissue expanders

consider full thickness flap pre-op consider full thickness flap pre-op

TreatmentTreatment

agressively treat early signs of infectionagressively treat early signs of infection low threshold to aspirate kneelow threshold to aspirate knee hold ABic until deep cultures availhold ABic until deep cultures avail early I&Dearly I&D

once prosthesis exposed – aggressive st once prosthesis exposed – aggressive st reconstruction reconstruction excise abnormal skin, gastroc/soleus/free flapexcise abnormal skin, gastroc/soleus/free flap

InfectionInfection

1-2% prevalence1-2% prevalence best preventedbest prevented when diagnosed should be treated when diagnosed should be treated

aggressivelyaggressively RF: immunosuppression, diabetes, RF: immunosuppression, diabetes,

smoking, prior surgery, obesity, smoking, prior surgery, obesity, hinged/highly constrained implanthinged/highly constrained implant

reduced w/ laminar flow; prophylactic reduced w/ laminar flow; prophylactic antibiotics, antibiotic impreg cementantibiotics, antibiotic impreg cement

DefinitionsDefinitions

deep infection=deep to fascia w/ joint deep infection=deep to fascia w/ joint involvementinvolvement

early infection (<6 mo) – early infection (<6 mo) – contamination/wound probcontamination/wound prob

late – heamatogenous seedinglate – heamatogenous seeding more useful in directing Tr: duration of more useful in directing Tr: duration of

symptoms (< or > 2wks)symptoms (< or > 2wks)

DiagnosisDiagnosis

ESR, CRP, bone/wbc scans variably ESR, CRP, bone/wbc scans variably usefuluseful

aspirate all joints suspected of infectionaspirate all joints suspected of infection 100% sensitivity, specificity, and accuracy in 100% sensitivity, specificity, and accuracy in

one study (43 knees)one study (43 knees) AB’ics must be stopped for 10-14 daysAB’ics must be stopped for 10-14 days

TreatmentsTreatments repeated aspirations and AB’icsrepeated aspirations and AB’ics

poor op candidate, dx in 48 hours, pen sensitive organismpoor op candidate, dx in 48 hours, pen sensitive organism component retention w/ I and D and poly exchangecomponent retention w/ I and D and poly exchange

acute post-op (w/in 4/52) or <2 wks (?5 days,?30 days) of symptomsacute post-op (w/in 4/52) or <2 wks (?5 days,?30 days) of symptoms prosthesis exchangeprosthesis exchange

2 stage is standard2 stage is standard remove components/cementremove components/cement aggressive debridement aggressive debridement AB’ic depot AB’ic depot

(articulated spacer)+ IV AB’ics(articulated spacer)+ IV AB’ics insert revision TKA insert revision TKA duration b/w stages controversial – 6 wks and downward trend CRP/ESRduration b/w stages controversial – 6 wks and downward trend CRP/ESR

fusionfusion failure of tr, inad skin/st, resistant organisms, immunocompetentfailure of tr, inad skin/st, resistant organisms, immunocompetent 90% success eradication and fusion90% success eradication and fusion

resection arthroplastyresection arthroplasty non-ambulator/salvagenon-ambulator/salvage

amputationamputation life threatening sepsis or ultimate last resort after all other Tr failedlife threatening sepsis or ultimate last resort after all other Tr failed

Intra-op MCL RuptureIntra-op MCL Rupture

traditionally treated with change to constrained traditionally treated with change to constrained implantimplant

best tr: intra-op repair and continue w/ planned best tr: intra-op repair and continue w/ planned implantimplant

Leopold et al JBJS 2001Leopold et al JBJS 2001 16 pts w/ intra-op MCL injury16 pts w/ intra-op MCL injury all treated primarily with repair or reattachment and all treated primarily with repair or reattachment and

6/52 bracing w/ no ROM restrictions6/52 bracing w/ no ROM restrictions unconstrained implantsunconstrained implants good results re var/val stability,ROMgood results re var/val stability,ROM

StiffnessStiffness

common source of failurecommon source of failure ““remains unsolved problem”remains unsolved problem” best predictor post-op ROM: pre-op ROMbest predictor post-op ROM: pre-op ROM

inconsistent predictors – diagnosis, keloid, prev plateau #, inconsistent predictors – diagnosis, keloid, prev plateau #, prev sxprev sx

intra-op causes (“overstuffing”)intra-op causes (“overstuffing”) improper flexion-extension gap balancing, malpositioning or

oversizing of components, inadequate femoral or tibial resection, excessive joint line elevation, creation of an anterior tibial slope, or incompletely resected posterior osteophytes.

post-op causespost-op causes patient motivation and compliance, deep infection,

arthrofibrosis, patellar comp, CRPS, HO

TreatmentTreatment JAAOS 2004JAAOS 2004

Extensor Mechanism FailureExtensor Mechanism Failure

quads rupture – extremely rarequads rupture – extremely rare patellar tendon (ligament) rupturepatellar tendon (ligament) rupture

one of most dreaded complicationsone of most dreaded complications <1%<1% intraop- everting stiff ext mechintraop- everting stiff ext mech postop – trauma, chronic attritionpostop – trauma, chronic attrition best TR is preventionbest TR is prevention Tr unreliable and generally unsatisfying resultTr unreliable and generally unsatisfying result

Tr: Tr: acute: primarily if avulsion and intact periosteal sleeve (+/- acute: primarily if avulsion and intact periosteal sleeve (+/-

semiT augment)semiT augment) chronic: reconstruction w/ Achilles allograft preferred Tr for most chronic: reconstruction w/ Achilles allograft preferred Tr for most

authors @ presentauthors @ present

Patellar FracturePatellar FractureJAAOS 2003JAAOS 2003

Peace OutPeace Out