Mid-term Clinical Outcomes after Reversed Shoulder Arthroplasty are Comparable between Older Patients with Rheumatoid Arthritis and those with Osteoarthritis

Background: To investigate the clinical outcomes of reverse shoulder arthroplasty (RSA) in patients with rheumatoid arthritis (RA), using patient-reported outcome (PRO) measures, and compare the finding to those in patients with osteoarthritis (OA). Materials and Methods: The study included 24 patients (11 with RA and 13 with OA) who underwent primary RSA with a minimum of 2 years of follow-up. Clinical data, including range of motion (ROM; flexion, abduction, external rotation, and internal rotation) and PRO measures (Shoulder36 questionnaire and disability/symptom scale in Quick Disability of the Arm, Shoulder, and Hand [QuickDASH-DS]), were assessed. Results: ROM, Shoulder36 scores (except sports ability scores), and QuickDASH-DS in the RA group, and ROM (expect internal rotation), Shoulder36 scores (except general health scores), and QuickDASH-DS scores in the OA group were significantly improved at follow-up than the preoperative state. At follow-up, there was no significant difference found in any of the variables between the RA and OA groups (flexion: 116.4° vs. 133.1°, P = 0.102; abduction: 100.5° vs. 120.8°, P = 0.159; pain score in Shoulder36: 1.8 vs. 2.1, P = 0.397; ROM score in Shoulder36: 2.1 vs. 2.1, P = 0.578; muscle strength in Shoulder36: 1.8 vs. 1.9, P = 0.680; QuickDASH-DS score: 48.1 vs. 32.7, P = 0.059). Conclusion: The mid-term clinical results after RSA were comparable between patients with RA and those with OA. RSA can be considered the surgical treatment of shoulder in both patients with RA and those with OA.