Reverse Shoulder Arthroplasty in Patients With Rheumatoid Arthritis and Polymyalgia Rheumatica: A Clinical and Functional Review at Two Years.

Rheumatoid arthritis (RA) and polymyalgia rheumatica (PMR) are chronic inflammatory conditions that can lead to destruction and disability of the glenohumeral joint, requiring joint replacement. Disease processes can lead to further joint erosion and eventual loosening of the glenoid component of an anatomical total shoulder arthroplasty. The use of reverse shoulder arthroplasty (RSA) for RA is widely discussed; however, there is a lack of evidence relating to the use of this procedure for PMR. We conducted this study to compare outcomes of RSA in the treatment of RA and PMR. We conducted a retrospective analysis of 30 RSA procedures, of which 18 were for RA and 12 were for PMR. All patients had significant rotator cuff damage. All patients received the same implant and the same rehabilitation protocol and were followed up at the same four intervals. At each follow-up, we assessed the range of motion and Oxford shoulder score (OSS) and undertook a radiological assessment. We found a significant increase in the reported OSS and range of motion in both groups. We noted improvements in forward flexion, abduction and external rotation in both groups. We identified a significant increase in the OSS and post-operative range of motion after RSA in patients with RA when compared to PMR. In conclusion, RSA remains a viable option for patients with inflammatory arthritis. However, patients with PMR show less pronounced improvement compared to those with RA.