Anterior cruciate ligament (ACL) injuries are common injuries that occur throughout high school, collegiate, and professional sports. The majority of these injuries occur without contact and disproportionately impact female athletes. Females are 3 to 4 times more likely to tear their ACL in a noncontact scenario than males.[1] The reason behind this difference is an active area of research but is likely due to many factors. Furthermore, these injuries can develop into lifelong debilitations such as osteoarthritis that can diminish a person’s quality of life.[6] It is important to understand the reasons why these injuries occur and develop strategies to prevent them.
The knee joint is constructed of the femur (thigh) and tibia (shin). It is supported by many ligaments that connect the thigh bone to the shin bone. The ACL sits in the middle of the knee and crosses from the back to the front of the knee. The main role of the ACL to prevent the shin bone from moving too far forward.
Movement of the knee is mostly caused by the hamstrings on the back of the thigh and the quadriceps on the front of the thigh. The quadriceps will make the knee go straight (extend) and the hamstrings will bend the knee (flex).
Noncontact ACL injuries most often occur when an athlete slows down, pivots while running, and land from a jump.[2],[4],[5] These types of movements are quite common in sports, especially in soccer, basketball, and football. There have been many studies that use film review and modeling techniques to understand how the ACL tears during these movements. It is generally thought the most noncontact ACL injuries occur when the knee bows inward and then twists.[2],[4],[5] This appears to put enough stress on the ACL to tear it. The ACL can also tear when an athlete lands from a jump and the knee bows inward.[2],[4],[5]
There is no sure-fire way to prevent ACL tears and sometimes people just have bad luck. However, there are some training programs aimed at preventing tears by increasing lower extremity strength, flexibility, and fine motor control.[3] Additionally, many programs will teach proper jumping and landing techniques while utilizing plyometric training to enhance athletic performance during common maneuvers that tear the ACL.[3]
If an ACL tear is suspected, ice and immobilization should be used immediately. An evaluation should then be performed by a sports medicine physician or orthopedic surgeon. An MRI may be needed to assess the degree of damage to the knee.[7] Your orthopedic surgeon will then recommend the best treatment options for you. Surgery may be necessary to repair the damage to the ACL. Depending on your injury, surgery may be an outpatient or overnight procedure.[7] The exact recovery times will vary between patients, injury, and procedure type. Any concerns and your specific treatment goals should be discussed with your surgeon.
ACL injuries can be a debilitating and costly injury to athletes and individuals. It can take individuals and athletes off their feet for several months and may require surgery to repair. Prevention revolves around strength and flexibility training to develop proper techniques. Any individual or athlete with an ACL tear should talk to their surgeon about their treatment goals so that their physicians can get them set up on the right treatment and rehabilitation track.
