Long-term followup of uncemented tumor endoprostheses for the lower extremity

Between 1982 and 1989, 100 primary lower limb reconstructions were done usi ng the Kotz Modular Femur Tibia Reconstruction System after resection of a malignant tumor, In 32 patients a proximal femur prosthesis was implanted, in 40 patients a distal femur prosthesis was implanted, in 19 patients a pr oximal tibia component was implanted, in four patients a total femur prosth esis was implanted, and in five patients a total knee prosthesis was implan ted. The Kaplan-Meier estimate of the overall survival rate of the prosthes es was 85% after 3 years, 79% after 5 years, and 71% after 10 years. The mo st common reason for implant failure was aseptic loosening in 27% of patien ts (11 patients; range, 10-121 months) after the initial operation. The oth er reasons for revision surgery were implant fracture (n 5 4) and infection (n 5 4). Early repair of prostheses-related minor complications, such as w orn polyethylene bushings, resulted in a statistically significant reductio n of implant failure. After a median followup of 127.5 months after the ini tial surgery, 51 patients had died and eight patients were lost to followup . Forty-one patients were evaluated clinically and radiologically using the Musculoskeletal Tumor Society score and the radiologic implant evaluation system of the International Symposium on Limb Salvage; these 41 patients ha d a mean of 80 % (range, 40 %-100 %) of the normal functional capability.