A tear in the anterior cruciate ligament (ACL) is one of the most common knee injuries. An injury to this ligament causes the knee to become unstable and the joint to slide forward too much. ACL tears occur most often in athletes.
ACL reconstruction is usually not performed until several weeks after the injury, when swelling and inflammation have been reduced. The torn ligament is completely removed and replaced with a new ACL. Simply reconnecting the torn ends will not repair the ACL. Part of another ligament, usually in the knee or hamstring is used to create a graft for the new ACL. Choosing the proper type of graft depends on each patient's individual condition.