More than 90 percent of individuals who undergo total knee replacement surgery experience a dramatic reduction of knee pain and a significant improvement in the ability to perform daily activities. Following surgery, you will be advised to avoid some types of activity, including jogging and high impact sports. With normal use and activity, every knee replacement develops some wear in its plastic cushion. Excessive activity or weight may accelerate this normal wear and cause the knee replacement to loosen and become painful. With appropriate activity modification, knee replacements can last for many years.