What Are the Symptoms of a Medial Collateral Ligament Tear?

Symptoms of a medial collateral ligament tear vary depending on the severity of the injury. Ligament tears are rated from grade one to three, with grade three sprains the most severe. Symptoms of a grade one tear can be as minor as mild pain on the inside of the knee with no instability in the joint. Grade three tears to the medial collateral ligament (MCL) usually involve a complete rupture of the ligament, resulting in pain and a highly unstable knee.

The MCL is situated on the inner side of the knee joint. Its function is to connect the thigh and shin bones and, in doing so, stabilize the joint. If the ligament becomes damaged, it can no longer perform this role adequately, which allows the gap between the bones to widen under stress. This is known as joint laxity and is a common problem among athletes with a medial collateral ligament tear. An MCL tear is nearly always caused by a forceful blow to the side of the knee.

Ligaments are made up of fibers which become torn during an injury. In a grade one tear, less than 10% of the ligament fibers are damaged so the injury is usually relatively quick to heal. Symptoms of a grade one medial collateral ligament tear can include a small amount of pain on the inside of the joint as well as some tenderness. There is usually little or no swelling and there should be no laxity in the joint.

A grade two medial collateral ligament tear is more serious than a grade one sprain because more ligament fibers are involved. There will often be significant pain on the inside of the knee joint and the area usually feels very tender to touch. Depending on how much of the ligament has torn, there may also be some swelling. In a grade two tear, the ligament is not torn completely, but the injury usually causes the joint to become very unstable.

If the medial collateral ligament is completely torn, it is classifed as a grade three. In some athletes, this results in severe pain, while for others the pain is surprisingly mild. All those who suffer from a complete medial collateral ligament tear have a large amount of laxity in the joint. This can also result in the knee becoming unstable to walk on. Surgery is sometimes required to address a complete MCL rupture, so it’s important for an athlete to consult a sports therapist immediately after sustaining the injury.