Return to Sport After Acromioclavicular Injury: A Systematic Review of Modifiable Factors

Background: Acromioclavicular joint (ACJ) injuries are common in athletes, particularly in contact and collision sports, and frequently cause time lost from play. Although functional outcomes are well described, return to sport (RTS) is inconsistently reported, and the influence of treatment modality, surgical technique, and rehabilitation strategy on RTS outcomes remains uncertain. Methods: A systematic review was conducted following PRISMA guidelines registered in PROSPERO (ID 1155609). PubMed, Embase, Scopus, Web of Science, and Cochrane were searched for studies from 2015-2025 reporting at least one RTS metric (time, rate, or return to pre-injury level) after ACJ injury. Data on injury classification, surgical technique, rehabilitation protocols, and RTS outcomes were extracted. Results: Twenty-five studies (1077 patients) were included. The pooled RTS rate was 90.8% (95% CI, 88.6-93.0), with 87.7% (95% CI, 84.5-90.9) returning to their pre-injury level. The overall mean RTS time was 125.0 ± 63.05 days (4.5 months). Non-operative treatment was associated with faster RTS (52 days [95% CI, 47-58]) compared with operative management (127 days [95% CI, 114-140]). Among surgical techniques, allograft reconstruction demonstrated slightly higher rates of RTS at pre-injury level (84.2%) versus non-allograft approaches (78.9%). Rehabilitation timing was also influential: protocols initiating strengthening within 6 weeks were associated with faster RTS (93 vs. 132 days) and higher pre-injury RTS rates (86.8% vs. 72.7%). Conclusions: Most athletes return to sport after ACJ injury, with high RTS rates across treatment approaches. Earlier surgery, allograft reconstruction, and early strengthening show associative trends toward faster and more complete RTS, though these findings should be interpreted cautiously due to heterogeneity and confounding with existing data. Standardized RTS definitions, consistent rehabilitation reporting, and prospective comparative studies are needed to clarify which modifiable factors most influence recovery and return to play.