ANTERIOR CRUCIATE LIGAMENT (ACL) INJURY

The ACL, one of four main ligaments that stabilize the tibia to the femur, runs diagonally through the center of the knee and controls anterior translation and rotational movement within the knee.

Cause

ACL injuries generally happen to active people, particularly athletes. The mechanism often involves a sudden deceleration and rotational motion such as cutting or sidestepping maneuvers. An awkward off-balance landing or "out of control" play can also contribute to injury. Several investigational studies have shown that female athletes injure the ACL more frequently than males, particularly in jumping and cutting sports like basketball and soccer. Up to 50% of ACL tears may have associated injuries to the articular cartilage, meniscus or other ligaments. An MRI scan is useful to confirm a tear of the ACL, as well as to identify additional injuries that may impact treatment recommendations and long-term outcome.

Prevention

Neuromuscular training to improve balance, joint position sense (proprioception) and muscle strength can reduce the incidence of ACL injuries. This is particularly true for female athletes. Core strengthening of the trunk and hips is a key component of this kind of preventative training.

Treatment

Some patients without ongoing symptoms of instability and those who are not highly active may respond well to non-operative treatment of ACL injuries. Through physical therapy and independent exercises to enhance proprioception and strength, some patients can learn to control instability. A functional hinged brace may be used as well. However, several studies have shown that chronically ACL deficient patients are more likely to sustain new mensical injuries over time. Surgical reconstruction is generally recommended for active individuals with ongoing symptoms of instability and when combined injuries to the meniscus, articular cartilage or other ligaments are present.

A torn ACL cannot be repaired but must be reconstructed. There are several options regarding the type of tissue that can be used to reconstruct the ACL. This decision should be made in consultation with an orthopedic specialist. Modern ACL surgery has a high success rate for restoring stability and function to the knee. The post-operative rehabilitation process is a very important part of reaching full potential. This process generally takes from six months to a year.