The anterior cruciate ligament is one of the primary stabilizing ligaments of the knee articulation. The ligament travels from posterior to anterior (back to front) and top to bottom connecting the femur and the tibia.
There are other ligaments that support the joint, but consider the primary direction of joint movement. The knee has the greatest movement in the forward/backward direction. Side to side movement is minimal in part, because of the cup-like shape of the menisci (cushion pads) between the tibia and femur bones.
If the anterior cruciate ligament is damaged/torn/elongated, there is little (other than muscular tension) to prevent excessive movement of the joint. Excessive movement of joints results in instability of the joint. Ramifications include:
- short term - pain, inflammation, additional ligamental damage
- long term - potential dislocation, degenerative arthritic changes
These degenerative changes typically lead to calcified ligaments and thinning of the "pads" producing bone-to-bone contact. If severe, these are common precursors to knee replacement operations.