Lateral collateral ligament

A critical structure in the knee, providing stability and support during movement.

The lateral collateral ligament (LCL) is a strong, cord-like band of connective tissue located on the outer side of the knee. It connects the femur (thigh bone) to the fibula (the smaller bone of the lower leg) and plays a key role in stabilizing the joint during side-to-side movements.

Terminologia Anatomica

ligamentum collaterale laterale

System

Musculoskeletal system

Function

The lateral collateral ligament's primary function is to maintain the stability of the knee, particularly in preventing excessive sideways motion. When the knee is subjected to lateral forces, such as during activities like running or changing directions, the LCL keeps the femur and fibula properly aligned. This stabilization is crucial for preventing injuries, particularly sprains or tears, which can occur if the knee is forced to move beyond its normal range. Proper function of the LCL allows athletes and individuals engaging in physical activities to perform optimally without the risk of joint instability. Additionally, the LCL facilitates smooth movement of the knee joint by ensuring the proper mechanics of the surrounding muscles and ligaments.

Location

The lateral collateral ligament is situated on the outer side of the knee joint, extending from the lateral epicondyle of the femur to the head of the fibula. It runs parallel to the outer thigh and lower leg, providing an external support system to the knee. Covering the LCL, the iliotibial band, a thick band of connective tissue, also contributes to the overall stability and function of the knee. Its location makes it susceptible to injury during activities that involve abrupt changes in direction or physical contact.

Did You Know?

The LCL is one of four major ligaments in the knee, along with the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), and medial collateral ligament (MCL).
Injuries to the LCL are less common than injuries to the MCL, often resulting from direct impact to the inner side of the knee.
The LCL is considered a non-weight-bearing ligament, which means it does not directly support body weight but rather stabilizes the joint during motion.