Revision shoulder arthroplasty with a reverse shoulder prosthesis : Use of structural allograft for glenoid bone loss.

INTRODUCTION: Revision shoulder arthroplasty presents many unique and complex challenges when glenoid bone loss is involved. A distorted and medialized anatomy prevents the proper mechanics of the reverse prosthesis with regard to deltoid tension and ultimate function. This paper highlights one surgeon's experience using structural allograft for glenoid bone loss. PATIENTS AND METHODS: In all, 20 patients for a total of 24 surgeries with a medialized glenoid and/or substantial glenoid bone loss of grade IIB or higher were evaluated in this retrospective study. The allograft surgeries were performed as a one-stage procedure except for three patients. Recombinant human bone morphogenetic protein-2 (BMP2) was added to supplement incorporation in all cases. Four patients had two separate allograft procedures. Eight of the allograft procedure were femoral shaft, eleven of the allografts were femoral neck/head, and five of the allograft procedures were from proximal humerus. A graft was considered a success if they had at least 12 months of clinical and radiographic follow-up without subsequent removal of the graft or radiographic failure. Patients with less than 12 months of follow-up were included if the graft was removed or had early failure.
RESULTS: All femoral shaft allografts except one failed, and during revision surgery it was often noted that the graft was cracked where the peripheral screws had been drilled. In nine patients the graft was still in place at last follow-up, seven of these were femoral neck/head allografts. Five grafts were removed secondary to infection. Average follow-up was 24 months (range 5-45 months).
CONCLUSIONS: Femoral neck allografts are an option in patients with substantial bone loss. The authors do not recommend use of femoral shaft allografts.