Postoperative Complications Following Shoulder Stabilization for Primary Versus Recurrent Anterior Shoulder Dislocation: A National Database Study.

BACKGROUND: Anterior shoulder dislocation (ASD) is the most common joint dislocation in young patients with recurrence rates of nearly 90%. Multiple dislocations can cause progressive structural damage and bone loss, increasing the risk of instability. This study compares recurrence and postoperative complications following ASD between patients with a primary versus recurrent ASD. We hypothesized that surgical stabilization following recurrent ASD would be associated with an increased risk of subsequent instability and a higher complication burden.

METHODS: A retrospective query was conducted using the TriNetX database (January 1, 2015 to January 1, 2025) in accordance with STROBE/RECORD guidelines. Patients aged 18 years or older undergoing surgical repair for primary or recurrent ASD were identified. Propensity score matching was applied in a 1:1 ratio and estimated using logistic regression. Postoperative outcomes were evaluated at 3 and 6 months with Benjamini-Hochberg false discovery rate correction (q=0.05) applied to cohort comparisons. Multivariate logistic regression analysis was performed to assess independent risk factors.

RESULTS: Pre-match cohorts included 2,312 patients who underwent surgical repair for primary ASD compared to 7,594 patients in the recurrent ASD cohort; propensity score matching yielded 2,302 patients per group (mean age: 29.7±14.5 years vs. 28.8±13.6 years, respectively). Following Benjamini-Hochberg false discovery rate correction, recurrent ASD patients experienced significantly higher rates of subsequent dislocation (3-month: 21.4% vs. 1.3%, RD=-20.1%; 6-month: 23.5% vs. 1.7%, RD=-21.8%; both p<0.0001) and shoulder instability (3-month: 44.0% vs. 21.8%, RD=-22.2%; 6-month: 47.8% vs. 24.0%, RD=-23.8%; both p<0.0001). At 6-months, reoperation rates differed between cohorts on unadjusted analysis (2.0% vs. 1.1%, RD=-0.9%, p=0.0159), but the difference did not retain significance following Benjamini-Hochberg FDR correction (q=0.089). No significant differences were observed in shoulder stiffness, rotator cuff tears, shoulder impingement, or shoulder pain. Logistic regression analysis demonstrated that elevated BMI significantly increased odds of postoperative shoulder instability at 3 and 6 months (p=0.022-0.038) in both the primary and recurrent ASD groups. Epilepsy or recurrent seizures were significantly associated with postoperative instability across both time points in primary and recurrent repair groups (p<0.01).

CONCLUSION: Patients undergoing surgical repair for recurrent ASD experienced significantly higher short-term rates of recurrent instability compared to those treated for primary ASD. Elevated BMI and seizure disorders were identified as independent risk factors associated with postoperative instability. These findings should be interpreted as associative and hypothesis-generating. Prospective cohort studies incorporating granular imaging and procedure-level data are needed to validate these relationships and evaluate whether surgical selection modifies recurrence risk in high-risk patients.

LEVEL OF EVIDENCE: Level III, Retrospective Cohort Comparison using Large Database, Prognosis Study.