Knee Replacement, also called Knee Arthroplasty or Total Knee Replacement, is a surgical procedure to replace a damaged or worn-out knee joint with an artificial joint, called a prosthesis. The knee joint is made up of the lower end of the thigh bone (femur), the upper end of the shin bone (tibia), and the kneecap (patella). This surgery may be considered for someone who has severe arthritis or a severe knee injury.