Infected Prostheses after Lower-Extremity Bone Tumor Resection: Clinical Outcomes of 100 Patients

BACKGROUND: Infection of megaprostheses after bone tumor resection is a major concern; management is challenging. This study evaluated the survivability from such infections, the microbial isolates, treatment tactics, and outcome of megaprosthesis reconstructions. MATERIALS AND METHODS: We studied 1,161 patients retrospectively who underwent megaprosthesis reconstruction for limb salvage after a sarcoma from 1983 to 2010. The mean followup was 9 y (range 3-20 y). We evaluated the overall survival of the megaprosthesis reconstructions in patients with infection and the survival with respect to the type of megaprosthesis, site of reconstruction, cemented or cementless fixation, type of tumor, adjuvant treatments, microbial isolate(s), treatment tactics, and outcome. RESULTS: The incidence of infection was 8.6%. The most common microbial isolate was Staphylococcus epidermidis (47%). Overall survival with definitive management of infection was 88% at 10 y and 84% at 20 y. Survival was higher for cementless reconstructions and not different with respect to the type of megaprosthesis, site of reconstruction, or adjuvant therapy. Infections resolved completely with one- or two-stage surgery in 75% of patients. The rate of amputation because of infection was 21%. CONCLUSIONS: Megaprosthesis reconstructions may be infected in 8.6% of cases. Infections more commonly occur late, caused usually by S. epidermidis. The survival rate is higher with cementless megaprosthesis reconstructions and no different with respect to the type of tumor or megaprosthesis or the adjuvant treatments. One-stage revision is effective for acute post-operative infections; however, two-stage revision surgery is necessary for early and late infections. The rate of amputation because of occurrence or persistence of megaprosthesis infection is 21%.