Epidemiology of Acute Extensor Mechanism Injuries in Collegiate-Level Athletes in the United States

Kevin K. Chen, Jimmy J. Chan, William Ranson, Nicholas Debellis, Hsin Hui Huang, Ettore Vulcano, Alexis Colvin

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


Background: Extensor mechanism injuries involving the quadriceps tendon, patella, or patellar tendon can be a devastating setback for athletes. Despite the potential severity and relative frequency with which these injuries occur, large-scale epidemiological data on collegiate-level athletes are lacking. Study Design: Descriptive epidemiology study. Level of Evidence: Level 4. Methods: Knee extensor mechanism injuries across 16 sports among National Collegiate Athletic Association (NCAA) men and women during the 2004-2005 to 2013-2014 academic years were analyzed using the NCAA Injury Surveillance Program (NCAA-ISP). Extensor mechanism injuries per 100,000 athlete-exposures (AEs), operative rate, annual injury and reinjury rates, in-season status (pre-/regular/postseason), and time lost were compiled and calculated. Results: A total of 11,778,265 AEs were identified and included in the study. Overall, 1,748 extensor mechanism injuries were identified, with an injury rate (IR) of 14.84 (per 100,000 AEs). N = 114 (6.5%) injuries were classified as severe injuries with a relatively higher median time loss (44 days) and operative risk (18.42%). Male athletes had higher risk of season-ending injuries in both all (3.20% vs 0.89%, P < 0.01) and severe (41.54% vs 16.33%, P < 0.01) extensor mechanism injuries. Similarly, contact injuries were more frequently season-ending injuries (4.44% vs 1.69%, P = 0.01). Women’s soccer (IR = 2.59), women’s field hockey (IR = 2.15), and women’s cross country (IR = 2.14) were the sports with the highest rate of severe extensor mechanism injuries. Conclusion: Extensor mechanism injuries in collegiate athletes represent a significant set of injuries both in terms of volume and potentially to their athletic careers. Male athletes and contact injuries appear to have a greater risk of severe injuries. Injuries defined as severe had a higher risk of operative intervention and greater amount of missed playing time. Clinical Relevance: Knowledge of the epidemiology of extensor mechanism injuries may help clinicians guide their athlete patients in sports-related injury prevention and management.

Original languageEnglish
Pages (from-to)262-272
Number of pages11
JournalSports Health
Issue number2
StatePublished - Mar 2022


  • NCAA injuries
  • extensor mechanism injury
  • patella fracture
  • patella tendon rupture
  • quadriceps tendon rupture


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