Indications for Isolated Arthroscopic Bankart Repair in the Adolescent Shoulder May Be Limited: Bipolar Bone Loss and Low Distance to Dislocation Found Commonly in an Adolescent Population With Glenohumeral Instability

Background: Bone loss is an established risk factor for recurrent anterior shoulder instability and failure of isolated arthroscopic Bankart repair; however, its prevalence and clinical significance at initial presentation in adolescents remains poorly characterized. Purpose/Hypothesis: The purpose of this study was to evaluate the prevalence of bone loss and the factors that correlate with bipolar bone loss in adolescent patients evaluated with anterior shoulder instability. It was hypothesized that male sex, older age, higher number of dislocations, and contact sports participation would be associated with bipolar bone loss at initial presentation. Study Design: Cohort study; Level of evidence, 3. Methods: A retrospective institutional review board–approved study of 181 patients aged 10 to 19 years diagnosed with anterior shoulder instability from January 2022 to March 2024 was performed at a single tertiary referral center. Glenoid bone loss, Hill-Sachs interval, on-track versus off-track status, and distance to dislocation (DTD) were measured on magnetic resonance imaging. The association between bipolar bone loss and patient characteristics, sports participation, and prior dislocation history was evaluated using chi-square and Mann-Whitney U tests with univariate and multivariate logistic regression. Results: Overall, 74.6% of patients exhibited bone loss; 34.3% had bipolar bone loss, 7.2% were off-track, and 41.4% had a DTD <10 mm. Among those with first-time dislocation, 69.2% presented with bone loss and 37.4% had a DTD <10 mm. Bipolar bone loss was significantly associated with older age (16.29 vs 15.61 years; P = .012), male sex (96.8% vs 69.7%; P < .001), high-impact/collision sports participation (94.6% vs 73.6%; P = .001), and ≥5 prior dislocations (28.8% vs 9.9%; P = .003). On multivariate analysis, male sex (OR, 14.20; P = .011) and ≥5 prior dislocations (OR, 3.22; P = .026) were independent predictors of bipolar bone loss. Conclusion: One-third of adolescents in our series presenting with anterior shoulder instability had bipolar bone loss at the initial evaluation, with male sex and ≥5 prior dislocations as independent predictors. The high prevalence of off-track lesions and DTD <10 mm suggests that isolated Bankart repair may be insufficient for many adolescent patients.