Measurement of bone mineral density in osteoporotic fractures of the spine using dual energy X-ray absorptiometry.

Abstract

The authors analyzed bone mineral density (BMD) in 283 postmenopausal and senile women using dual energy x-ray absorptiometry from March 1990 to April 1992. Bone mineral density of the vertebral body in the osteoporotic fracture group was compared with that in the osteoporotic group to investigate the correlation among BMD, age distribution, and fracture type, and to estimate fracture threshold in the osteoporotic fracture group. BMD decreased rapidly (10%) from 50 and 60 years of age and decreased slowly after 60 years of age; osteoporotic spine fractures were found in 98 cases (35%); there was significant difference in BMD between the osteoporotic group and osteoporotic fracture group; there was no spine fracture when BMD was above 1.00 g/cm2; fracture threshold was 0.85 g/cm2 at the 90th percentile; BMD in multiple spine fracture and old fracture groups was lower than in the single and fresh fracture groups and this was statistically significant. We have concluded that when BMD decreases to less than 0.85 g/cm2, the risk of osteoporotic vertebral fractures escalates rapidly. Postmenopausal and senile women with BMD less than this fracture threshold should receive prophylaxis for osteoporotic fracture.