Infected total knee arthroplasties.

Thirty infected total knee arthroplasties were investigated in 29 patients over an average interval of 42 months. Eleven infections began in the immediate perioperative period. Six developed from postoperative wound-healing problems. The remainder were late infections. Staphylococcus was found in 16 infections, gram-negative agents in five, mixed organisms in five, and other gram-positives in four. Sixteen knees were arthrodesed, six knees were treated by retention of the components, and two above-knee amputations and one resection arthroplasty were performed. Five patients had two-stage revisions to new components. Evidence of persistent infection was present in three arthrodeses, two retained arthroplasties, and one knee that was revised. Perioperative infections were associated with staphylococcal organisms and responded less favorably to conservative treatment. The failure of primary wound healing demands immediate measures to obtain skin coverage. Retention of the arthroplasty components is possible only in selected patients.