Alternative Names LCL injury, lateral knee ligament injury
Definition A lateral collateral ligament (LCL) injury involves the outside of the knee. It 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.
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. The LCL is a cord about two inches long and about the diameter of a pencil. It runs from the thigh bone to the head of the fibula, the smaller bone on the outside of the lower leg.
What are the signs and symptoms of the injury? Symptoms of a LCL injury include:
pain and swelling on the outside of the knee
weakness of the knee
discomfort on the outside of the knee when tension is applied to the strained ligament
tenderness when the area over the affected ligament is touched.
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. A blow to the outside of the knee is more likely to produce a bruise than damage to the LCL.
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.
How is the injury recognised? A doctor will often diagnose the problem based on a physical examination 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 look for other injuries.
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. Medication, such as non-steroidal anti-inflammatory drugs (NSAIDs), can be used for pain. Crutches can be helpful until the knee pain has subsided, and motion and strength in the joint have improved. Occasionally, a brace is used for a few days to immobilise the knee.
The person also needs to do knee exercises to regain flexibility in the joint and strength in the thigh muscle. physiotherapy is sometimes needed to help with this. The individual should also take care to avoid re-injuring 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 immobilised for too long. Medications have side effects, including allergic reactions and stomach upset. Other side effects depend on the medication used. Surgery carries a risk of bleeding, infection and reaction to the anaesthesia.
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 Physiotherapy go well, a person can often return to normal activities. A person may suffer some mild to moderate long-term knee problems, such as looseness or weakness of the joint, following 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 see make sure that the joint is pain free, and that strength and mobility have returned.
Author: John A.K. Davies, MD Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
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