Any old broken bone could mean osteoporosis

No matter the circumstances, if you're 65 or older and break a bone, your risk of having osteoporosis and suffering more fractures is greater than that of someone who has yet to break a bone after his 65th birthday, scientists report today.

Their finding contradicts the widely held belief that only bones broken in a fall from a standing height or lower are related to the bone-thinning disease osteoporosis. Bones broken in falls from greater heights or in car crashes, so-called high-trauma fractures, don't count as red flags for osteoporosis, although there is little scientific evidence to support that view.

One of the main problems is that the concept of high trauma is fuzzy, says lead author Dawn Mackey. The magnitude, velocity and direction of the force applied to bone can vary from car crash to car crash and fall to fall, so the impact on bone of low-speed collisions isn't necessarily greater than the impact on bone of slipping on ice and hitting the pavement, Mackey's team writes. Yet the former is generally considered high trauma, while the latter is not.

The researchers analyzed data from two studies. One followed 8,022 women for about nine years; the other followed 5,995 men for about five years. All were at least 65 at the start.

Overall, 264 women's and 94 men's first broken bones were considered to be high-trauma fractures, while 3,211 women's and 346 men's first broken bones were low-trauma ones.

Whether their first fractures were high or low trauma, women who'd broken a bone were about a third more likely to sustain another fracture during the course of the study than women who did not have an initial fracture. In addition, the scientists write in the Journal of the American Medical Association, women who sustained either high-trauma or low-trauma fractures were equally likely to have low bone-mineral density, considered the gold standard for diagnosing osteoporosis.

Although there were too few fractures among the men to quantify the risk of another fracture, the authors observed similar trends.

But the presumption, Mackey says, has been that anyone, weak bones or not, could suffer a fracture in a car crash or a fall from a ladder. When you break a bone in that kind of an accident, you've earned it, or so many doctors believe, says Mackey, an epidemiologist at the California Pacific Medical Center Research Institute in San Francisco.

As a result, she says, older people who have a high-trauma fracture don't receive the same sort of workup for osteoporosis that, say, peers who slip on the ice and break a hip do. Doctors don't think osteoporosis drugs can prevent high-trauma fractures. And clinical trials of drugs designed to treat osteoporosis may be overlooking valuable information by ignoring such fractures.

"Fractures previously defined as due to high trauma, such as those from a blunt injury in a motor vehicle crash or a fall from a chair, can no longer be dismissed as being unrelated to osteoporosis," Mayo Clinic osteoporosis researcher Sundeep Khosla writes in an accompanying editorial.

Source: http://www.usatoday.com/news/health/2007-11-27-osteoporosis_N.htm?csp=34