ACL Tear

Signs and Symptoms

The anterior cruciate ligament is one of the two cross-shaped (cruciate) ligaments located within the knee joint and which cross over each other as they run diagonally between the thigh and leg bones, providing additional support, preventing overbending and overstraightening of the knee, and limiting sliding movement between the bones.

Symptoms include:

• There may be an audible pop at a moment of injury.
• Your knee tends to slip out of joint, feels unstable, and swelling and pain hinder movement.
• Your knee often feels as though it will give way or is unstable.

Diagnosis

Your doctor may conduct physical tests and take X-rays to determine the extent of damage to your ACL. Most of the time, you will need reconstruction surgery.

Treatment

Only about a third of people with a completely torn ACL are able to build their muscle strength enough to resume normal activities without surgery. Still, the non-operative option exists, and having surgery or forgoing it is partly a personal choice.

Those who are not very active may choose a strengthening program instead of surgery, since the injury is not likely to interfere with their daily activities. Such a program takes about six to 10 months to complete. However, about 65 percent of all patients with a torn ACL will eventually develop a torn meniscus — a protective cartilage that reduces friction between the knee bones — which may predispose them to early onset arthritis.

Active, athletic people are more likely to opt for surgery, so that the knee can be repaired and rehabilitated and they can return to their activities.

The surgery is called an endoscopic ACL reconstruction and is done using small instruments through a Band-Aid size incision. It is done either on an outpatient basis or you may have to spend the night in the hospital. After four to six months, you should be able to return to unrestricted activity and competitive sports.

Hear a Patient Power segment on ACL injuries featuring UCSF orthopedic surgeon Dr. Christina Allen.