Collateral and Cruciate Ligament Injuries

The knee is the largest and one of the most complex joints in the human body. It consists of 4 bones, multiple ligaments, muscles and tendons, cartilage and soft tissue. Knee ligaments connect bones to bones allowing for stability.

• Ligaments of the knee are classified as cruciate and collateral ligaments. Ligaments connect bone to bone. The major ligaments of the knee consist of the ACL (anterior cruciate ligament, PCL (posterior cruciate ligament), MCL (medial collateral ligament) and LCL (lateral collateral ligament).
  • Cruciate ligaments are within the knee joint. They prevent anterior (forward) and posterior (backward) translation of the femur from the tibia. The ACL is the most injured ligament in the knee complex.
  • Collateral ligaments are outside the knee joint and prevent medial (inside) and lateral (outside) instability. Ligaments here are injured with a varus stress the LCL (inside to outside force) or valgus stress the MCL (outside to inside force)

Injuries to these ligaments are called tears or sprains. Ligament sprains are classified on a severity scale called grades.

• Grade 1 sprains occur with mild