The knee joint is comprised of four bones, the femur (thigh bone), the Patella (knee cap), the Tibia (shin bone) and the Fibula all of which are held together by tendons and ligaments. On the outside or lateral side the knee is the Lateral Collateral Ligament (LCL), on the inside or medial side of the knee is the Medial Collateral Ligament (MCL). In the center of the knee joint, the Anterior Cruciate Ligament (ACL) and Posterior Cruciat Ligament cross (cruciate) and hold the femur and tibia together.

In the knee, there is cartilage on the underside of the kneecap (patella) and where the kneecap rides on the femur (trochlea), on the ends of the femur (medial and lateral femoral condyle), and on the tibia (tibial plateau). This cartilage is different than the other cartilage in the knee, the meniscus, which are the cartilage rings inside the knee joint.

The meniscus are cartilage rings found on both the inside and outside of the knee. They sit between the femur (thigh bone) and tibia (shin bone), and act as shock absorbers in the knee. In addition, they provide some stability to the joint.

• Patient Guide to Articular Cartilage Injury (1.1Mb)

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