October 11, 1985

Densitometry of Appendicular Bone in Osteoporosis

Author Affiliations

University of Wisconsin Lunar Radiation Corporation
University of Wisconsin Madison

JAMA. 1985;254(14):1906. doi:10.1001/jama.1985.03360140058025

To the Editor.—  As the initial developers of the single-photon absorptiometry (SPA) method for bone mineral assessment,1 the chief proponents of the method over the past 20 years,2 and the originators of instrumentation for its clinical implementation,3 we have been alarmed to learn of recent unsubstantiated claims by commercial interests for exceptional clinical efficacy of SPA on appendicular bone in the diagnosis and monitoring of osteoporosis.It is true that the radius is indicative of overall skeletal status and that the density of the distal radius or the os calcis in osteoporosis is on the average significantly below that of controls. However, the density reduction at these sites is less than that for spinal density.4 Moreover, radius measurements, at both midshaft and distal sites (and even trabecular bone measurements of the os calcis or from computed tomography of the limbs), cannot accurately predict the mineral density