Single anterior shoulder dislocation patients demonstrate higher rates of posterior labral repair and biceps procedures than multiple dislocators at the time of arthroscopic stabilization surgery.

Hypothesis: The purpose of this study is to identify and compare demographic, clinical, historical, and intraoperative variables in patients who have received arthroscopic treatment for single vs. multiple anterior shoulder dislocations. Methods: This is a retrospective chart review of patients who underwent arthroscopic labral repair of the shoulder by six surgeons at a single institution between 2012 and 2020. Patients with a documented anterior shoulder dislocation were included. Patients with pain-only, subluxation-only, multidirectional or posterior instability, and prior shoulder surgeries of any kind were excluded. Studied variables included age, sex, laterality, body mass index, contact/collision sports, Charlson comorbidity index, tobacco use, number of dislocations (1, >1), labral tear size, time from first dislocation to surgery, anchor number, and concomitant procedures. Study groups were compared using student's t-tests and Mann-Whitney U test for continuous variables and chi-square or Fisher's exact tests for discrete variables with a significance of 0.05. Results: Six hundred thirty-three patients were identified, and 351 (85 single dislocators [SDs], 266 multiple dislocators [MDs]) met inclusion criteria (mean age: 27 years; range: 14-71 years). There were no demographic differences between the study groups. SD received surgery significantly sooner at 17 ± 44 months after injury, while MD received surgery 53 ± 74 months postinitial dislocation. SDs (30/85, 35%) were significantly more likely than MDs (56/266, 21%) to receive concomitant posterior labrum repair. MDs (46/266, 17%) were significantly more likely than SDs (5/85, 6%) to receive a remplissage. SDs (11/85, 13%) were significantly more likely than MDs (11/266, 4%) to receive a concomitant biceps tenotomy/tenodesis. There were no other significant differences in injury or surgery characteristics. Conclusion: MDs will have more time between their initial dislocation and arthroscopic labral repair and are more likely to receive a remplissage procedure, yet they are less likely than SDs to receive a concomitant posterior labral repair or biceps tenodesis/tenotomy despite no differences in age, sex, and activity level. Whether the greater extent of labrum injury in SD is due to a more severe initial injury vs. earlier recognition and intervention requires further study.