The knee joint is a hinge joint that connects the thigh bone (femur) to the shin bone (tibia) in the lower leg. It is the largest joint in the body and allows for movement, such as walking, running, and bending.
The knee joint is made up of several components, including:
- Articular cartilage: This is the smooth, white tissue that covers the ends of the bones in the knee joint. It helps to reduce friction and allows for smooth movement of the joint.
- Synovial fluid: This is the clear, viscous fluid that is produced by the synovial membrane and helps to lubricate the joint.
- Synovial membrane: This is the thin, transparent membrane that lines the joint capsule and produces synovial fluid.
- Ligaments: There are four ligaments in the knee joint that help to stabilize the joint and prevent excessive movement. The ligaments include the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL), and lateral collateral ligament (LCL).
- Tendons: The tendons in the knee joint connect the muscles to the bone and help to move the joint.
- Menisci: The menisci are two crescent-shaped pieces of cartilage that sit between the femur and tibia and help to distribute weight and absorb shock in the knee joint.
- Bursae: The bursae are small, fluid-filled sacs that help to reduce friction and cushion the joint.