Anterior cruciate ligament

A key ligament in the knee joint, crucial for stabilizing movement and preventing excessive motion.

The anterior cruciate ligament (ACL) is one of the four primary ligaments in the knee that connect the thigh bone (femur) to the shin bone (tibia). It is located within the knee joint, running diagonally across the front of the joint, and is vital for maintaining knee stability during activities that involve pivoting, jumping, or sudden changes in direction.

Terminologia Anatomica

ligamentum cruciatum anterius

System

Musculoskeletal system

Function

The main function of the anterior cruciate ligament is to provide stability to the knee joint during dynamic activities. It helps limit the forward movement of the tibia in relation to the femur and also plays a crucial role in preventing excessive rotation and hyperextension of the knee. When engaging in sports or activities that require quick lateral movements or rapid deceleration, the ACL absorbs and distributes forces, reducing the risk of knee injuries. A healthy and intact ACL is essential not only for athletic performance but also for everyday movements, as it helps control the degree of motion and stability required during various activities.

Location

The anterior cruciate ligament is located in the center of the knee joint. It originates from the medial aspect of the lateral femoral condyle (the rounded end of the thigh bone) and extends diagonally downwards to attach to the anterior part of the tibia. This ligament crosses over the posterior cruciate ligament (PCL) and is positioned between the femur and tibia, making it a central component of the knee's intricate ligamentous structure. Its depth within the knee joint places it at risk for injuries, particularly during sports that involve sudden changes in movement patterns.

Did You Know?

The ACL is one of the most commonly injured ligaments in the knee, especially among athletes participating in sports like soccer and basketball.
Injuries to the ACL can lead to a feeling of instability in the knee, often causing individuals to feel as though their knee might 'give way'.
ACL injuries often require surgical intervention followed by extensive rehabilitation to restore knee function.
The ACL is often examined using a pivot shift test, which assesses the ligament's integrity during movement.