March 24, 2006 (Chicago) -- The number of total knee replacements performed in the U.S. will leap by 673% -- reaching 3.48 million -- by the year 2030, according to a new study presented Friday at the 73rd annual meeting of the American Academy of Orthopaedic Surgery in Chicago.
Hip replacements will increase by 174% to 572,000 by 2030, according to the new findings, which are based on historical procedure rates from 1990 to 2003 and population projections from the U.S. Census Bureau.
"There is a huge swell of elderly patients from the baby boom who will come through the system and be candidates for artificial joints," explains researcher Steven M. Kurtz, PhD, office director and principal engineer at Exponent Failure Analysis Associates in Philadelphia.
Surgery of Last Resort
"Artificial joints are so successful and they provide such good improvements on quality of life for people with arthritis that they are getting more and more accepted and more people are more aware of them," Kurtz tells WebMD. "The more successful an operation is, the more people that want it."
Joint replacement surgeries are typically the last resort for people with osteoarthritis (OA), also known as degenerative joint disease, in which cartilage deteriorates, causing injury to the joint. People feel stiffness, pain, and loss of movement as bone begins to rub against bone. Affecting close to 21 million people, OA of the knee and hips is the most common cause of arthritis-related disability in the U.S, according to statistics from the Arthritis Foundation.
Some people with rheumatoid arthritis (RA), an autoimmune disease in which the joint lining becomes inflamed as part of the body's misguided immune system activity, may also undergo joint replacement surgery.
Joint Replacements Don't Last Forever
And the more primary joint replacements surgeries there are, the more "do-over" joint replacement surgeries there will be. Repairs of previous joint replacement surgeries are called revision surgeries. The new projections suggest that the number of revision surgeries will double by 2015 for total knee replacements, and hip replacement revisions will double by 2026.
"The flip side is that even though this is such a successful surgery, sometimes joints do need to be re-replaced," Kurtz tells WebMD.
"Patients need to be aware that while artificial joint replacements are successful, they don't last forever," he says. There is roughly a 90% chance that an artificial joint will last 10 years, "so if you are 50 or 60 when you undergo your first surgery, you should expect to undergo a revision surgery."
Kurtz suggests that demand for these surgeries may overwhelm supply. There may not be enough orthopaedic surgeons to keep pace with the demand for new joints. "If the massive expected demand for total joint replacement is not planned for before 2030, patients may end up waiting a long time for a new hip or knee."
Amar S. Ranawat, an orthopaedic surgeon at Lenox Hill Hospital in New York City, is expecting to see a growing number of people who need joint replacement surgery in the coming years.
"The baby-boomer population is increasing. And if you think of arthritis as a percentage of the population, then as the population increases, there will be more disease. So there will be more primary arthroplasty, which will lead to more revision arthroplasty," he tells WebMD. Arthroplasty is the technical name for joint replacement surgery.
"People are getting surgeries earlier on in the disease process, and when you undergo your first operation in your 50s, there is an increased risk of having another in your 60s or 70s," he says.
As to whether there will be a shortfall of available orthopaedic surgeons to do all the replacement operations, Ranawat says that "there are a lot of orthopaedic surgeons in major cities that can accommodate the increase, but there may be a shortfall in local, smaller communities, so more people will be going toward major cities to get the operation."