MCL Tear

Signs and Symptoms

The medial collateral ligament (MCL) is a broad, thick band that runs down the inner part of the knee, from the femur (thighbone) to about four to six inches from the top of the tibia (shinbone).The MCL's primary function is to prevent the leg from over-extending inward, but it also is part of the mechanism that stabilizes the knee and allows it to rotate.

Injuries to the MCL commonly occur as a result of a strong force hitting the outside of the knee that causes the MCL -- and, possibly, other ligaments on the inside of the knee, such as the anterior cruciate ligament (ACL) -- to stretch or tear. This can happen while playing sports, for example during a clip block in football, where one player collides with another player from the side. In addition, MCL tears occur in sports where there are a lot of quick stops and turns, such as soccer, basketball and skiing. Slipping on ice, if your lower leg splays out, also can produce the same result. Another cause of injury is repeated stress, where the MCL loses its normal elasticity and becomes limp, like a worn-out rubber band.

Initial symptoms of a MCL tear include pain, stiffness, swelling and tenderness along the inside part of the knee. Depending on the severity of the injury, the pain can range from mild to acute. In addition, the knee may feel unsteady, or it may lock or "catch."

Diagnosis

Your doctor will likely ask how you injured your knee, how it has been feeling since the injury and if you've injured your knee before. He or she will check for pain or tenderness along the inside of the knee. In addition, your doctor will approximate the cause of the injury by exerting pressure on the outside of your knee while your leg is both bent and straight.

Depending on the degree of pain or looseness of your knee joint, the injury will be classified as one of three grades:

• Grade 1 -- There is some tenderness and minor pain at the point of the injury.

• Grade 2 -- There is noticeable looseness in the knee ("opening up" approximately five millimeters) when manipulated by hand, major pain and tenderness at the inside of the knee, and in some cases swelling.

• Grade 3 -- There is considerable pain and tenderness at the inside of the knee along with some swelling and marked joint instability (the knee opens up approximately one centimeter when manipulated). A grade three MCL tear often occurs in conjunction with an ACL tear or, more rarely, with a PCL tear.

In some cases, the immediate pain and swelling may make it too difficult for your doctor to accurately gauge the severity of the injury. If this occurs, you may be asked to wear a light splint and ice and elevate your knee until the swelling and pain lessen, so that an accurate diagnosis can be made.

In addition, your doctor may order the following tests:

• X-ray -- To assess for other damage and bone injury

• Magnetic Resonance Imaging (MRI) -- This test is 90 percent accurate in diagnosing MCL injuries and may be ordered if the physical examination is unclear or if your doctor suspects that you have other injuries.

• Stress X-ray -- This also may be used to look for ligament tears. Although this test is similar to a normal X-ray, the doctor or technician will hold the knee open from the side so that any widening of the joint space will be evident on the X-ray.

Treatment

On average, it takes six weeks for a MCL injury to heal. The initial treatment for most grade 1, 2 or 3 MCL tears focuses on reducing the pain and inflammation in the knee while immobilizing the knee to keep it stabilized. This includes:

• Resting, icing and elevating the knee
• Taking pain relievers, such as aspirin and ibuprofen, to ease pain and swelling
• Wearing a lightweight cast or brace that allows your knee to move backward and forward while restricting side-to-side movement. It usually is recommended to keep the knee immobilized like this for 72 hours, depending on the severity of the injury.

The cast or brace may be designed so that you cannot bend your knee at all. If this is the case, you will need to modify your behavior so that you can avoid having to squat, kneel down or bend over. You should try to keep your leg elevated even if you are sitting in a chair, to reduce blood flow to the knee.

Once the pain and swelling subside, you will begin rehabilitation, which will include exercises to restore strength and normal range of motion to your knee. If your knee feels sore while you are doing these exercises, you should proceed slowly to prevent further irritation.

If the torn ligament does not heal sufficiently, you may experience instability in the joint, and you will be more susceptible to re-injury. The MCL usually responds very well to non-surgical treatment, although surgery may be required in rare cases. Depending on the severity of the injury, a period of rest, bracing and physical therapy usually is sufficient to heal the tear.

Once the MCL has healed fully, you should have a minimum of long-term effects, providing there was no other damage to the knee.

Recovery times differ depending on the severity of the injury:

• A minor, or grade 1, MCL tear can take from a few days to a week and a half to heal sufficiently for you to return to normal activities, including sports.

• A grade 2 tear can take from two to four weeks to heal.

• A grade 3 tear usually takes from four to eight weeks to heal, unless it is associated with damage to the ACL, in which case the recovery time may be longer.