Revision Arthroplasty with Use of a Reverse Shoulder Prosthesis-allograft Composite

Background: Patients with disabling pain and loss of shoulder function with associated proximal humeral bone loss following shoulder arthroplasty have limited reliable treatment options. Our objective was to report the results, obtained as part of a prospective outcomes study, of the use of a reverse shoulder prosthesis-allograft composite in these patients.

Methods: Between 2002 and 2005, 353 patients treated with a reverse shoulder prosthesis were enrolled in a prospective cohort study. Twenty-five patients received, in addition, a proximal humeral allograft for the management of severe proximal humeral bone loss, and they comprise the study group. The average bone loss measured 53.6 mm (range, 34.5 to 150.3 mm). Patients were followed clinically with use of the American Shoulder and Elbow Surgeons (ASES) score, the Simple Shoulder Test (SST), and a scale with which the patients rated their satisfaction, and they were followed radiographically to detect mechanical failure, loosening, notching, and graft healing. All patients were followed for a minimum of two years (average, 30.2 months).

Results: The total average ASES score improved from 31.7 points preoperatively to 69.4 points at the time of follow-up (p < 0.0001), and the average SST score improved from 1.4 to 4.5 points (p < 0.0001). Nineteen patients (76%) reported a subjective good or excellent result, five reported a satisfactory result, and one reported that the result was unsatisfactory. The range of motion improved in forward flexion (from 32.7 degrees to 82.4 degrees ; p < 0.0001), abduction (from 40.4 degrees to 81.4 degrees ; p < 0.0001), and internal rotation. Radiographic evaluation at the time of final follow-up showed incorporation of the allograft in the metaphyseal region in 84% (twenty-one) of the twenty-five patients and incorporation of the allograft in the diaphyseal region in 76% (nineteen) of the patients. Four patients had complications.

Conclusions: Use of a reverse shoulder prosthesis-proximal humeral allograft composite for the treatment of shoulder dysfunction following arthroplasty associated with substantial proximal humeral bone loss has shown promising early results. The allograft may restore proximal humeral bone stock, thereby helping to maintain the height of the prosthesis bone construct and thus deltoid tension. Additional, long-term studies are needed to evaluate the longevity of this construct.