Pain, especially when you try to put weight on the injured leg
Those who have only a mild injury may notice that the knee feels unstable or seems to "give way" when using it.
See your health care provider if you think you have an ACL injury. Do not play sports or other activities until you have seen a doctor and been treated.
Your doctor may send you for an MRI of the knee. This can confirm the diagnosis. It may also show other knee injuries.
First aid for an ACL injury may include:
Raising your leg above the level of the heart
Putting ice on the knee
Pain relievers such as nonsteroidal anti-inflammatory drugs (such as ibuprofen)
You may need:
Crutches to walk until the swelling and pain get better
Physical therapy to help improve joint motion and leg strength
Surgery to rebuild the ACL
Some people can live and function normally with a torn ACL. However, most people complain that their knee is unstable and may "give out" with physical activity. Unrepaired ACL tears can lead to further knee damage.
Do NOT move your knee if you have had a serious injury.
Use a splint to keep the knee straight until you see a doctor.
Do NOT return to play or other activities until you have been treated.
Call immediately for emergency medical assistance if
Anyone with a serious knee injury should seek medical attention for x-rays and evaluation.
If the foot is cool and blue after a knee injury, the knee joint may be dislocated, and blood vessels to the foot may be injured. This is a medical emergency that requires immediate professional help.
Use proper techniques when playing sports or exercising. Some college sports programs teach athletes how to reduce stress placed on the ACL.
The use of knee braces during aggressive athletic activity (such as football) is controversial, and has not been shown to reduce the number of knee injuries.
Griffin LY, Armstrong A, DeMaio M. The female athlete. In: DeLee JC, Drez D Jr, Miller MD, eds. DeLee and Drez’s Orthopaedic Sports Medicine. 3rd ed. Philadelphia, Pa: Saunders Elsevier; 2009:chap 10.
Honkamp NJ, Shen W, Okeke N, Ferretti M, Fu FH. Anterior cruciate ligament injuries: 1. Anterior cruciate ligament injuries in the adult. In: DeLee JC, Drez D Jr, Miller MD, eds. DeLee and Drez’s Orthopaedic Sports Medicine. 3rd ed. Philadelphia, Pa: Saunders Elsevier; 2009:chap 23, section D.
Cimino F, Volk BS, Setter D. Anterior cruciate ligament injury: diagnosis, management, and prevention. Am Fam Physician. 2010;82:917-922.
Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; C. Benjamin Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.