Overview, Causes, & Risk Factors

The lateral collateral ligament is the main supporting structure on the outside of the knee. It provides stability to the joint when the knee is pushed outward. A lateral collateral ligament (LCL) injury is usually a mild problem. There are three degrees of ligament injuries. A first-degree injury consists of only mild stretching of the ligament. There is no looseness. A second-degree LCL is a partial tear of the ligament. In a third-degree injury, the ligament is completely ruptured, and the joint is unstable.

What are the causes and risks of the injury?

A force applied to the inside of the knee causes this type of injury. This most often happens while playing sports. An LCL injury can also be caused by overuse of the joint, and by falls in an elderly individual.

Symptoms & Signs

What are the signs and symptoms of the injury?

Symptoms of an LCL injury include:

Diagnosis & Tests

How is the injury recognized?

A healthcare provider will often diagnose the problem based on a physical exam and the person's description of how the injury occurred. Joint X-rays of the knee are usually ordered. A special X-ray called an MRI is used in some cases to reveal the amount of damage and to look for other injuries.

Prevention & Expectations

What can be done to prevent the injury?

Many LCL injuries cannot be prevented. However, to lessen the risk of injury, a person should be in good physical shape before engaging in sporting activities. Sports safety guidelines should be followed for adults, adolescents and children. Proper stretching exercises should be done prior to athletic activity.

Treatment & Monitoring

What are the treatments for the injury?

The treatment for LCL injuries depends on the severity of the problem. The kind of activities a person is likely to do in the future is also taken into account. RICE, which stands for rest, ice, compression with an ace bandage, and elevation of the leg, is the standard initial treatment. Medicine, such as nonsteroidal anti-inflammatory drugs (NSAIDs), can be used for pain. Crutches can be helpful until motion and strength in the joint have improved. Occasionally, a brace is used for a few days to immobilize the knee.

The person also needs to do knee exercises to regain flexibility in the joint and strength in the thigh muscle. Physical therapy is sometimes needed to help with this. The individual should also take care to avoid reinjuring the joint before it has completely healed. Surgery may be needed in severe cases where the ligament has been torn and the knee is unstable.

What are the side effects of the treatments?

The knee can be come stiff and weak if it is immobilized for too long. Medicines may cause allergic reactions and stomach upset. Surgery carries a risk of bleeding, infection, and reaction to the anesthesia.

What happens after treatment for the injury?

After proper treatment and rehabilitation, there are usually no long-term effects from a first-degree LCL injury. If treatment and physical therapy go well, a person can often return to normal activities. A person may suffer some mild to moderate long-term knee problems after a second-degree injury. Joint instability may result from a third-degree injury.

The individual is checked to make sure he or she recovers adequate stability and function in the injured knee. The person will also be followed to make sure that the joint is pain free and that strength and mobility have returned. Any new or worsening symptoms should be reported to the healthcare provider.