Which athletes are at greatest risk for tearing the anterior cruciate ligament (ACL)? Athletes who play basketball, football, rugby, soccer, field hockey or ultimate Frisbee? Are college athletes at greater risk than high school athletes?
These questions were recently answered by the sports medicine trauma research group the University Of Vermont Department Of Orthopedic Surgery. The publication appeared in the American Journal of Sports Medicine and was titled “The Effects of Level of Competition, Sport, and Sex on the Incidence of First-Time Noncontact Anterior Cruciate Ligament Injury.”
The research group investigated Vermont high school and college athletes between the years of 2008 and 2012 who played running and cutting sports like football, soccer, lacrosse and basketball. The injured athletes tore their ACL with a plant and twist type motion. In all cases, no direct impact occurred at the knee of the injured athlete. What we found:
- The colleges reported 48 injuries in over 300,000 games or practices and high schools reported 55 in nearly 900,000.
- Female athletes suffered a total of 59 ACL tears in over 500,000 games or scrimmages and males’ 42 injuries in nearly 700,000.
- In general, college athletes were 2.3 times more likely of tearing their ACL than high school athletes and females 2.1 times more likely than males to suffer an ACL tear.
- The sports at greatest risk for injury were rugby and soccer.
Is tearing the ACL an epidemic in sports? I think it comes down to how one wants to look at the question. I have surgically reconstructed the ACL on an entire starting lineup of a high school girls’ basketball team in Texas. I think it was an epidemic for that team. If we look at the possibility of injuring the ACL as 1 in 100,000 athletic events then it may not be so bad. If one stratifies athletic events as game and heavy scrimmages, but does not include light practices or drill, then the cumulative incidence in rather low. Even after many years of playing a sport, the injury risk remains low if the exposure to serious injury remains low by controlling and/or limiting aggressive game and scrimmage activities. Therefore, some of the risk for injury is simply a numbers game. Those who get injured are those who play more games and play more frequently.
However, many athletes do not tear their ACL and many play multiple sports and play in many scrimmages and games. Why is this true? Different sports and different athletes all have different risk for injury. Some variances in ACL injury are related to the environment, family history of ACL injury, athlete’s knee and body geometry and the person’s sex. Known risk factors for ACL injury are the female sex, greater BMI (tall and heavy athletes), generalized loosed joints, loose knees, and several anatomic knee specific measurements (narrow intercondlar notch, smaller sized ACL, and a more angled tibia plateau). Probably the most significant risk factor for suffering and ACL injury is having a parent with an ACL injury!
Some of the injury risk can be countered by taking adequate rest to allow the body to repair itself, undertaking reasonable risk exposure and participating in an approved injury prevention performance enhancement program (PEP or FIFA 11 +). Injury prevention and performance enhancement is the most significant way to prevent injury in high school, college, and professional athletes. Both of these programs have a wealth of information available demonstrating the programs ability to sufficiently decrease ACL, knee, ankle, and hip injuries.
ACL injuries are commonly seen in high school and college athletes participating in at-risk sports. Injury risk can be identified and injury prevention programs can be incorporated to decrease risk and increase performance.
James Slauterbeck, MD, is an orthopedic surgeon at the University of Vermont Medical Center and associate professor at the Larner College of Medicine at UVM.