Treatment Overview

There are three main treatment goals. The first goal is to stabilize the knee if it is unstable—or at least stabilize it enough to suit your lifestyle. The second goal is to return your knee to normal or almost normal functioning. The third goal is to reduce the likelihood of further damage to the knee. Treating anterior cruciate ligament (ACL) injuries may also help to reduce pain, prevent osteoarthritis, and prevent loss of strength and decreased movement in the knee.

Initial treatment of an acute ACL injury consists of using first aid steps to stabilize your knee and reduce swelling and pain.

Later treatment may include several months of rehabilitation or surgery with rehabilitation. Not all ACL tears require surgery. Further treatment is nearly always a decision you and your doctor make between rehabilitation only and surgery plus rehabilitation.

Acute (sudden) ACL injuries

If you know you have injured your ACL, initial treatment consists of:

• First aid steps to reduce swelling and pain. This may include resting the knee, applying ice, using gentle compression with an elastic bandage, elevating the leg, and taking pain medicines, such as acetaminophen or nonsteroidal anti-inflammatory drugs (NSAIDs).
• Using crutches and/or immobilizing splints in the first few days after an injury. If crutches or splints are used for too long, the muscles will become weaker from too little activity, and movement of the knee will become stiff and restricted.
• Strength and motion exercises to help prepare you for treatment. For more information, see:

  ACL injury: Exercises to do before treatment.

For information on specific first aid steps to take immediately after the injury, see the Home Treatment section of this topic.

Further treatment

After initial treatment for an anterior cruciate ligament (ACL) injury, further treatment of the injury depends on:

• How much of your ACL is torn (whether it is a grade I, II, or III sprain).
• When the injury occurred and how stable your knee is.
• Whether other parts of the knee are injured. If other parts of your knee are injured, it will be harder for the strong parts of your knee to compensate and protect the injured parts.
• Preexisting conditions of the knee, such as prior injuries that resulted in long-term (chronic) ACL deficiency, or osteoarthritis.
• How active you are.
• Your age and overall health status.
• Your willingness and ability to complete a long and rigorous rehabilitation.

Treatment options include:

• Nonsurgical treatment only, such as a physical rehabilitation program.
• ACL surgery to reconstruct the ACL or to reconstruct the ACL and repair injuries that occurred at the same time, such as a meniscus tear. Most ACL surgery is done by making small incisions in the knee and inserting instruments for surgery through these incisions (arthroscopic surgery). Open surgery (cutting a larger incision in the knee) is sometimes required. Physical rehabilitation always follows surgery.

For more information, see:

Should I have surgery for an ACL injury?

Recovery from an ACL injury varies with each individual. Your treatment should continue until your knee is stable and strong, not for a certain length of time.

Treatment in children and teens

Anterior cruciate ligament (ACL) injuries in children and teens are less common than in adults, but they do occur, especially in teens. An untreated or unsuccessfully treated ACL injury in children or teens may result in future knee problems. The knee may become more and more unstable and, over time, osteoarthritis may develop.

A child with an ACL injury can sometimes be treated without surgery in order to avoid damage to the child's still-developing bones. Nonsurgical treatment includes rehabilitation exercises, wearing a brace, and avoiding activities that require jumping or twisting. Nonsurgical treatment is not always successful. A child's level of activity is a strong factor in how successful treatment is. Studies suggest that the more active a child is, the less likely nonsurgical treatment will be successful and the more likely surgery will be needed in the future.⁴

An avulsion fracture (a separation of the ligament and a piece of the bone from the rest of the bone) is more common in young children. It can often be treated with a cast but sometimes needs surgery.

Surgery in a child might be necessary to prevent injury to other structures within the knee, such as the menisci. You may consider surgery if the child's knee is very unstable doing simple daily activities, if the knee's instability cannot be controlled with nonsurgical methods, if the child has both an ACL injury and a meniscus tear, or if the child is a serious athlete in sports that require running, jumping, and decelerating. Postsurgery rest and a sustained rehabilitation program are extremely important.⁵

The main risks of surgery in a child whose bones are still growing is slowed growth (physeal arrest), which may result in one leg being longer than another. Other risks include the thigh bone pointing inward (distal femoral valgus or angular limb deformity). The closer a child or teen is to skeletal maturity, the lower the risk of these conditions.

What To Think About

Things that you should consider about treatment options include:

• Your goals for recovery. How stable and strong do you want your knee to be? What activities do you hope to return to?
• How motivated you are to complete a long and rigorous rehabilitation program. Are you able to complete a rehabilitation program?

Depending on how severe your injury is, surgery with rehabilitation may offer the best chance of making your knee stable again and of continuing an active lifestyle without further pain, injury, or loss of strength and movement in your knee. Age is not a factor, although your overall health may be. Surgery may be done for adults at any age who want to continue activities that require a strong, stable knee.

If your initial injury resulted in an unstable knee that occasionally gives out (chronic ACL deficiency) and you continue to participate in activities that require a stable knee and don't have surgery, you may injure your knee again.

You will need to follow a rehabilitation program whether or not you have surgery. If you do not complete a rehabilitation program, even with surgery you may not regain full stability and function in your knee.

You may choose to start a rehabilitation program to avoid or delay knee surgery by strengthening and developing flexibility in the muscles that support the knee (hamstrings and quadriceps). If you eventually need surgery, you will be much better conditioned for it and for the rehabilitation that follows.

An avulsion fracture (a separation of the ligament and a piece of the bone from the rest of the bone) is rare in adults. But when this fracture occurs in adults, surgery may be needed to reattach the bones.