The increasing use of peripheral bone densitometry

Better at assessing fracture risk than diagnosing osteoporosis

Osteoporotic fractures are a major cause of excess mortality, morbidity, and expenditure worldwide. There is a strong inverse relation between bone mineral density and the risk of fracture, with a doubling in fracture incidence for each standard deviation reduction in bone mineral density.1 The World Health Organization has defined osteoporosis as a bone mineral density of more than 2.5 standard deviations (T score <−2.5) below the mean value for young adults.2 This definition was made for epidemiological reasons to compare female populations and not as a threshold for intervention. However, the WHO definition has been used increasingly for the diagnosis of osteoporosis in individuals, based on the measurement of bone mineral density at the hip and spine using dual energy x ray absorptiometry. Recently, newer peripheral densitometry devices have been developed, which have the advantage of low cost and portability. It is likely that these will be used increasingly for the diagnosis of osteoporosis and assessment of fracture risk in the community.

The commoner forms of these devices in Europe and North America include heel and forearm dual energy x ray absorptiometry and quantitative ultrasound at the heel. The various devices have similar overall predictive value for estimating fracture risk regardless of the …