Results of 32 allograft-prosthesis composite reconstructions of the proximal femur

Abstract

The use of allograft-prosthesis composites for reconstruction after bone tumor resection at the proximal femur has generated considerable interest since the mid1980s on the basis that their use would improve function and survival, and restore bone stock. Although functional improvement has been documented, it is unknown whether these composites survive long periods and whether they restore bone stock. We therefore determined long-term allograft-prosthesis composite survival, identified major complications that led to revision, and determined whether allograft bone stock could be spared at the time of revision. We also compared the radiographic appearance of allografts sterilized by gamma radiation and fresh-frozen allografts. We retrospectively reviewed 32 patients with bone malignancy in the proximal femur who underwent reconstruction with a cemented allograft-prosthesis composite. The allograft-prosthesis composite was a primary reconstruction for 23 patients and a revision procedure for nine. The minimum followup was 2 months (median, 68 months; range, 2-232 months). The cumulative incidence of revision for any reason was 14% at 5 years (95% confidence interval, 1%-28%) and 19% at 10 years (95% confidence interval, 3%-34%). Nine patients (28%) had revision of the reconstruction during followup; four of these patients had revision surgery for infection. Allografts sterilized by gamma radiation showed worse resorption than fresh-frozen allografts. Based on reported results, allograft-composite prostheses do not appear to improve survival compared with megaprostheses.

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

Fig. 1

This graph shows the cumulative probability of revision for mechanical or infectious reasons and of death. The cumulative incidence of revision for any reason was 19% at 10 years (95% confidence interval, 3%-34%), and the cumulative incidence of revision for mechanical reasons was 4% at 10 years. Infection is an important cause for revision.

Fig. 2A–D

(A) This radiograph shows an allograft-composite prosthesis after resection of a chondrosarcoma of the right proximal femur. (B) The immediate postoperative and (C) 16-year postoperative AP and (D) lateral radiographs show allograft resorption, allograft-host bone nonunion, and stem loosening with time. Some mismatch between the allograft and host femur can be seen on the postoperative radiograph.

Fig. 3A–D

(A) This radiograph shows an allograft-composite prosthesis after resection of a malignant fibrous histiocytoma of the left proximal femur. (B) The immediate postoperative and (C) 7-year postoperative AP and (D) lateral radiographs show allograft-host bone union and absence of allograft resorption with time.