Atypical Shoulder Instability Patterns in Adolescents Following Traumatic Anterior Shoulder Dislocation

Background: Traumatic anterior shoulder instability is common in the adolescent athlete, and when it is untreated, the recurrence rate is high. Atypical lesions—such as anterior glenoid periosteal sleeve, humeral glenohumeral ligament, and insertional tendon avulsions—may occur within this population, and accurate diagnosis and appropriate lesion management are key to treatment success. Purpose: To evaluate the age, skeletal immaturity, bone loss, and uncommon soft tissue lesions as correlates of posttraumatic anterior shoulder instability lesion patterns in an adolescent population. Study Design: Cross-sectional study, Level of evidence, 3. Methods: Consecutive patients ≤18 years of age (160 shoulders) treated within a single institution for traumatic anterior shoulder instability between June 2013 and June 2021 were reviewed. Demographics, injury mechanism, radiographic and magnetic resonance imaging of lesions, the presence of any bone loss, operative findings, and physeal status were recorded. An overall 131 shoulders met the inclusion criteria. Instability lesion type was analyzed categorically by age <15 or ≥15 years; individual age was assessed for correlation with any bone loss present. Atypical lesions—anterior labral periosteal sleeve avulsion, humeral avulsion of the glenohumeral ligament, subscapularis avulsion—were assessed for correlations with age, open physeal status, and the presence of any bone loss. Results: An overall 131 shoulders (mean, 15.3 years; range, 10.5-18.3) were identified for this study: 55 in patients <15 years old and 76 in patients ≥15 years old. Bony injuries such as Bankart and Hill-Sachs lesions were more common in the ≥15-year-old group (P =.044 and P =.024, respectively). Bony Bankart injuries were found at a rate of 18.2% in the <15-year-old group, as compared with 34.2% in the ≥15-year-old group (P <.05). Anterior labral periosteal sleeve avulsions were more common in the <15-year-old group (n = 13 [23.6%] vs n = 8 [10.5%]; P <.044), as were all atypical lesions combined (n = 23 [41.8%] vs n = 13 [17.1%]; P <.0018]. Conclusion: In this series of anterior shoulder instability in children and adolescents, instability lesions varied significantly by age. Bone loss was associated with older age at presentation, and atypical lesions were more common in patients <15 years of age. Treatment teams should be aware of less common soft tissue injuries in this young age group and ensure careful review of adequate imaging for proper diagnosis and treatment in these younger patients.