Total Knee replacement or total knee arthroplasty is just "a lining" of the knee joint. The thigh bone or femur is covered or replaced by an anatomically molded metal structure and the plastic component is placed on the tibia so that instead of irregular arthritic surfaces, one has the metal and plastic articular that produces a smooth surface. In most cases, the articular surface of the kneecap or patella is also replaced by a plastic surface so it articulates with the femoral surface. The current knee replacement procedure involves the use of general anesthesia with a hospital stay of two to four days. The surgery takes between 1 ½ and 2 ½ hours. Weight support begins immediately on the first day after the surgery. Patients usually use a walker or crutches for a period of one to two weeks. People are able to walk after three weeks and have almost total recovery for basic life activities after three months.