An anterior cruciate ligament (ACL) tear is an injury of the knee joint. It causes leg pain and instability of the knee. ACL tears are common sports injuries. The ACL is one of four major knee ligaments that control stability of the knee joint.
Without an intact ACL, participants in sports often complain of symptoms of knee instability. The ACL does not heal itself when completely torn, and, therefore, surgical reconstruction of the ligament is the usual treatment.
Without undergoing surgical reconstruction of the ACL, athletes will typically have a difficult time returning to certain sports. Some activities such as cycling, swimming, and even jogging, may be possible to return to, even at high-performance levels. However, athletic activities that involve cutting, pivoting, and side-to-side movements generally require a functioning anterior cruciate ligament. For this reason, most high-level athletes will undergo ACL reconstruction in order to regain sufficient stability in their knee to allow resumption of athletic activities.