Combining Instability Severity Index Score and Hill‐Sachs Interval‐to‐Glenoid Track Ratio Predicts Recurrent Instability After Arthroscopic Bankart Repair in Patients With <20% Glenoid Bone Loss

PURPOSE: To further investigate predictors of recurrence after arthroscopic Bankart repair (ABR) and to assess postoperative function in patients with and without recurrence. METHODS: A retrospective review was conducted on patients aged 14 to 50 years who underwent ABR for anteroinferior glenohumeral instability between 2009 and 2021. All patients had a minimum follow-up of 3 years. Clinical and radiological data were extracted and analyzed. Cox regression models identified independent predictors of recurrence, and receiver operating characteristic curves evaluated the predictive performance of individual and combined indicators. Patient-reported outcomes, including the American Shoulder and Elbow Surgeons score, Rowe score, and Single Assessment Numerical Evaluation score, were assessed. RESULTS: A total of 264 patients (241 males) with a mean age of 25.6 ± 7.1 years and a mean follow-up 93.7 ± 36.7 months were included. Recurrent instability occurred in 38 patients (14.4%). Multivariate Cox regression analysis identified the Instability Severity Index Score and the Hill-Sachs interval-to-glenoid track ratio as independent predictors of recurrence. The integration of these 2 indicators into a binary logistic regression model yielded a composite score that significantly improved predictive performance (area under the curve = 0.81 vs Instability Severity Index Score = 0.76, Hill-Sachs interval-to-glenoid = 0.77; all P < .05). At the final follow-up, all patients achieved the minimal clinically significant difference, and patients without recurrence exhibited superior patient-reported outcomes (all P < .05) compared to those with recurrent instability. CONCLUSIONS: The Instability Severity Index Score and the Hill-Sachs interval-to-glenoid track ratio composite score showed good predictive performance for recurrence after ABR. It stratified patients into distinct treatment categories: (1) ABR for low-risk patients (score < 3.4), (2) alternative stabilization procedures for high-risk patients (score > 5.5), and (3) individualized clinical evaluation and shared decision-making for intermediate-risk patients (score 3.4-5.5). Additionally, shoulder function in patients undergoing revision surgery due to recurrence was worse than in those without recurrence. LEVEL OF EVIDENCE: Level III, retrospective prognostic case series.