Epidemiology of Patellofemoral Injuries in Collegiate Athletes in the United States from 2009-2014
As many as 30% of knee injuries seen in sports medicine clinics are of patellofemoral origin; however, the studies that report on such injuries often refer to generalized patellar tendinopathy and do not specify injury type. As such, there is a paucity of literature examining the epidemiology of specific patellofemoral injuries. The purpose of this study was to determine the incidence of patellofemoral injuries, as well as the most common types and mechanisms of these injuries in collegiate athletes across multiple sports.
This study was approved by the NCAA Research Review Board. The data was obtained from the Datalys Center for Sports Injury Research and Prevention, Inc. A reportable injury was defined as any injury that occurred as a result of participation in an organized team practice or competition and required attention from a physician or athletic trainer. An athlete-exposure (AE) was defined as one student-athlete participating in one NCAA-sanctioned practice or competition in which he or she was exposed to the possibility of athletic injury, regardless of the time associated with that participation. Injury rates per 100,000 AEs were calculated with 95% confidence intervals (CI). Rate ratios (RR) and injury proportion ratios (IPR) were calculated to compare injury rates.
Overall, 602 patellofemoral injuries were reported during 3,739,004 AEs across 25 sports, yielding an overall injury incidence rate (IR) of 16.10/100,000 AEs. Women’s volleyball had the highest overall IR of all sports (39.57 per 100,000 AEs), followed by men’s basketball (28.27) and women’s soccer (25.96). Patellofemoral injuries were significantly more likely to occur during competition than practice (IPR = 1.66, 95% CI 1.38-1.98). Men’s football was responsible for the most patellar injuries of any sport, with 141 of the 602 total injuries (23.4%). Men sustained significantly fewer injuries than women in comparable sports (RR, 0.70; 95% CI 0.55-0.89). Patellar tendinitis (49.2%) was the most common type of injury among all collegiate athletes. The majority (65.6%) of injuries resulted in <24 hours of time loss (TL). The mean TL for all injuries was 3.06 days. Injuries that resulted in >24 hours of TL had a mean TL of 10.32 days. The most common mechanisms of injury were Overuse/Gradual (252/602, 41.8%) and No Apparent Contact (184/602, 30.6%). Surgery was required for 26 (5.1%) patellofemoral injuries, with patellar fractures being most likely to receive such treatment (80.0%).
Patellofemoral injuries are relatively common in collegiate athletes; however, the majority of injuries result in <24 hours of TL from sport participation. Women’s volleyball, men’s basketball, and women’s soccer sustained the highest rates of patellofemoral injuries over the 5-year study period. Furthermore, female athletes experience patellofemoral injuries at a greater rate than males. The development of prevention programs targeting jumping/cutting sports, especially in females, may decrease the incidence of patellofemoral injuries in collegiate athletes.