Does primary treatment of proximal humerus fractures show favourable functional outcomes over secondary treatment with reverse shoulder arthroplasty?

Background: This multicentre retrospective cohort study assessed whether functional outcomes after primary reverse shoulder arthroplasty (RSA) are favourable compared to secondary placement in elderly patients with displaced proximal humerus fractures (PHFs). Methods: Fifty-three patients with primary and 32 with secondary RSA were included. Patient-reported outcome measures (PROMs) were assessed: Constant-Murley Score (CMS), Oxford Shoulder Score (OSS), Disabilities of the Arm, Shoulder and Hand (DASH) score, and Visual Analogue Scale (VAS). In addition, range of motion (ROM) was compared between groups. Result: For PROMs, the means (SD) for primary versus secondary were 25.4 (17.7), 29.4 (19.2) for DASH; 38 (8.6), 38 (9.1) for OSS; 63 (19.8), 59 (22.0) for CMS and 2 (2.0), 3 (2.3) for VAS. For ROM, the means were the following: forward flexion 113° (33.6), 106° (34.1); abduction 103° (33.4), 96° (37.3) and external rotation 20° (19.1), 20° (17.8). There were significant differences in favour of primary treatment in forward flexion (p = 0.003, B 19.85) and abduction (p = 0.034, B 17.34). Discussion: ROM in patients with complex displaced PHFs after primary RSA is slightly better than that after secondary treatment. Therefore, RSA could be considered primary treatment, especially when optimal ROM is of great importance to the patient. Level of evidence: level III, retrospective comparative study treatment study.