WASHINGTON — The severity of vertebral fractures increases significantly in patients whose trabecular bone volume falls below the critical value of 15%, Harry K. Genant, M.D., said in his oral presentation of a poster at an international symposium sponsored by the National Osteoporosis Foundation.
Dr. Genant, a member of the Osteoporosis and Arthritis Research Group at the University of California, San Francisco, and his colleagues assessed the bone quality of 190 postmenopausal women, mean age 69 years, using radiographic data from 2-D histomorphometry and 3-D microCT.
The women were categorized into four groups based on varying severity of vertebral fractures, with 0 meaning “no fracture,” and 1, 2, and 3, relating to mild, moderate, and severe fracture levels, respectively.
Based on the radiographic data, patients in the moderate and severe fracture groups had significantly reduced 2-dimensional trabecular bone volumes (0.15 and 0.13, respectively), compared with patients who had no fractures (0.20). On further analysis of the radiographs, the researchers found that as the severity of vertebral fractures grew worse, patients had progressively worse bone quality based on measurements including trabecular separation, trabecular number, and 3-dimensional trabecular bone volume.
These results are consistent with earlier findings that patients are at significantly increased risk of fracture when the trabecular bone volume falls below approximately 15%. Dr. Genant has received grants and research support, as well as an honorarium, from Eli Lilly & Co.