Knee replacement surgeries have more than doubled over the past two decades in the U.S. as older Americans strive to stay active later in life, a study found. Obesity may also be a factor as more people wear out their joints with excess weight.
Total knee replacement procedures rose 162% from 1991 to 2010 while the number of procedures to repair a previously implanted artificial knee joint, called revision, jumped 106%, according to research released in the Journal of the American Medical Association.
A separate study from the Mayo Clinic found that nationally the procedure is being performed on younger and more diverse patients. Mayo researchers said that the average patient age decreased by two years (down to 68) from knee replacements performed in 1990-1994 to those in 2002-2006. Comparing those same periods, the percentage of minorities increased from 8% to 9.4%.
About 600,000 total knee replacement procedures, done to relieve symptoms of severe knee arthritis, are performed each year in the U.S., costing about $9 billion annually, according to the AMA research, led by Peter Cram, associate professor of general internal medicine at the University of Iowa’s Carver College of Medicine in Iowa City.
“This information will be useful for planning for the future,” says Michele D'Apuzzo, the Mayo Clinic orthopedic surgery resident who led its study. “Total knee replacements aren't going away any time soon. We're going to be seeing younger patients undergoing this procedure, but we may also see more failures and more revisions, and physicians and medical facilities need to prepare for that.”
Increasing rates of obesity in the U.S., where two-thirds of Americans are considered overweight or obese, may also be contributing to the rise in knee replacements, Cram said. People who are obese are predisposed to arthritis, he said.
