High-trauma Fractures In Older Adults Linked To Osteoporosis, Increased Risk Of Another Fracture

"... it is widely believed, without supporting evidence, that high-trauma fractures [those resulting from motor vehicle crashes or falls from greater than standing height] are not related to low bone mineral density (BMD) or subsequent fracture risk and therefore are presumed not to be manifestations of osteoporosis," the authors write. They add that these beliefs have several consequences, including the clinical opinions that an older adult who has a high-trauma fracture does not require evaluation for osteoporosis, and that high-trauma fractures cannot be prevented by osteoporosis treatments that increase BMD and bone strength.

Dawn C. Mackey, M.Sc., of the San Francisco Coordinating Center, San Francisco, and colleagues examined the association between BMD in older adults and risk of high-trauma fracture and the association between this type of fracture and risk of a subsequent fracture. The researchers analyzed data from two U.S. studies of adults 65 years or older from geographically diverse areas. The Study of Osteoporotic Fractures followed-up 8,022 women for 9.1 years (1988-2006), and the Osteoporotic Fractures in Men Study followed-up 5,995 men for 5.1 years (2000-2007).

Hip and spine BMD were assessed by dual-energy x-ray absorptiometry (an imaging technique). New nonspine fractures were confirmed by x-ray. Fractures were classified as high trauma or as low trauma (due to falls from standing height and less severe trauma). Overall, 264 women and 94 men sustained an initial high-trauma fracture and 3,211 women and 346 men sustained an initial low-trauma fracture.

The researchers found that low BMD was associated with an increased risk of high- and low-trauma fracture. After adjusting for age, each 1-standard deviation (SD) decrease in total hip BMD was associated with a 45 percent increased risk of high-trauma fracture in women and a 54 percent increased risk in men. Similarly, after adjusting for age, a 1-SD decrease in total hip BMD was associated with a 49 percent greater risk of low-trauma fracture in women and a 69 percent greater risk in men.

After adjusting for age and total hip BMD, women who sustained a high-trauma fracture had a 34 percent greater risk of a subsequent fracture than women who had not experienced a high-trauma fracture. Similarly, women who sustained a low-trauma fracture had a 31 percent greater risk of a subsequent fracture than women who had not experienced a low-trauma fracture.

"In conclusion, BMD was strongly associated with high-trauma nonspine fractures in older women and men, and high-trauma nonspine fractures predicted subsequent fractures to the same extent as low-trauma nonspine fractures in women. Therefore, we concluded that high-trauma nonspine fractures should be considered potential osteoporotic fractures and should receive similar clinical management as low-trauma nonspine fractures," the authors write.

Journal reference: JAMA. 2007;298(20):2381-2388. 

Editorial: High-Trauma Fractures and Bone Mineral Density

In an accompanying editorial, Sundeep Khosla, M.D., of Mayo Clinic, Rochester, Minn., comments on the study in this week's JAMA on high-trauma fractures.

"The study by Mackey et al clearly demonstrates that the current definition of high-trauma fracture is not particularly useful. Until a better definition of fractures unrelated to BMD 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. In addition, these fractures should be included as end points in clinical trials involving prevention or treatment of osteoporosis."

Reference for editorial: JAMA. 2007;298(20):2418-2419.