What are the Collateral Ligaments?

If you have not yet reviewed the general knee anatomy page, please do so now. The MCL (Medial Collateral Ligament) and the LCL (Lateral Collateral Ligament) are two of the four stabalizing ligaments of the knee. They keep the tibia from moving too far from side to side in relation to the femur.

How are the collateral ligaments injured?

The collateral ligaments are commonly injured structures in the knee. These injuries usually occur when a significant force is put on the side of the leg, such as a fall while skiing. The most common combination ligament tear is a tear of the medial collateral ligament and the anterior cruciate ligament. The medial collateral ligament is injured more often than the lateral collateral ligament. This is because the MCL is stressed more when the foot is planted and the knee is struck from the outside. LCL tears do occur, but they occur more infrequently than MCL tears.

What are the symptoms of a collateral ligament injury

A tear of one of the collateral ligaments will result in swelling near the outside of the knee, on whichever side the ligament was torn. Swelling can also occur inside of the knee joint as a result of blood from the torn ligament entering the knee joint. The knee is stiff and painful and may feel unstable and unable to hold your body weight.

How is a collateral ligament injury diagnosed?

Swelling within a couple of hours of a knee injury is usually a good indicator of a torn ligament. A collateral ligament tear is best diagnosed by a physical examination by an orthopedist. If the orthopedist suspects a tear or injury to the ligament, he will usually confirm that diagnosis with an MRI scan. He may also take some X-rays to be sure that no bones are injured.

How is a collateral ligament injury treated??

Most injuries to the collateral ligaments will heal on their own in about 4-6 weeks with the aid of a cast or a brace. Injuries to these ligaments rarely require surgical repair or reconstruction. The biggest help in treating a collateral ligament injury is to decrease swelling of the knee. The best way to do this is to take an anti-inflammatory medication (such as ibuprofen) and to rest, ice and elevate the afflicted leg and maintain range of motion. In the case of an injury to both the MCL and the ACL, surgery will be required to reconstruct the ACL and possibly the MCL also, depending on what your orthopedist feels is necessary.