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
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.