INFECTED TOTAL KNEE ARTHROPLASTY - 2-STAGE REIMPLANTATION WITH A GASTROCNEMIUS ROTATIONAL FLAP

This study reviews a consecutive series of 21 patients undergoing two- stage reimplantation total knee arthroplasty for late chronic infectio n. All 21 patients had late chronic infections, and 20 of 21 patients were compromised hosts. Seven different organisms were isolated at the time of prosthetic resection. Staphylococcus coagulase negative speci es was the most frequently isolated organism. At the time of reimplant ation, a medial gastrocnemius rotational flap was rotated over the pro ximal tibia and knee for wound closure. The average explantation time was 25 weeks (range, 7-76 weeks), and no methylmethacrylate spacers we re used. At an average 17-month followup (range, 5.1-33.1 months) all reimplanted total knee replacements remained in place with one patient having recurrent infection. At reimplantation, 11 patients had positi ve bacterial cultures from tissue specimens, Sixteen of the 33 (40%) p ositive cultures were from specimens taken from the medullary canal, A t followup, the average Knee Society Score was 77.4 (range, 40-100). T he lack of a methylmethacrylate spacer and a long explantation time we re considered important factors in diminishing functional performance and determining the need for a gastrocnemius flap, A medial gastrocnem ius rotational flap should be considered at the time of reimplantation total knee arthroplasty if the soft tissue envelope about the knee is compromised and cannot be closed without undue tension.