Male Sex, Western Ontario Shoulder Instability Index Score, and Sport as Predictors of Large Labral Tears of the Shoulder: A Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Instability Cohort Study

Purpose: To identify factors predictive of a large labral tear at the time of shoulder instability surgery. Methods: As part of the Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Instability cohort, patients undergoing open or arthroscopic shoulder instability surgery for a labral tear were evaluated. Patients with >270° tears were defined as having large labral tears. To build a predictive logistic regression model for large tears, the Feasible Solutions Algorithm was used to add significant interaction effects. Results: After applying exclusion criteria, 1235 patients were available for analysis. There were 222 females (18.0%) and 1013 males (82.0%) in the cohort, with an average age of 24.7 years (range 12 to 66). The prevalence of large tears was 4.6% (n = 57), with the average tear size being 141.9°. Males accounted for significantly more of the large tears seen in the cohort (94.7%, P =.01). Racquet sports (P =.01), swimming (P =.02), softball (P =.05), skiing (P =.04), and golf (P =.04) were all associated with large labral tears, as was a higher Western Ontario Shoulder Instability Index (WOSI; P =.01). Age, race, history of dislocation, and injury during sport were not associated with having a larger tear. Using our predictive logistic regression model for large tears, patients with a larger body mass index (BMI) who played contact sports were also more likely to have large tears (P =.007). Conclusions: Multiple factors were identified as being associated with large labral tears at the time of surgery, including male sex, preoperative WOSI score, and participation in certain sports including racquet sports, softball, skiing, swimming, and golf. Level of Evidence: I, prognostic study.