Arthroscopic Bankart Repair for Adolescent Anterior Shoulder Instability: Clinical and Imaging Predictors of Revision Surgery and Recurrent Subjective Instability

Background: Multiple clinical and radiologic risk factors for recurrent instability after arthroscopic Bankart repair have been described. Humeral bone loss has gained more recent attention, particularly with respect to “off-track” lesions and increased rates of recurrent instability and revision surgery. Purpose: To evaluate clinical and radiologic predictors of failure after arthroscopic Bankart repair in adolescents. Study Design: Case series; Level of evidence, 4. Methods: A single-institution retrospective study was performed in patients <19 years of age treated with arthroscopic Bankart repair from 2011 to 2017. Magnetic resonance imaging measurements of glenoid and humeral bone loss, the glenoid track, and the presence of off-track Hill-Sachs (HS) lesions were assessed. All patients had a minimum follow-up of 24 months and completed patient-reported outcome scores. Failure was defined as revision surgery or postoperative subjective instability. Results: A total of 59 patients (46 male, 13 female) with a median age of 16 years (range, 12-18 years) were included. Ten patients (17%) had revision surgery and 8 patients (14%) had subjective instability without revision surgery. No clinical or radiologic factors were significantly different between the failure cohort and the nonfailure cohort. Four patients (7%) measured off-track, and 2 of these patients experienced failure. A total of 38 patients (64%) were identified to have an HS defect. Subgroup analysis of these patients identified a greater HS interval (HSI) in patients who underwent revision surgery as compared with those patients who did not have revision surgery. Among patients with GT ratio ≥15 mm, there was a 50% rate of revision surgery. The Pediatric/Adolescent Shoulder Survey (PASS) and Single Assessment Numeric Evaluation (SANE) scores at the final follow-up were not significantly different among patients with or without revision surgery. However, those with subjective instability who had not undergone revision surgery had significantly lower PASS and SANE scores as compared with the remainder of the cohort. Conclusion: Of the adolescents in this cohort, 31% either had revision surgery (17%) or reported subjective feelings of instability (14%) after arthroscopic Bankart repair. Off-track instability was identified in 7% of the cohort but was not predictive of failure. Among the subgroup of patients with an HS defect, those who underwent revision surgery had a significantly larger HSI.