Medicare patients living in rural areas are more likely to get total knee replacement and total hip replacement than their counterparts who live in cities, according to a new study published in the December issue of Arthritis & Rheumatism.

The finding is a surprise to researchers at Southern Illinois University School of Medicine, who say they started this study expecting that people living in rural areas would be less willing or able to have these procedures done, whether it was because of cost or the simple fact that they lived farther from hospitals. Their study found the opposite.

Scientists studied the 2005 medical records of close to six million rural Medicare beneficiaries and nearly 38 million urban recipients. From that pool, they identified patients who had their first total joint replacement surgery. They discovered that 1.02 percent of rural residents had a total knee or hip replacement, making them 27 percent more likely to have one of their joints replaced than city patients, 0.80 percent of whom had the surgery.

“It has caused us to take a step back and look at things. We don’t know the full explanation for why it is. That will take further research to understand that,” says Mark Lee Francis, MD, Chief of the Division of Rheumatology at Southern Illinois University School of Medicine in Springfield, Ill. “It could be that people who live in rural areas have more arthritis than others because of what’s happening with their jobs or occupations. It’s possible that people in rural areas need to have functioning legs to do their activities more than people in urban areas; so even with the same amount of arthritis they’re more likely to have surgery. “

“One thing we cannot answer with what we’ve done so far is, we cant say whether there is an over utilization of these surgeries in rural areas or if there’s an underutilization in urban areas,” Dr. Francis adds.

Researchers found women were more likely than men to have total joint replacement surgeries. Men were 31 percent less likely in rural areas to have joint replacement surgery and 33 percent less likely in urban settings. But since more women have arthritis, scientists say it is likely that men with arthritis had the surgery more frequently than women.

The research team also found that minorities opted for the procedure less often than whites did. But those differences were smaller in rural settings. For example, Hispanics in rural areas were as likely as whites to get joint replacements.

Researchers concluded that lack of access to a hospital for these procedures does not seem to be an issue. Patients appear more willing than ever to travel, if necessary, to have elective surgery.

“It appears the people who want to have it done, can. It could be that once you have the pain and loss of function, you’ll find a way to get it done,” Dr. Francis says. “We don’t know why it’s more in rural areas. That’s an unexpected finding and we’re going to try and figure out what’s going on with that."