Knee replacement is an operation to replace the knee joint with metal and plastic components.
The lower end of the thigh bone (femur) and top end of the shin bone (tibia) are removed and the bone ends are replaced with a metal piece on the lower end of the thigh bone and a plastic or metal component on the top end of the shin bone.
The back of the kneecap (patella) may also be resurfaced. The operation is done to relieve pain which is usually caused by wear and tear of the knee joint. The operation may also increase the mobility of the knee.