Fixation with Philos plates preserves achieved reduction, and a good functional outcome can be expected. However, complication incidence proportions are high, particularly due to primary and secondary screw perforations into the glenohumeral joint, with an overall complication rate of 35%. More accurate length measurement and shorter screw selection should prevent primary screw perforation. Awareness of obtaining anatomic reduction of the tubercles and restoring the medial support should reduce the incidence of secondary screw perforations, even in osteopenic bone.

Background and purposeDespite good clinical results with the reverse total shoulder arthroplasty, inferior scapular notching remains a concern. We evaluated 6 different solutions to overcome the problem of scapular notching.MethodsAn average and a “worst case scenario” shape in A-P view in a 2-D computer model of a scapula was created, using data from 200 “normal” scapulae, so that the position of the glenoid and humeral component could be changed as well as design features such as depth of the polyethylene insert, the size of glenosphere, the position of the center of rotation, and downward glenoid inclination. The model calculated the maximum adduction (notch angle) in the scapular plane when the cup of the humeral component was in conflict with the scapula.ResultsA change in humeral neck shaft inclination from 155° to 145° gave a 10° gain in notch angle. A change in cup depth from 8 mm to 5 mm gave a gain of 12°. With no inferior prosthetic overhang, a lateralization of the center of rotation from 0 mm to 5 mm gained 16°. With an inferior overhang of only 1 mm, no effect of lateralizing the center of rotation was noted. Downward glenoid inclination of 0º to 10º gained 10°. A change in glenosphere radius from 18 mm to 21 mm gained 31° due to the inferior overhang created by the increase in glenosphere. A prosthetic overhang to the bone from 0 mm to 5 mm gained 39°.InterpretationOf all 6 solutions tested, the prosthetic overhang created the biggest gain in notch angle and this should be considered when designing the reverse arthroplasty and defining optimal surgical technique.

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Background Many patients with rheumatoid arthritis develop superior migration of the humeral head because of massive cuff tears, causing loss of active motion. Reverse shoulder arthroplasty could potentially restore biomechanical balance but a high incidence of glenoid failure has been reported. These studies do not, however, typically include many patients with rheumatoid arthritis (RA) and it is unclear whether the failure rates are similar. Questions/purposes We therefore (1) evaluated pain relief and shoulder function after reverse arthroplasty in RA; (2) compared results between primary and revision procedures; (3) determined the incidence of scapular notching; and (4) determined the complication rate. Methods We identified 29 patients with RA who had 33 reverse arthroplasties from among 412 patients having the surgery. Six patients were lost to followup. Twenty three patients (27 shoulders) were evaluated after a minimum followup of 18 months (mean, 56 months; range, 18-143 months), including 18 primary and nine revision arthroplasties. All patients were evaluated preoperatively and 23 shoulders postoperatively by an independent physiotherapist and four were assessed postoperatively by phone. Level of pain, range of motion, and ConstantMurley score were recorded and new radiographs taken.

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