The knee joint is made up of three bones, the top is the thigh bone (femur), below is the skin bone (tibia), and the front is the knee cap (patella). They move and work together to ensure a smooth motion and function of the knee.

Total knee replacement (TKR) is an operation which involves replacement of the damaged bearing surfaces in the knee that causes pain and decrease the normal motions and functions of the knee joint. TKR involves resurfacing the knee joint with an artificial joint made of metal and plastic. There are usually three components – femoral prosthesis, tibial prosthesis and patellar prosthesis. The materials used are very strong and are designed to last a reasonably long time inside the body. TKR is a common procedure and the replacement should last around 15-20 years.

The hip joint is a large ball and socket joint. The cup side of the joint is known as the acetabulum and the ball side as the head of femur. Total hip replacement consists of acetabulum cup, ball head and femoral stem. They are usually made of metal alloy, polyethylene or ceramic. If one or both of your hip joints are damaged, your doctor may recommend you to have this operation.