Long-term results of allograft composite total hip prostheses for tumors.

The functional results of standard reconstruction prostheses are impaired by instability because of poor muscular reinsertion, especially of the gluteal muscles. In 21 patients, composite hip prostheses including proximal femoral allografts were used after primary malignant tumor resection. Ten reconstructions used combined bone-tendon allografts that allowed reinsertion of the gluteal muscles to the allograft tendons. None of the 21 patients had dislocation or infection. Ten patients died within 2 years of surgery without complications requiring reoperations. The mean followup in the 11 other patients was 10 years. Eight patients had reoperation: four for loosening (two at 3 years, two at 11 and 12 years), and four had autologous graftings for nonunion of the trochanter or of the distal graft-bone interface. Evaluation of function in the 11 patients with follow-ups ranging from 4 to 15 years showed an average Musculoskeletal Tumor Society score of 77%. Satisfactory strength of the abductor muscles was achieved by reinsertion of the trochanter or by suture of the patients gluteal muscles with the combined tendon-bone allograft. At long-term, radiologically, the bony allograft showed no change in five patients, very mild resorption in five, and severe resorption in one. Stem fixation was excellent in 10 patients and fair in one. Comparison between the functional results of reconstruction prostheses versus composite prostheses showed a significant improvement with the composite prosthesis. In the authors' institution, at 10 years, the mechanical survival of composite prostheses was 81%, as compared with only 65% for reconstruction prostheses.