High-impact fracture risk tied to osteoporosis

By Anthony J. Brown, MD

NEW YORK (Reuters Health) - Contrary to popular belief, high-trauma fractures, such as those seen with vehicle accidents or falls from high heights, are associated with osteoporosis in older adults, new research suggests.

A high-impact event, the argument went, is likely to cause a fracture regardless of a person's bone density, but this is apparently not the case.

"Physicians and researchers have thought that only some fractures (i.e., those resulting from seemingly low-trauma events such as falls from standing height) are related to osteoporosis," Dawn C. Mackey told Reuters Health. "We have shown that all fractures, including those that result from seemingly high-trauma events, are related to osteoporosis."

Mackey, from the California Pacific Medical Center Research Institute in San Francisco, and colleagues examined the link between bone mineral density and high-impact fractures in more than 8000 older women followed for 9 years and in nearly 6000 older men followed for 5 years.

In women, with each standard unit drop in bone mineral density the risk of high-trauma and low-trauma fractures increased 45 percent and 49 percent, respectively. In men, the corresponding values were 54 percent and 69 percent, the team reports in this week's Journal of the American Medical Association.

The "results were not surprising because it is inherently difficult to quantify and define high trauma when we do not know the magnitude of forces applied to the bone during a fracture event," Mackey commented.

The study "clearly demonstrates that the current definition of high-trauma fracture is not particularly useful," Dr. Sundeep Khosla, from the Mayo Clinic in Rochester, Minnesota, writes in a related editorial. "Until a better definition of fractures unrelated to bone mineral density is developed, older patients sustaining high-trauma fractures cannot be ignored in terms of their skeletal status, and they should be evaluated more thoroughly for underlying osteoporosis."

SOURCE: Journal of the American Medical Association, November 28, 2007.