Medial collateral ligament

Medial Collateral Ligament

The medial collateral ligament of the knee. Image courtesy of Wikimedia Commons.

The Medial Collateral Ligament (MCL) is one of the four major ligaments of the knee. It is located on the inner part of the knee joint and connects the femur (thigh bone) to the tibia (shin bone). The MCL's primary function is to resist widening of the inside of the joint, or prevent "opening-up" of the knee.

Anatomy

The MCL extends from the medial epicondyle of the femur to the medial condyle of the tibia. The ligament is divided into two separate components: the deep MCL and the superficial MCL. The deep MCL is a thickening of the joint capsule and is contiguous with the medial meniscus, while the superficial MCL is the primary restrictor against valgus force.

Function

The MCL's main task is to prevent the leg from extending too far inward, but it also helps to stabilize the knee and allows it to rotate.

Injury

Diagram showing the location of the MCL in the knee. Image courtesy of Wikimedia Commons.

Injuries to the MCL are often caused by a direct blow to the outside of the knee, which can stretch or tear the ligament. Symptoms of an MCL injury include pain, swelling, and instability in the knee. Treatment for MCL injuries depends on the severity of the injury, and can range from rest and physical therapy to surgery.

See Also

• Ligament
• Knee
• Femur
• Tibia