1. Least Effective Exercises Slideshow
2. Dehydration Slideshow
3. First Aid Care and Pain Relief for Minor Injuries

Medical Author:

Benjamin Wedro, MD, FACEP, FAAEM

Benjamin Wedro, MD, FACEP, FAAEM

Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.

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Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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In this Article

• What is the function of the knee joint?
• What is a torn anterior cruciate ligament (ACL)?
• What causes a torn ACL?
• What are symptoms and signs of a torn ACL?
• How is a torn ACL diagnosed?
• What is the treatment for a torn ACL?
• How long does it take to recover from a torn ACL?
• Can ACL tears be prevented?
• Torn Anterior Cruciate Ligament (ACL) At A Glance
• Patient Comments: Torn ACL - Causes
• Find a local Doctor in your town
• Torn ACL Index

Rehabilitation and return to normal function after surgical repair of an ACL tear can take nine months or more. There needs to be a balance between trying to do too much work in physical therapy returning strength and range of motion and doing too little. Being too aggressive can damage the surgical repair and cause the ligament to fail again. Too little work lengthens the time to return to normal activities.

More than 80% of people who have surgery to repair their ACL have good return of function and lifestyle. Less than 10% of patients develop permanent knee instability.

For patients who do not have surgery to repair a torn ACL, 50% have a fair outcome with no knee instability.

ACL injuries usually occur in active people engaged in activities that are enjoyable. The risk of injury can be decreased in three ways.

1. Increase the strength of the muscles of the thigh, especially the hamstrings, and maintaining a balance between the quadriceps and hamstring muscles.



2. Increase flexibility.



3. Increase proprioception or the ability to know where the body is in space. Increased agility and balance decreases injury potential. This includes always trying to avoid landing on a fully extended and locked leg.

• The anterior cruciate ligament is one of the four ligaments in the knee that provides stabilization.
• ACL tear or sprain occurs when a sudden change in direction or pivot occurs on a locked knee.
• Initial symptoms of ACL tears include a loud pop that is heard, pain, and swelling.
• Arthroscopic surgery is often required to repair the damage to allow return to pre-injury activity. Some patient may choose a nonoperative approach or may not be candidates for surgery.
• It may take more than nine months to return to normal activity after an ACL injury.

REFERENCE:

Buchholz, R.W., et al. Rockwood and Green's Fractures in Adults. 6th edition. Philadelphia: Lippincott, Williams and Wilkins, 2006.