Knee joint replacement is surgery to replace a damaged or diseased knee joint with an artificial joint, or prosthesis. The goal is to improve the mobility and function of the knee joint and reduce pain.

Who is a candidate for the procedure?

Knee joint replacement may be used for long-standing knee pain or arthritis that has not responded to treatment with medication. It may also be used when arthritis causes the knee to function poorly, or for some knee fractures. The procedure is used for people who have a great deal of knee pain. This pain is so severe that the person cannot work, has trouble sleeping, and cannot walk more than 3 blocks. Most people who have a knee joint replacement are over the age of 55, but it can be done for anyone.

How is the procedure performed?

Knee joint replacement is performed under general anesthesia or regional anesthesia. General anesthesia means the person is put to sleep with medications. Regional anesthesia means the person will be awake, but numb below the waist. A drug may be given to make the person drowsy. The ends of the thighbone, or femur, and the shinbone, or tibia, are removed. The underside of the kneecap, or patella, may also be removed. The new knee consists of a metal shell on the end of the femur and a metal and plastic piece on the tibia. If needed, there is also a plastic button in the kneecap. The surgery itself takes about 2 hours. In many cases people donate 2 units of their own blood in the weeks before surgery to be used during or shortly after the operation.