Knee replacement surgery — also known as knee arthroplasty (ARTH-row-plas-tee) — can help relieve pain and restore function in severely diseased knee joints. During knee replacement, a surgeon cuts away damaged bone and cartilage from your thighbone, shinbone and kneecap and replaces it with an artificial joint made of metal alloys, high-grade plastics and polymers.

The first artificial knees were little more than crude hinges. Now, you and your doctor can choose from a variety of designs that take into account your age, weight, activity level and overall health. Most knee replacement joints attempt to act like your knee, with its ability to roll and glide as it bends.

Most total knee replacement operations involve replacing the joint surfaces at the end of your thigh bone (femur) and at the top of your shin bone (tibia).

A total knee replacement may also involve replacing the under-surface of your kneecap (patella) with a smooth plastic dome. Some surgeons prefer to preserve the natural patella if possible, but sometimes the decision will need to be made during the operation.