ACL & Other Ligament Tears

Ligaments are tough connective tissue that are elastic. In the knee joint, there are four ligaments that provide structure and support to the knee. These ligaments also constrain the movement of the knee, providing stability to the joint.

The four different ligaments in the knee connect the femur (thighbone) to the tibia (shinbone):

• Anterior cruciate ligament (ACL): Controls or limits forward and rotational movement of the tibia. The ACL is located in the center of the knee. This is the most common ligament to tear.
• Posterior cruciate ligament (PCL): Controls or limits backwards movement of the tibia. The PCL is also located in the center of the knee.
• Medial collateral ligament (MCL): Provides stability to the inner knee.
• Lateral collateral ligament (LCL): Provides stability to the outer knee.

Ligament damage includes stretching of the ligament, partial tear, or complete tear. A stretch or tear to a ligament often occurs from a sudden twisting motion of the knee or from direct impact to the knee. Symptoms of ligament injury include pain, swelling, and a feeling of knee instability. You may also hear or feel a pop or snap at the time of injury.

Knee Pain