Outcomes of acute vs. delayed reverse shoulder arthroplasty for proximal humerus fractures in the elderly: a systematic review and meta-analysis

Hypothesis: Reverse shoulder arthroplasty (RSA) has become an increasingly popular treatment option for proximal humerus fractures in the elderly. There is however contradictory evidence on the impact of timing of RSA on patient outcomes. It remains unclear if poor results after initial nonsurgical or surgical management can be improved with delayed RSA. The aim of this systematic review and meta -analysis is to compare the outcomes of acute RSA and delayed RSA for the treatment of proximal humerus fractures in the elderly.Materials and Methods: A systematic search was performed on 4 databases for studies that compared acute RSA with RSA used after prior nonoperative or operative treatment. Studies with a mean cohort age of <65 years were excluded. Demographical data, clinical outcome scores, range of motion measurements, and postoperative complications were collected from the included studies.Results: Sixteen studies were included for data analysis. Compared with delayed RSA cohorts, acute RSA cohorts had higher forward flexion (124.3 & DEG; vs. 114.9 & DEG;; P =.019), external rotation (24.7 & DEG; vs. 20.2 & DEG;; P =.041), and abduction (113.2 & DEG; vs. 99.8 & DEG;; P = .03). Compared with RSA after conservative management, acute RSA had greater external rotation (29.9 & DEG; vs. 21.4 & DEG;; P = .043). The acute RSA cohort had significantly higher American Shoulder and Elbow Surgeons (76.4 vs. 68.2; P = .025) and Constant-Murley scores (65.6 vs. 57.3; P = .002) compared with the delayed RSA cohort. Subgroup analyses showed significantly greater Constant-Murley (64.9 vs. 56.9; P = .020) and Simple Shoulder Test scores (8.8 vs. 6.8; P = .031) with acute RSA compared with RSA after conservative treatment. The American Shoulder and Elbow Surgeons score was higher in the acute RSA cohort compared with RSA after open reduction in-ternal fixation (77.9 vs. 63.5; P = .008). The overall complication rate per 100 patient-years was 11.7 for the acute RSA cohort and 18.5 for the delayed RSA cohort (risk ratio: 0.55; P = .015).Conclusion: Based on the current evidence, acute RSA presents better clinical outcome measures and range of motion measurements, with decreased complication rates than RSA performed after prior nonoperative or operative treatment. Level of evidence:Level III; Systematic Review & COPY; 2023 The Author(s). This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).