What is the medical name for the kneecap?

The medical name for the kneecap is the patella. It is a flat, roughly triangular sesamoid bone embedded in the tendon of the quadriceps muscle at the front of the knee. The patella connects the quadriceps tendon above with the patellar ligament below, which attaches to the tibia.

When the knee bends and straightens, the patella glides in a groove at the end of the femur called the trochlear groove. Its position helps protect the knee joint and improves the leverage of the quadriceps, making it easier to extend the lower leg. The rear surface is covered with thick articular cartilage to reduce friction during movement.

The patella is commonly injured in falls, direct blows, or sports accidents, and it can also move out of its normal track, a problem known as patellar dislocation. A frequent mix-up is naming the femur, tibia, or fibula: the femur is the thigh bone, the tibia is the larger lower-leg bone, and the fibula is the thinner lower-leg bone. The patella is the distinct bone at the front of the knee.