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.
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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:
You will be asked about your symptoms and how you injured your knee. A physical exam will be done.
Your knee will need to be viewed. This can be done with:
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:
The ligament will need time to heal. Supportive care may include:
Over-the-counter or prescription medications may be advised to reduce pain.
A physical therapist will assess the ligament. An exercise program will be created to help recovery and to stretch and strengthen the muscles.
Surgery may be needed to fully restore function of the knee. The decision to have surgery should be made after discussion with your doctor about your athletic needs, age, and related factors.
To reduce your chance of injuring the ACL, take these steps:
American Orthopaedic Society for Sports Medicine
OrthoInfo—American Academy of Orthopaedic Surgeons
Canadian Orthopaedic Association
Canadian Orthopaedic Foundation
Anterior cruciate ligament (ACL) injury. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated February 5, 2015. Accessed March 3, 2015.
Anterior cruciate ligament injuries. American Academy of Orthopaedic Surgeons Ortho Info website. Available at: http://orthoinfo.aaos.org/topic.cfm?topic=A00549. Updated March 2014. Accessed March 3, 2015.
Anterior cruciate ligament injuries: treatment and rehabilitation. Encyclopedia of Sports Medicine and Science website. Available at: http://sportsci.org/encyc/aclinj/aclinj.html. Updated April 18, 1998. Accessed March 3, 2015.
ACL Injury: Does It Require Surgery? American Academy of Orthopaedic Surgeons website. Available at: http://orthoinfo.aaos.org/topic.cfm?topic=A00297. Updated September 2009. Accessed March 3, 2015.
Griffin LY, Agel J, et al. Noncontact anterior cruciate ligament injuries: risk factors and prevention strategies. J Am Acad Orthop Surg. 2000;8:141-150.
Knee sprains and meniscal injuries. Merck Manual for Health Care Professionals. Available at: http://www.merckmanuals.com/professional/injuries_poisoning/fractures_dislocations_and_sprains/knee_sprains_and_meniscal_injuries.html. Updated December 2014. Accessed March 3, 2015.
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 March 3, 2015.
7/6/2009 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed: 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.
5/12/2014 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed: Anterior cruciate ligament injuries: Diagnosis, treatment, and prevention. Pediatrics. 2014 Apr [Epub ahead of print].
Last reviewed March 2015 by Teresa Briedwell, PT, DPT Last Updated: 5/12/2014