Every year there are about 750000 knee replacements and 330000 hip replacements in the US.
A damaged joint can be replaced with an artificial one. This is often referred to as an arthroplasty. This replacement may be the entire joint or just part (one side) of one. This procedure is done more often for people with osteoarthritis or other joint diseases. These procedures cost from $16000-32000
A total knee replacement is a procedure where the two ends of the knee are replaced my metal or plastic parts. This is done when the knee has severe arthritis or a severe injury. A total knee should last 10-20 years, although they may break down earlier than that.
A total hip replacement affects the ball and socket of the hip, at the top of the upper leg bone (the femur) and the pelvis. Most hip replacements function for more than 10-20 years.
A total shoulder replacement replaces the top of the upper arm bone (humerus) and the socket for the arm bone (the scapula).