Knee Arthroplasty is also known as Knee replacement surgery. The knee is the largest joint in the body and having healthy knees is required to perform most everyday activities. Arthroplasty is a field of medicine which deals with the surgical reconstruction and total replacement of degenerated joints. Arthroplasty uses artificial body parts (prosthetics). Arthroplasty literally means "the surgical repair of a joint". The knee is made up of the lower end of the femur (thighbone), the upper end of the tibia (shinbone), and the patella (kneecap). The ends of these three bones where they touch are covered with articular cartilage, a smooth substance that protects the bones and enables them to move easily.