MEASUREMENT OF BONE-MINERAL DENSITY IN OSTEOPOROTIC FRACTURES OF THE SPINE USING DUAL-ENERGY X-RAY ABSORPTIOMETRY

The authors analyzed bone mineral density (BMD) in 283 postmenopausal and senile women using dual energy x-ray absorptiometry from March 199 0 to April 1992. Bone mineral density of the vertebral body in the ost eoporotic fracture group was compared with that in the osteoporotic gr oup to investigate the correlation among BMD, age distribution, and fr acture type, and to estimate fracture threshold in the osteoporotic fr acture group. BMD decreased rapidly (10%) from 50 and 60 years of age and decreased slowly after 60 years of age; osteoporotic spine fractur es were found in 98 cases (35%); there was significant difference in B MD between the osteoporotic group and osteoporotic fracture group; the re was no spine fracture when BMD was above 1.00 g/cm(2); fracture thr eshold was 0.85 g/cm(2) at the 90th percentile; BMD in multiple spine fracture and old fracture groups was lower than in the single and fres h fracture groups and this was statistically significant. We have conc luded that when BMD decreases to less than 0.85 g/cm(2), the risk of o steoporotic vertebral fractures escalates rapidly. Postmenopausal and senile women with BMD less than this fracture threshold should receive prophylaxis for osteoporotic fracture.