The ACL, or anterior cruciate ligament, is a very important structure for knee stability. It has many functions in the knee, but the most important are to prevent abnormal shifting and rotation of the joint. Many of us know someone who has torn an ACL, and the injury in young athletes can often kill a season. When I make the diagnosis in my patients, it is often met with tears and many, many questions.
Fortunately, most people who suffer an ACL tear will do well with a surgery to reconstruct the ligament. It takes several months to return from the injury, but athletes are usually able to return to their sport at the same level after rehabilitation.
ACL injuries most commonly occur from “noncontact” events. These include quick changes of direction combined with sudden stopping, landing awkwardly from a jump, or pivoting with the knee nearly fully extended when the foot is planted on the ground. Sometimes, player-to-player contact causes a tear, as well.
Research shows that female athletes may be at higher risk than males for ACL injuries. This seems to be because females may perform actions like cutting, landing, and pivoting in a more knock-kneed position. Other issues may be tightness of the hip and knee joints or weaker hamstrings. All of these findings in the legs of athletes combine to increase risk for injury.
The best treatment for the ACL is to prevent injury to it. Studies show that targeting weak muscles in the hips can help decrease the knock-kneed landing position. We often use specific types of training, like jump routines and learning to pivot properly, to help prevent ACL injuries. Programs like these are more effective when they start young.
It may be optimal to start prevention programs during early adolescence, prior to the development of habits that increase the risk of injury. I recommend preseason screening of athletes to identify young athletes who are at high risk and who would therefore benefit from targeted training. There is no way to completely avoid risk of ACL injuries, but strengthening may be the best way we know to decrease it.