Reverse shoulder replacement is a surgical option for cuff tear arthropathy. However scapular notching is a concern. Newer designs of glenospheres are available to reduce scapular notching. Eccentric glenosphere with a lowered centre of rotation have been shown to improve range of adduction in vitro. We hypothesize that the eccentric glenosphere improve clinical outcomes and reduce scapular notching. This is an ongoing randomized controlled double blind prospective clinical trial. Patients 70 years or older at North Shore hospital who have a diagnosis of cuff tear arthropathy and require surgery were consented for this study. Patients were allocated a concentric or eccentric 36 mm glenosphere intraoperatively, using a computer generated randomization contained in a sealed envelope. The surgical technique and post operative rehabilitation were standardized. Patients were followed up by a research nurse and postoperative radiographs were also taken at regular intervals. Clinical assessment include a visual analogue pain score, subjective shoulder rating, American Shoulder and Elbow Society Score, and Oxford shoulder score. Complications were checked for and radiographs were assessed for scapular notching.Introduction
Method
We used an inverted shoulder arthroplasty in 43 consecutive patients with a mean age of 78 years (65 to 97) who had sustained a three- or four-part fracture of the upper humerus. All except two were reviewed with a mean follow-up of 22 months (6 to 58). The clinical outcome was satisfactory with a mean active anterior elevation of 97° (35° to 160°) and a mean active external rotation in abduction of 30° (0° to 80°). The mean Constant and the mean modified Constant scores were respectively 44 (16 to 69) and 66% (25% to 97%). Complications included three patients with reflex sympathetic dystrophy, five with neurological complications, most of which resolved, and one with an anterior dislocation. Radiography showed peri-prosthetic calcification in 36 patients (90%), displacement of the tuberosities in 19 (53%) and a scapular notch in ten (25%). Compared with conventional hemiarthroplasty, satisfactory mobility was obtained despite frequent migration of the tuberosities. However, long-term results are required before reverse shoulder arthroplasty can be recommended as a routine procedure in complex fractures of the upper humerus in the elderly.
