Arthroscopic stabilization surgery for first-time anterior shoulder dislocations: a systematic review and meta-analysis

Background The optimal management of first-time anterior shoulder dislocations (FTASDs) remains controversial. Therefore, the purpose of this study was to assess the efficacy of arthroscopic stabilization surgery for FTASDs through a systematic review and meta-analysis of existing literature. Methods MEDLINE, EMBASE and Web of Science were searched from inception to December 18, 2022, for single-arm or comparative studies assessing FTASDs managed with arthroscopic stabilization surgery following first time dislocation. Eligible comparative studies included studies assessing outcomes following immobilization for a FTASD, or arthroscopic stabilization following recurrent dislocations. Eligible levels of evidence were I to IV. Primary outcomes included rates of shoulder re-dislocations, cumulative shoulder instability as well as subsequent shoulder stabilization surgery. Results Thirty-four studies with 2,222 shoulder dislocation were included. Of these, five studies (n=408 shoulders) were randomized trials comparing immobilization to arthroscopic Bankart repair (ABR) after a first dislocation. Another 16 studies were non-randomized comparative studies assessing arthroscopic Bankart repair following first time dislocation (ABR-F) to either immobilization (studies=8, n=399 shoulders) or arthroscopic Bankart repair following recurrent dislocations (ABR-R) (studies=8, n=943 shoulder). Mean follow-up was 59.4±39.2 months across all studies. Cumulative loss to follow-up was 4.7% (range, 0%-32.7%). A composite rate of pooled re-dislocation, cumulative instability and re-operations across ABR-F studies was 6.8%, 11.2% and 6.1%, respectively. Meta-analysis found statistically significant reductions in rates of re-dislocation (OR 0.09, 95%CI 0.04-0.3, p=0.00), cumulative instability (OR 0.05, 95%CI 0.03-0.08, p=0.00), and subsequent surgery (OR 0.08, 95%CI 0.04-0.15, p=0.00) when comparing ABR-F to immobilization. Rates of cumulative instability (OR 0.32, 95%CI 0.22-0.47, p=0.00) and subsequent surgery rates (OR 0.27, 95%CI 0.09-0.76, p=0.01) were significantly reduced with ABR-F relative to ABR-R, with point estimate of effect favoring ABR-F for shoulder re-dislocation rates (OR 0.59, 95%CI 0.19-1.83, p=0.36). RTS rates to preoperative levels or higher were 3.87 times higher following ABR-F compared to immobilization (95%CI 1.57-9.52, p=0.00), with limited ABR-R studies reporting this outcome. The median fragility index of the five included RCTs was 2 meaning reversing only 2 outcome events rendered the trials findings no longer statistically significant. Conclusion Arthroscopic stabilization surgery for FTASDs leads to lower rates of re-dislocations, cumulative instability, and subsequent stabilization surgery relative to immobilization or arthroscopic stabilization surgery following recurrence. While a limited number of RCTs have been published on the subject matter to date, the strength of their conclusions is limited by a small sample size and statistically fragile results.