Your knee is the largest joint in your body. Because it’s a complex joint with many components, the knee is vulnerable to injury. In fact, it’s the most commonly injured joint treated by orthopedic surgeons.
The bones of the leg – the femur and tibia – meet to form the knee, which is a hinge joint. The kneecap, or patella, protects the joint in front. The knee joint also is cushioned by articular cartilage, the lateral meniscus and medial meniscus – more pads of cartilage that help absorb shock between the bones.
The knee contains large ligaments that provide stability. Collateral ligaments on the sides of the knee limit side-to-side motion. The anterior cruciate ligament (ACL) connects the tibia to the femur at the center of the knee and helps limit rotation and forward motion of the tibia. The posterior cruciate ligament (PCL) is located just behind the ACL and keeps the tibia from moving backward.
In addition to knee injuries, the joint may develop pain and other problems due to arthritis, repetitive trauma or wear and tear over a period of years. When medications, therapies and other treatments are no longer effective, knee replacement surgerymay be an option. More than half a million knee replacement procedures are performed in the U.S. each year.