TREATMENT OF INFECTED TOTAL KNEE ARTHROPLASTY USING AN ARTICULATING SPACER

Twenty-six patients with late infected total knee arthroplasties were treated by debridement and removal of components and all cement, prese rving collateral ligaments, At time of debridement, an articulating sp acer was fashioned to allow partial weightbearing and knee range of mo tion (ROM) during rehabilitation, This spacer was implanted using anti biotic-impregnated bone cement, For this purpose, 4.8 g of powdered to bramycin was mixed with each 40-g batch of Simplex cement. Cement was applied early to the components, but applied late to the femur, tibia, and patella to allow molding to the defects and bone without adherenc e to bone. Patients received tailored intravenous antibiotic therapy f or 6 weeks in addition to this antibiotic-impregnated cement for treat ment of a variety of gram positive and gram negative organisms. All pa tients had cemented revision total knee arthroplasty using antibiotic- impregnated cement with standard cementing techniques used. All patien ts but 1 had reimplantation; this patient died of unrelated causes bef ore revision. Range of motion before revision was 10 degrees to 95 deg rees. Followup averaged 30 months (range, 13-70 months). The average M odified Hospital for Special Surgery Knee Score after revision was 87 points (range, 53-100 points), with 92% good to excellent results. Ran ge of motion after reimplantation was 50 to 106 degrees. There have be en no recurrences of infection. Use of an articulating spacer to treat infected total knee arthroplasty improves ultimate ROM and soft tissu e health and significantly decreases the risk of reinfection.