Large tumor endoprostheses and extracortical bone-bridging: 28 patients followed 10-20 years

Aseptic loosening is a common cause of failure in large tumor endoprostheses. The concept of extracortical bone-bridging was developed to tackle the problem of loosening. New bone which forms across the junction of the bone-prosthesis junction is believed to improve fixation by controlling the transfer of stresses across the junction as well as by giving additional stability to the prosthesis. We present the long-term experience with this concept following major reconstruction after tumor and non-tumor conditions in 31 patients. The overall function was good for upper and lower limb prostheses. Most patients had extracortical bone bridging which was maintained for over 10 years. In 1/3 of patients this involved over 75% of the prosthetic circumference. Prosthetic survival was best with intercalary devices, followed by proximal femoral and distal femoral prostheses. Survival of prostheses in young active patients was similar to that reported in older patients undergoing primary joint replacement.