7 - Infection in total knee arthroplasty

Abstract

Total knee arthroplasty (TKA) has been proven one of the most successful operations of all medicine with very good and long-lasting functional outcome in patients who suffer from osteoarthritis of the knee. The number of TKAs worldwide has increased dramatically. Prosthetic joint infection after TKA is a very serious and challenging complication that can drastically affect patients’ lives, as it may lead to persistent pain and disability, multiple operations with attendant morbidity, and prolonged convalescent periods. The reported incidence for TKA varies from 1% to 2% at 2 years post-operatively, but becomes higher with longer f-up nearing to 7% after revision surgery. Risk factors include presence of systemic or local active infection in an arthritic knee; previous operative procedures in the same knee, diabetes mellitus, malnutrition, smoking, alcohol consumption, co-morbidities, and immunosuppression; end-stage renal disease on hemodialysis, liver disease, intravenous drug abuse, and low safety operative room environment. Diagnosis is established when two cultures of periprosthetic tissue turn positive with identical organisms, or in the presence of sinus tract communicating with the joint or when three of the following minor criteria exist: an elevated serum CRP and ESR, an elevated synovial fluid white blood cell count and ++change on the leukocyte esterase test strip, or a positive alpha-defensin test in the joint aspirate, elevated synovial fluid polymorphonuclear neutrophil percentage, a positive histological analysis of periprosthetic tissue, or a single positive culture. Management of the infected TKA remains difficult for both a surgeon and a patient. It includes continuous suppression with antibiotic antiadministration in selected patients, exchange (revision) TKA in one- or two-stages, arthrodesis of the knee or even amputation. If the appropriate indications are followed, the outcome of management of an infected TKA can be very satisfactory.