The dreaded ACL rupture epidemic: Part 2 "Anatomy of an ACL rupture"

Functional Anatomy of the Knee

The knee joint consists of three bones, muscles and many ligaments. The shin bone (tibia), the thigh bone (femur) and the knee cap (patella) form the knee. The primary muscles are the quadriceps on the top of the thigh and the hamstrings on the back of the thigh. These muscles are primary controllers of how the knee moves.

 

Ligaments attach the bones together to allow the muscles to move the knee in a controlled and predictable fashion.  The knee has four main ligaments that control stability when you walk, run, and pivot. Two ligaments protect the stability of the knee from the side and are called collateral ligaments and two ligaments attach the thigh bone and shin bone from the center of the knee. The anterior cruciate ligament (ACL) is one of a pair of ligaments that cross at the center of the knee joint. This ligament crosses with the posterior cruciate ligament (PCL). This pair of ligaments work together to stabilize the knee from front to back during normal and athletic movements. They function to keep the knee joint centered and prevent wear and tear on the joint cartilage inside the knee.

The knee has shock absorbing pads between the thigh and shin bone to protect from wear and tear. These structures are called the medial and lateral meniscus. Each pad is horseshoe shaped and absorbs weight when the foot contacts the ground and allows for frictionless movement at the knee joint.

Next week the post will be discussing Part 3 of this series: ACL rupture injury mechanisms