As of 1980, approximately 1,800,000 people reached the age of 65 each year in the United States. It may be estimated that each year 35,000 of these people would benefit from total hip replacement surgery and are medically fit for it. Numbers for knee replacement are similar. Other joint replacements are much less in number but may be equally done when indicated. With the constant improvement of surgical technique, prostheses, and medical expertise, these people can be offered significant improvement in the quality of life by replacement of painful disabling joints.