Knee replacement rates among Medicare patients have increased sharply over the past two decades, as have surgery problems and complications. At a cost of around $15,000, the strain on Medicare and other insurers is increasing.

The number of total knee arthroplasty procedures went up 162% -- 243,802 -- from 1991 to 2010 and the per capita rate rose 99% -- to 62.1 per 10,000 enrollees, according to an analysis of fee-for-service Medicare records by Peter Cram, MD, MBA, of the University of Iowa in Iowa City, and colleagues.

An accompanying editorial also cited greater demand for an active lifestyle among seniors. Obesity and osteoarthritis are key reasons for the increase.

"While there are different contributing factors, more importantly this report may be describing only the surface of what is expected to be a profound increase in knee arthroplasty over the next 30 years," warned editorialists James Slover, MD, and Joseph D. Zuckerman, MD, both of the Hospital for Joint Diseases of New York University Langone Medical Center.

"When you multiply $15,000 [per procedure] by that volume of procedures you're talking about major money even by federal Medicare standards, and this is a real challenge for the federal government," Cram said.

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