MCL imbrication or reefing is a surgical procedure that is often used to manage instability or injury of the medial collateral ligament of the knee. The MCL is a broad ligament on the medial aspect of the knee joint that assists in the stability of the joint during movement.

In MCL imbrication or reefing procedure, the surgeon strengthens the MCL by folding or overlapping a part of the ligament and thus making it shorter and stiffer. This technique is used to provide stability to the knee joint and facilitate healing in instances where the MCL is sprained, torn, or otherwise damaged.

MCL imbrication or reefing can be done by open surgery or arthroscopy depending on the individual patient and the severity of the MCL tear. Rehabilitation after the surgery usually involves a period of inactivity, and then gradually increasing the use of the knee joint and muscles to restore muscle strength, flexibility, and Motion.