Anterior Cruciate Ligament Reconstruction

ACL Injury

An ACL injury is a tear or sprain of the Anterior Cruciate (KROO-she-ate) Ligament (ACL) - one of the major ligaments in your knee. ACL injuries most commonly occur during sports that involve sudden stops or changes in direction, jumping and landing - such as soccer, basketball, football and downhill skiing.

Many people hear or feel a "pop" in the knee when an ACL injury occurs. Your knee may swell, feel unstable and become too painful to bear weight.

Depending on the severity of your ACL injury, treatment may include rest and rehabilitation exercises to help you regain strength and stability or surgery to replace the torn ligament followed by rehabilitation. A proper training program may help reduce the risk of an ACL injury.

Symptoms

Signs and symptoms of an ACL injury usually include:

A loud "pop" or a "popping" sensation in the knee
Severe pain and inability to continue activity
Rapid swelling
Loss of range of motion
A feeling of instability or "giving way" with weight bearing

When to see a Doctor

Seek immediate care if any injury to your knee causes signs or symptoms of an ACL injury. The knee joint is a complex structure of bones, ligaments, tendons and other tissues that work together. It's important to get a prompt and accurate diagnosis to determine the severity of the injury and get proper treatment.

Causes

Ligaments are strong bands of tissue that connect one bone to another. The ACL, one of two ligaments that cross in the middle of the knee, connects your thighbone (femur) to your shinbone (tibia) and helps stabilize your knee joint.

ACL injuries often happen during sports and fitness activities that can put stress on the knee:

Suddenly slowing down and changing direction (cutting)
Pivoting with your foot firmly planted
Landing awkwardly from a jump
Loss of range of motion
Stopping suddenly
Receiving a direct blow to the knee or collision, such as a football tackle
When the ligament is damaged, there is usually a partial or complete tear of the tissue. A mild injury may stretch the ligament but leave it intact.

Risk Factors

There are a number of factors that increase your risk of an ACL injury, including:

Being female - possibly due to differences in anatomy, muscle strength and hormonal influences
Participating in certain sports, such as soccer, football, basketball, gymnastics and downhill skiing
Poor conditioning
Wearing footwear that doesn't fit properly
Using poorly maintained sports equipment, such as ski bindings that aren't adjusted properly
Playing on artificial turf surfaces

Treatment

First Aid

If your injury is minor, you may only need to put ice on your knee, elevate your leg, and stay off your feet for a while. You can reduce swelling by wrapping an ace bandage around your knee. Crutches can help to keep weight off your knee.

Medications

Anti-inflammatory drugs can help to reduce swelling and pain. Your doctor may suggest over-the-counter medications or prescribe something stronger.

Physical Therapy

You may need this a few days a week to get your knee back in working order. During your sessions, you'll do exercises to strengthen the muscles around your knee and help you regain a full range of motion. You may be sent home with exercise to do on your own.

Surgery

Your doctor may tell you that you need this if your ACL is torn badly, if your knee gives way when you're walking, or if you're an athlete. A surgeon will remove the damaged ACL and replace it with tissue to help a new ligament grow in its place. With physical therapy, people who have surgery can often play sports again within 12 months.

Complications

People who experience an ACL injury are at higher risk of developing osteoarthritis in the knee. Arthritis may occur even if you have surgery to reconstruct the ligament.

Multiple factors likely influence the risk of arthritis, such as the severity of the original injury, the presence of related injuries in the knee joint or the level of activity after treatment.

Prevention

Proper training and exercise can help reduce the risk of ACL injury. A sports medicine physician, physical therapist, athletic trainer or other specialist in sports medicine can provide assessment, instruction and feedback that can help you reduce risks.

Programs to reduce ACL injury include:

Exercises that strengthen leg muscles, particularly hamstring exercises, to ensure an overall balance in leg muscle strength
Exercises to strengthen the core, including the hips, pelvis and lower abdomen
Training and exercise emphasizing proper technique and knee position when jumping and landing from jumps
Training to improve technique when performing pivoting and cutting movements
Training to strengthen muscles of the legs, hips and core - as well as training to improve jumping and landing techniques - may help to reduce the higher ACL injury risk associated with women athletes.