Knee Replacement Surgery For Seniors Soars

The rate of older adults getting  knee-replacement surgery has more than doubled in the past 20 years, a new study finds, but the surgery's popularity has also led to increased rates of postsurgery infections and complications.

The study, published last week in the Journal of the American Medical Association, looked at more than 3 million Medicare patients 65 or older who got artificial knees from 1991 through 2010. The annual rate of initial knee-replacement surgeries jumped from 31 per 10,000 Medicare beneficiaries in 1991 to 62 per 10,000 in 2010.

By 2010, nearly 244,000 seniors had undergone the operation. (About 600,000 knee-replacement surgeries are performed annually nationwide on adults of all ages.)

According to the Associated Press, patients in the study were in their mid-70s, on average, when they had the surgery - and that age edged up during the study.

Obesity, which puts pressure on joints and can lead to arthritis, also played a role: The rate of obese older patients getting their first knee replacement tripled, from 4 to 12 percent in the past two decades, the study found.

While artificial knees - and the operations to implant them - have improved, the study found other worrisome developments. "The most concerning complication is the increase in readmissions for infection," the study's authors wrote, rising to 3 percent from 1.4 percent two decades ago.

This may be partly because financial pressures have forced hospitals to slash the time people spend recovering there from eight days to just three and a half. Rushing patients out of the hospital to rehab centers may have led to "less vigilance" in watching for signs of wound infection, the researchers wrote.

The price of knee-replacement surgery is also a concern. The procedure costs an average of $15,000 per patient, and a JAMA editorial called for measures to control costs, especially because demand is expected to rise to almost 4 million knee operations annually by 2030.

In other health news:

This year's flu vaccine guards against two new strains. Last year's flu shot won't shield you this year, the Associated Press reports. Two new strains of influenza have begun circling the globe, and the updated vaccine appears to work well against them, government officials said last week.

Antibiotics prescribed more often for seniors in the South. The New York Times reports on a new study that finds that older men and women in the South are prescribed antibiotics more often than older Americans in other parts of the country,  even though there is no evidence that the South has higher rates of pneumonia and other diseases for which antibiotics are necessary.

Photo: National Institutes of Health