Researchers are testing novel materials for artificial joints.
By Robert Bazell
NBC News Correspondant
Feb. 29 -- Getting older no longer means hanging up the cleats or packing away the tennis racket. But as older Americans play harder, they are also doing more damage to their knees and hips. Now, science is offering new life for those aching joints.
"OLDER PATIENTS are not only living longer, but they're living healthier. They want to be more active much later in life. And so when their joints are replaced, or when their joints are treated in some way, they're going to ask those joints to do a lot more for them than patients 20 years ago," said Dr. Thomas Einhorn, chief of orthopedic surgery at Boston University.
A machine that tests hip implants by rotating the latest material and designs through a million movements a week is yielding important new results for the 290,000 Americans who get new hips every year.
Fast facts on hip surgery
- 290,000 Americans get hip replacements each year.
- The average age of women who undergo total hip replacement surgeries is 69.6 years; the average age of men is 63.1 years.
- 67.4 percent of total hip replacement surgeries are performed on those over 65 years of age.
Source: NBC News, American Academy of Orthopaedic Surgeons
Fifty-nine-year-old Mary Kennedy expects a lot from her new hip, which was implanted last August at Massachusetts General Hospital in Boston.
"It will outlive me and that's what I wanted," Kennedy said.
Like 40 million other Americans, she suffers arthritis, the disintegration of cartilage, the substance that cushions the bones at the joint. Her arthritis became so severe she could barely walk, making a new hip her only option. So far it's working wonders.
"You feel 20 years younger, and you feel you can do anything, accomplish anything," she said.
Arthritis: the warning signs
- Pain
- Stiffness
- Swelling (sometimes)
- Difficulty moving a joint
If you have any of these signs in or around a joint for more than two weeks, see your doctor.
Source: Arthritis Foundation
Artificial joints are not new, but often they wore out in 10 or 15 years. But Kennedy's hip is made with a new plastic actually called electron beam cross-linked ultra-high molecular weight polyethylene. All those words mean it does not wear out -- at least after the equivalent of 27 years of use in the testing lab.
"We think it's liable to be viewed years from now as one of the major changes in total hip replacement surgery," said Dr. William Harris, an orthopedic surgeon at Massachusetts General.
Even with major breakthroughs in artificial joints, scientists now see a future where they will no longer need them. New discoveries should allow doctors to rebuild aging joints so well they will not need to be replaced.
Already doctors are testing cells that replace damaged cartilage and a protein paste that helps repair damaged joints.
"Our hope is that one day surgeons will be able to offer to patients procedures which will give them back their normal joints and their normal tissues, without having to have them replaced with artificial components," Einhorn said.
The goal is to one way or another eliminate the pain of arthritis that now afflicts one in three Americans over 50.
