Bone densitometry and histomorphometry in postmenopausal women

The noninvasive measurement of bone density (BD) using Compton spectroscopy has several advantages over absorptiometric techniques, particularly the detection of true mass density and the discrimination of trabecular from cortical bone. In a previous histomorphometric study done ex vivo, we demonstrated a correlation between BD and trabecular bone volume (BV/TV). The present study examines the applicability of this correlation to the situation in vivo in postmenopausal osteopenia by analyzing the relationship between the density of the ultradistal radius and the trabecular bone volume in transilial bone biopsy. BV/TV correlated well with trabecular bone density (TBD) (r = 0.76) and with cortical bone density (CBD) (r = 0.71). This relationship was reinforced when BV/TV was analyzed against the combination of TBD and CBD using multiple linear regression analysis (r = 0.83). The latter correlation was further enhanced when the metacarpal cortical index (CI) was included (r = 0.93). In agreement with other reports, bone mineral density (BMD) measured in the radius by single photon absorptiometry neither correlated with BV/TV nor affected the multiple correlation coefficient. These findings indicate that in postmenopausal osteoporosis, radial BD measurements constitute a novel approach for the prediction of bone mass status in the axial skeleton.