Last updated: 11/24/2009

Between 200,000 and 300,000 hip replacement operations are performed in the United States each year, most of them in patients over the age of 60. According to the American Academy of Orthopaedic Surgeons (AAOS), only 5–10% of total hip replacements...

as of 2002 were in patients younger than 50. There are two reasons for this concentration in older adults. Arthritis and other degenerative joint disorders are the most common health problems requiring hip replacement, and they become more severe as people grow older. The second reason is the limited life expectancy of the prostheses used in hip replacements. Because THR is a complex procedure and requires a long period of recovery after surgery, doctors generally advise patients to put off the operation as long as possible so that they will not need to undergo a second operation later to insert a new prosthesis.

This demographic picture is changing rapidly, however, because of advances in designing hip prostheses, as well as changes in older Americans' rising expectations of quality of life. Many people are less willing to tolerate years of pain or limited activity in order to postpone surgery. In addition, hip prostheses are lasting longer than those used in the 1960s; one study found that 65% of the prostheses in patients who had had THR before the age of 50 were still intact and functioning well 25 years after the surgery. A larger number of hip replacements are now being done in younger patients, and the operation itself is being performed more often. One expert estimates that the annual number of hip replacements in the United States will rise to 600,000 by 2015.