Survival of Tumor Megaprostheses Replacements about the Knee

Limb salvage surgery is an effective procedure with a low risk of tumor recurrence. In an attempt to define the incidence of implant failure at 2, 5, and 10 years postoperatively, we retrospectively reviewed implant survival in a group (n = 105) of pediatric (< 18 years of age) and adult patients who were treated with distal femoral and/or proximal tibial implants for extremity tumors. Issues regarding the timing of failure, reason for failure, and whether pediatric patients had higher rates of failure were posed as secondary questions. The median followup was 57 months (1-235 months). Thirty-two (32/105, 31%) patients had 42 implant failures. The mean prosthesis Kaplan-Meier survivorship of the index group was 84% at 2 years, 73% at 5 years, and 59% at 10 years. Forty-seven percent of all failures occurred within 2 years postoperatively, and 69% occurred within 5 years postoperatively. Pediatric patients had a higher failure rate than adults (42% versus 24%). Aseptic loosening was the most common reason for failure (n = 18/32; 56%). The incidence of failure in tumor megaprostheses is similar to early published literature and the incidence of these failures is highest within the first 3 years.

Level of Evidence: Therapeutic study, level IV. See Guidelines for Authors for a complete description of levels of evidence.