Knee Anatomy

The knee is the largest joint in the body. It is made up of components that
normally work in harmony. But disease or injury can disrupt this harmony,
resulting in pain, muscle weakness and increased friction.

The knee is made up of three main parts:

Femur - lower end of the thigh bone
Tibia - upper end of the shin bone
Patella - knee cap, which slides in a groove on the end of the femur

The joint surfaces where these three bones touch are covered with articular cartilage, a smooth substance that cushions the bones and enables them to move
easily.

All remaining surfaces of the knee are covered by a thin, smooth tissue liner that releases a special fluid to lubricate the knee. This eliminates friction almost completely in a healthy knee.