AARP Home » Health » Conditions & Treatments »8 Key Facts About Knee...

8 Key Facts About Knee Replacement Surgery

Will these new knees hold up?

by: Beth Levine | from: AARP Bulletin | March 1, 2011

En español | Lloyd Emanuel, a 62-year-old tennis pro from Rye, N.Y., had been playing competitively for 50 years — and hoped to keep going. Six years ago, however, the pain started in his right knee. The diagnosis: osteoarthritis, the breakdown of joint cartilage. An orthopedic surgeon repaired the torn cartilage, and — despite the doctor's warnings to slow down — Emanuel kept playing tennis full out. Three years later, he was back on the operating table, being prepped for a total knee replacement.

— Mirko Ilic

More and more boomers are opting for knee replacement surgery earlier in life. The reason? Boomers like Emanuel are more active than any previous generation — and want to run, dance and play basketball and, yes, tennis at the same level of intensity as they did in their 20s.

Previously, knee replacement surgeries were reserved for very old patients who were severely crippled by osteoarthritis. "Now patients in their 40s and 50s are experiencing an earlier onset of osteoarthritis that affects their daily lives," says J. David Blaha, M.D., an orthopedic surgeon at the University of Michigan Health System. In fact, the number of boomers opting for early knee replacement is growing at a dramatic rate.

According to the American Academy of Orthopaedic Surgeons (AAOS), the total number of knee replacements performed each year, both total and partial, rose 30 percent from 2004 to 2008. In that same period, there was a whopping 61 percent increase in these surgeries among men and women ages 45 to 64. And that increase is expected to continue and even grow as boomers age. In 10 years, experts estimate, there could be as many as 3.2 million knee replacement surgeries each year, says Blaha.

What concerns orthopedic surgeons is that because joint replacements have been performed primarily on older patients, there isn't a lot of data to show how these implants hold up in younger people who will have them over longer periods of time.

"We use new and better materials and techniques, so we think there is an improvement in the longevity, but we still don't know. The new plastics have only been out there for three years," says Rafael J. Sierra, M.D., an orthopedic surgeon at the Mayo Clinic. The AAOS has announced the creation of the American Joint Replacement Registry to monitor replacement outcomes.

Younger knee replacement patients may need to get a new replacement in as little as five to 10 years, which is a concern. "It gets more complicated with each revision," says Michael R. Baumgaertner, M.D., professor of orthopedic surgery at Yale University School of Medicine. "Every time it has to be redone, there is more bone loss."