Anterior Cruciate Ligament Tear

The anterior cruciate ligament is a ligament in the knee that provides translational and rotational stability to the knee. Tears of the ACL often occur during sports activities as a result of a sudden twisting or contact injury. Patients often feel or hear a pop in the knee when the ligament tears. Swelling is common and usually is noticeable within an hour of injury. Initial treatment consists of ice, rest, crutches, analgesic medication, and therapy to help restore normal knee motion. An MRI can confirm the diagnosis and can assess for other pathology such as tears of the menisci and injuries to the articular cartilage and other ligaments.

Arthroscopic image of an acute ACL tear

A chronic ACL tear can result in knee instability and patient often experience “give way” episodes with activities. Pathologic knee laxity can lead to arthritis in the knee if not adequately treated.

Surgery is offered to patients with knee instability and persistent symptoms. The surgery is an ACL reconstruction, which is using a tendon graft to “make a new” ligament. Tendon grafts can be obtained from other areas on the patient’s knee, including a portion of the patellar tendon, quadriceps tendon, or hamstring tendons. A allograft (cadaveric) ligament can also be used, although the results of allograft ACL reconstruction are not as good or predictable as using one’s own tissue.

Arthroscopic image of an ACL reconstruction with a patellar tendon graft

Watch a video of a knee arthroscopy with ACL reconstruction.