The medial collateral ligament (MCL) is one of the four major ligaments of the knee. The MCL is located on the inside (medial side) of the knee and connects the femur to the tibia. It helps provide stability to the knee and minimize stress across the knee joint.
The MCL is typically injured from a blow to the outside of the knee. Once the ligament tears, it heals very slowly. MCL tears can occur as isolated injuries or can be associated with other knee injuries. The combination of an ACL tear, MCL tear, and medial meniscus tear is referred to as the “unhappy triad.”
The most common symptom following an MCL injury is pain directly over the ligament on the inside of the knee. Swelling and decreased knee motion are also common with this injury. MCL injuries are graded on a scale of I to III. A grade I injury is a small tear within the ligament. A grade II injury is a medium sized tear. A grade III injury is a complete tear of the MCL and is commonly associated with tears of other ligaments in the knee.
Most MCL tears heal on their own without the need for surgery. A brace is often prescribed to protect the ligament while it heals. Grade I and grade II injuries usually resolve within 4-6 weeks, though full recovery may take longer. Grade III injuries are more severe injuries that are usually associated with tears of other ligaments in the knee and may require surgery. Surgical repair of the MCL is usually done through an open incision and involves stitching the ligament back together or down to bone. Postoperative recovery is variable and depends on what other injuries are present in the knee.