Epidemiology of Shoulder Instability Injuries in Collision Collegiate Sports From 2009 to 2014

Purpose: To describe the types, mechanisms, and severity of shoulder instability injuries in collegiate collision athletes during the 2009-2010 through 2013-2014 academic years using the National Collegiate Athletic Association Injury Surveillance Program; to compare the injury incidence between men's collision sports and their women's non-collision counterparts, when possible; and to compare injury outcomes between Divisions I, II, and III. Methods: Data regarding men's football, wrestling, ice hockey, and lacrosse, as well as women's ice hockey and lacrosse, were obtained. Injuries requiring attention from a health care provider were reported. Incidence rates per 100,000 athlete-exposures (AEs) were calculated with 95% confidence intervals (CIs). Analysis of variance was used to compare time loss (TL), and chi(2) analysis was used to compare surgery rates between divisions. Results: A total of 445 shoulder instability injuries occurred in 1,421,561 AEs from 2009-2010 to 2013-2014 (incidence rate, 31.30 injuries/100,000 AEs; 95% CI, 28.4-34.21 injuries/100,000 AEs). Subluxation accounted for 59.1% of injuries, with anterior subluxation (35.3%) being the most common injury. Dislocation resulted in the most TL per injury (17.58 days). Mean TL for all injuries was 8.17 days (standard deviation, 7.21 days). When non-time-loss injuries were excluded from analysis, players experienced a mean TL of 18.34 days (standard deviation, 8.44 days). Divisions I (4.77 days), II (20.52 days), and III (11.23 days) differed significantly in mean TL (P = .01). Of the injuries, 29.3% required surgery. The surgery rates for Divisions I (32.9%), II (38.1%), and III (19.4%) also differed significantly (P = .04). Men's ice hockey and lacrosse players sustained a 2.17-fold (95% CI, 1.04-4.50) higher incidence of shoulder instability than their female counterparts. Conclusions: Anterior subluxation and dislocation accounted for 52.1% of all shoulder instability injuries. Injured athletes missed 8 days on average, and nearly 30% of injuries required surgery. Surgery rates and TL were significantly different between Divisions I, II, and III. Female athletes playing non-collision ice hockey and lacrosse experienced significantly lower shoulder instability rates than their male counterparts.