Why do patients with anterior shoulder instability not return to sport after surgery? A systematic review of 63 studies comprising 3545 patients

Purpose: To review athletes’ reasons not to return to sport (RTS) after surgical treatment of anterior shoulder instability, comparing capsulolabral repair and bony reconstruction procedures. The hypothesis is that the most common reason for patients unable to RTS is not due to physical inability of the shoulder. Methods: A systematic review was performed using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines. PubMed, Embase/Ovid, Cochrane Database of Systematic Reviews/Wiley, Cochrane Central Register of Controlled Trials/Wiley, SPORTDiscus/Ebsco, and Web of Science/Clarivate Analytics were searched in collaboration with an information specialist up to August 11, 2022. Observational and interventional studies reporting reasons for no RTS following surgical treatment of anterior shoulder instability were included. Quality assessment of studies was conducted using the Methodological Index for Non-Randomized Studies (MINORS) criteria and Risk of Bias (RoB) assessment. Forest plots were generated to show an overview of the proportion shoulder function independent reasons for each study. Results: Sixty-three studies were included reporting on 3545 athletes, of which 2588 (73%) underwent capsulolabral repair versus 957 (27%) who underwent surgical treatment with bony reconstruction procedures. A total of 650 athletes (18%) were unable to RTS. The reason not to RTS was most frequently shoulder function independent (70%) compared to shoulder function dependent (30%) following both capsulolabral repair and bony reconstruction procedures. Most cited reasons for no RTS after capsulolabral repair were fear of reinjury (17%), personal reasons or change of priorities (11%) and retirement/discharge of military service or sports team (10%). Of these reasons, 106 (22%) were not specified other than being shoulder function dependent or shoulder function independent. Most cited reasons for no RTS after bony reconstruction procedures were fear of reinjury (12%), shoulder pain (10%), and retirement/discharge of military service or sports team (9%). Of these reasons, 74 (44%) were not specified other than being shoulder function dependent or shoulder function independent. Forest plots showed a variation from 0% to 100% shoulder independent reasons for both capsulolabral repair and bony reconstruction procedures. Conclusion: The majority of athletes who did not RTS following surgical treatment for anterior shoulder instability did so due to shoulder function independent reasons, such as fear of reinjury. However, there was a high variety between studies and many reasons were unspecified, warranting unified definitions for reasons of patients that do not RTS.