Medial collateral ligament (MCL) injury refers to a sprain, partial tear or complete tear of the ligament that traverses the inside of the knee. The MCL stretches from the thighbone (femur) to the shinbone (tibia) and helps to stabilize the inner or medial part of the knee. The MCL is the most important structure that prevents the inner part of the knee from “gapping open” when the tibia bone is pulled outward.
MCL injury is the most common knee injury, especially in athletes, such as soccer and football players as well as skiers. Most MCL injuries occur when the knee is subjected to a force that causes the tibia to bend outwards relative to the femur. The injury is categorized as first degree (sprain), second degree (partial tear) or third degree (complete tear).
“MCL sprains and tears are identified by a ripping or popping sensation on the inner line of the knee,” says Andrew Pearle, M.D., orthopaedic surgeon at Hospital for Special Surgery in New York. “Symptoms include knee instability, swelling and pain along the inside of the joint.”
The severity of a sprain or tear is diagnosed through a physical examination, MRI or X-ray to assess the injury as well as damage to the bone. The majority can be treated without surgery.
Immediately following the injury, the MCL should be iced and the joint elevated above the heart to control swelling. The patient should take non-steroidal anti-inflammatory drugs (NSAIDs) and refrain from physical activity until the swelling stops. Surgery should be considered for an MCL that does not heal or restore stability to the inner knee after a considerable period of rest. Surgical options include repair or reconstruction of the ligament. If the ligament is reconstructed, either the patient’s own tissue cadaveric tissue is used.
“The prognosis for mild MCL sprains is usually good as long as the patient avoids activity and wears a knee brace or splint,” according to Dr. Pearle. “Knee and leg exercises to build strength are also important. If the patient undergoes surgery, at least six months of rehabilitation is needed before returning to play.”