An anterior cruciate ligament (ACL) injury is a tear in the ACL ligament. The ACL is located in the middle of the knee joint. It connects the lower leg bone to the thigh bone. It stabilizes the knee and prevents the lower leg bone from sliding too far forward at the knee.
The ACL ligament can become strained or torn when a strong force is applied to it. This can happen during sports or other high-stress activity.
Treatment depends on the severity of the injury.
ACL injury occurs when your knee gets twisted or during a hard landing from a jump. It can also happen with:
ACL injuries are more common in women. Other factors that increase your chance of ACL injury include:
Symptoms may include:
The doctor will ask about your symptoms and how you injured your knee. A physical exam will be done.
Tests may include:
Ligament sprains are graded according to their severity:
Talk with your doctor about the best treatment plan for you. Recovery time ranges depending on the grade of your injury. Treatment steps may include:
Your ligament will need time to heal. Avoid activities that place extra stress on the knee:
Your doctor may recommend a knee brace to stabilize the knee, and crutches to keep extra weight off your leg.
Apply an ice or a cold pack to the area for 15-20 minutes, four times a day, for several days after the injury. Do not apply the ice directly to your skin. Wrap the ice or cold pack in a towel.
To manage pain, your doctor may recommend:
Compression can help prevent more swelling. Your doctor may recommend an elastic compression bandage around your knee. Be careful not to wrap the bandage too tight.
Use heat only when you are returning to physical activity. Heat may then be used before stretching or getting ready to play sports to help loosen the ligament.
When the acute pain is gone, start gentle stretching as recommended. Stay within pain limits. Hold each stretch for about 10 seconds and repeat six times. Stretch several times a day.
To reduce your chance of injuring the ACL, take these steps:
American Academy of Orthopaedic Surgeons
American Orthopaedic Society for Sports Medicine
Canadian Orthopaedic Association
Canadian Orthopaedic Foundation
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ACL Injury: Does It Require Surgery? American Academy of Orthopaedic Surgeons website. Available at: http://orthoinfo.aaos.org/topic.cfm?topic=A00297http://orthoinfo.aaos.org/topic.cfm?topic=A00297. Updated September 2009. Accessed May 3, 2013.
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Ligament injuries to the knee. John Hopkins Medicine website. Available at. http://www.hopkinsmedicine.org/healthlibrary/conditions/adult/orthopaedic_disorders/ligament_injuries_to_the_knee_85,P00926/. Accessed May 3, 2013.
7/6/2009 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed/what.php: Prodromos CC, Han Y, et al. A meta-analysis of the incidence of anterior cruciate ligament tears as a function of gender, sport, and a knee injury-reduction regimen. Arthroscopy. 2007;23:1320-1325.
Last reviewed March 2013 by John C. Keel, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.