ACL Injury Causes, Symptoms, Treatment, and Prevention

Anterior cruciate ligament (ACL) injury is a fairly common type of knee injury. It occurs when the ACL is stretched or torn because of a sudden twisting motion such as that occurs when the feet are planted one way on the ground and the knees are turned to another. The ACL may also be injured with sudden deceleration or faulty landing maneuver wherein the knee is in a vulnerable position. Injury to the ACL is sometimes called a "sprain."

The ACL is a ligament-a cord-like tissue connecting a bone to another bone-in the knee where it crosses with another ligament called the posterior cruciate ligament (PCL). This is where the cruciate (cross-like) ligaments get their name. The ACL limits the rotation and the forward movement of the tibia (shin bone).

ACL injuries are common in athletes participating in team sports such as football, soccer and basketball. However, according to the National Library of Medicine (NLM), about 70 percent of ACL injuries occur with little or sometimes no contact with another player. The athlete would try to prevent contact with another player, thus, performing a sudden movement, which can injure the ACL. The condition may also occur in non-contact sports such as skiing.

Recent studies have shown that women athletes are more likely to injure their ACL than men. According to the National Institutes of Health, young women are eight to ten times more likely than males to injure the ACL. The reason for this is not fully clear. Experts believe that it may be due to differences in knee anatomy and muscular function.

When ACL injury occurs, the person may hear a popping sound and his or her leg may buckle or "give way" upon attempting to stand. Pain and swelling may also be felt on the injured knee.

Treatment of ACL injury depends on the extent of the damage. In mild ACL injuries, ice pack application and elevating the involved limb can help reduce swelling. The doctor may recommend an exercise program to help strengthen the surrounding muscle. A brace may also be recommended to help protect the injured knee during activity.

For a completely torn ACL, the doctor may recommend surgery to replace the damaged ligament. The doctor would likely suggest physical therapy to help create a rehabilitation program for you. With successful surgery and rehab program, people can return to their normal activities.

Although some ACL injuries cannot be prevented such as that occurs in vehicular accidents, some can be prevented. Knowing which motions cause ACL tearing is necessary to prevent injury. Landing on the balls of the feet, avoiding sudden deceleration and sudden twisting motions may help prevent ACL injuries. Warming up and stretching can also help. Strengthening the muscles surrounding and supporting the knee is also important.

With proper medical treatment and rehabilitation, people who have had ACL injuries can return to their normal daily activities and even sports activities.

References:
Q&A About Knee Problems. National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS). Accessed: December 7, 2009

An Athlete's Nightmare: Tearing the ACL. National Institutes of Health (NIH). Accessed: December 7, 2009