Anatomy of the Knee

Bones

Your knee joint consist of three bones:
• Femur (thighbone)
• Tibia (shinbone)
• Patella (kneecap)
The kneecap is positioned in front of the knee joint to provide some protection.

Ligaments

Collateral ligaments are on the side of the knee — the medial ligament (MCL) is on the inside of your knee; the lateral ligament (LCL) is on the outside. These ligaments control the sideways motion of the knee.

Cruciate ligaments run diagonally inside the middle of the knee, forming an “X”, with the anterior cruciate ligament (ACL) in the front part of the knee, and the posterior cruciate ligament (PCL) in the back. These ligaments control the back and forth motion of the knee.

Cartilage: Knee

There are two common types of cartilage in the knee.

The first type is the meniscus. The meniscus is the semicircular soft cartilage cushion in the knee. There is one on the inner side (medial meniscus) and one on the outer side of the knee (lateral meniscus) between the thigh bone (femur) and the shin bone (tibia). These menisci help the knee to function properly by bearing load and, absorbing shock and stress, stabilising the joint and providing lubrication.

The second type is articular cartilage which forms a lining and coats the joint surfaces to absorb stress and allow smooth joint movement with minimal friction.