Anatomy of Knee

The major bones of the knee

The knee joint is comprised of four bones; femur (thigh), tibia (shin), fibula (shin): patella (kneecap) not shown.
The surfaces that come in contact with other bones are coved with a slippery smooth surface (cartilage).

View of the front of the knee with leg flexed. The kneecap has been removed to show interior structures.

Four major ligaments stabilize the knee joint.
The collateral ligaments (lateral collateral (LCL), medial collateral (MCL))

The cruciate ligaments (anterior cruciate (ACL), posterior cruciate (PCL))

Side view of knee illustrating the anatomy and posiitoning of the ACL and PCL.

The ACL and PCL limit the anterior (forward) and posterior (backwards) motion of the knee.

Specifically, the ACL limits forward motion of the tibia, while the PCL limits backward motion. Both ligaments also limit rotation of the tibia.

Proximal (top) surface of tibia that contacts distal (bottom) surface of femur

The C Shaped menisci help distribute the forces that are transmitted between the femur and tibia. This helps to protect the cartilage that covers the ends of the femur and tibia.

Any of these structures can be injured (bones, ligaments, meniscus, cartilage). Fortunately, recent surgical advances allow us to repair or reconstruct much of the damage that may occur following an injury.