Improved vertebral fracture threshold in postmenopausal osteoporosis by radiogrametric measurements: its usefulness in selection for preventive therapy.

Measurements of the combined cortical thickness at the midshafts of the second metacarpal and the proximal radius, as well as their sums, were made from fine-grained radiographs in 107 normal premenopausal and 227 postmenopausal women and in 57 women with at least two spontaneous vertebral compressions. The -2 SD level of the premenopausal women was found to be an excellent vertebral fracture threshold for the radius measuring site and for the sums of metacarpal and radial measurements. Only 2 of 57 (4%) and 3 of 57 (5%), respectively, of values in the vertebral compression group fell at or above this level. At -3 SD a "secondary fracture threshold" was found for the sums in that only 7 of 57 (12%) of values in women with vertebral compressions were above this limit, but -3 SD was less satisfactory for the radius. We conclude that this method discriminates as well between nonfracture and fracture cases as other radiologic methods for measurement of bone mass or density. Because it is less costly it seems better suited for mass screening in selecting postmenopausal women for preventive therapy than the less widely available high-technology methods.