Epidemiology of Patella Instability Injuries in Collegiate Level Athletes in the United States

Objective: Patella instability injuries are often sports-related and occur in young athletes. These injuries severely impact the season and career trajectory of high-level competitors. This is the first large epidemiological study that evaluates these injury events in NCAA athletes. Methods: Patellar instability injuries across 16 sports among NCAA men and women during the 2004-05 to 2013-14 academic years were analyzed using the NCAA Injury Surveillance Program (NCAA-ISP). Patellar instability injuries per 100,000 Athlete-Exposures (AEs), operative rate, annual injury and reinjury rates, in-season status (pre/regular/post-season) and time lost were compiled and calculated. Results: A total of 11,778,265 Athlete-Exposures (AE) were identified and included. 380 patellar instability injuries were identified (Injury Rate IR = 3.23 per 100,000 AEs). 91 (23.95%) were severe injuries with a significantly higher time loss from play (40.5 days) and risk of operative management (50.55%). The most common sports during which a patellar instability event occurred were Women’s Gymnastics (IR=7.87), Soccer (IR=5.83), and Basketball (IR=4.34) and Men’s Wrestling (IR=5.44), Football (IR=4.84), and Soccer (IR=3.06). Male athletes had a statistically significant higher risk of season or career-ending injuries in all patellar instability injuries (3.20% vs 0.89%, p=0.0013). Severe injuries were more likely to result from contact mechanisms (58.24% vs 40.66%). Conclusion: Patella instability injuries have a profound impact on the longevity and sustainability of a collegiate athletes’ career. The risk of recurrence once a patellar injury has occurred is significant and athletes often require surgery. While more female athletes sustained these injuries, male athletes were more likely to require operative management and sustain a season-ending injury.