Hydroxyapatite-coated distal femoral replacements. Preliminary results

A custom-designed, hydroxyapatite-coated distal femoral replacement was developed and implanted in five individuals at the authors' hospital. The indications for this type of prosthesis were a multiply failed cemented endoprosthesis in two individuals; a revision of an infected, previously cemented endoprosthesis in another; a primary low-grade sarcoma in a fourth, and a stage III giant cell tumor in the final individual. Mean follow-up time was 3.3 years (range, 2.9-3.5 years). The functional results, based on the Musculoskeletal Tumor Society (MSTS) criteria, were excellent in one patient (20%) and good in four patients (80%). Musculoskeletal Tumor Society functional scores ranged from 25 to 35 (mean, 29.8). No patient had thigh pain. All the femoral components appeared well fixed on radiographic evaluation. These preliminary results indicate that a hydroxyapatite-coated distal femoral replacement may represent a viable alternative to a cemented endoprosthesis for aggressive benign lesions and low-grade sarcomas requiring resection. In addition, it appears to be a viable solution for failed cemented endoprostheses in individuals who have survived their disease.