WHAT ARE THE PARTS OF THE KNEE?

Your knee is one of the largest and most complex joints in the body.

The knee is a joint between femur (thigh bone) and tibia-fibula (shin bones) with patella (kneecap) in front. It is held in place by ligaments and tendons (soft-tissues) from the front, back and sides. A lining layer called cartilage covers the articulating parts of femur, tibia and the patella. Further, while standing femur is cushioned from tibia by 2 wedges called menisci. Both knees have medial meniscus on the inner side and lateral meniscus on the outer side as cushions, and ligaments in the center and sides to hold the knee in place.

Ligaments:

Four major bundles of collagen fibers stabilize and guide knee joint motion.

• Anterior Cruciate Ligament (ACL) and Posterior Cruciate Ligament (PCL) are inside the knee. The name ‘cruciate’ means ‘cross’ and comes from the fact that these two ligaments cross each other as they attach to femur and tibia.

• Medial Collateral Ligament (MCL) and Lateral Collateral Ligament (LCL) are on either side of the knee. MCL is on the inner side attached to femur and tibia, and LCL is on the outer side attached to femur and fibula.

Muscles and Tendons:

Two sets of muscles cross the knee joint to make it move.

• Quadriceps (referred to as ‘quads’) are four muscles in front of the thigh that straighten the knee.

• Hamstrings (referred to as ‘hams’) are muscles at the back of the thigh that work together to bend the knee.

Tendons are connective structures that attach muscle to bones. Four quadriceps come together to form one tendon, which surrounds patella (kneecap) and attaches the quadriceps to tibia (shin bone). This is called the Patellar tendon.

Cartilage:

The ends of each bone (femur, tibia and patella) are covered with articular cartilage. This ‘wallpaper’ helps bones glide smoothly across each other as you bend/straighten the leg.

Menisci:

There are two C-shaped wedges called menisci (plural). Medial meniscus and lateral meniscus are cushions between femur and tibia. These rubber-like “shock absorbers” improve the fit of the two bones. When people talk about torn cartilage in the knee, they are usually referring to torn meniscus. This pamphlet is intended to provide you with information. It is not a substitute for advice from your surgeon and does not contain all known facts about the knee. You are encouraged to fully discuss your problem and treatment plan with Dr. Miten Sheth.