THE EXCLUSION OF HIGH TRAUMA FRACTURES MAY UNDERESTIMATE THE PREVALENCE OF BONE FRAGILITY FRACTURES IN THE COMMUNITY - THE GEELONG OSTEOPOROSIS STUDY

Fractures associated with severe trauma are generally excluded hom est imates of the prevalence of osteoporotic fractures in the community. B ecause the degree of trauma is difficult to quantitate, low bone mass may contribute to fractures following severe trauma. We ascertained al l fractures in a defined population and compared the bone mineral dens ity (BMD) of women who sustained fractures in either ''low'' or ''high '' trauma events with the BMD of a random sample of women from the sam e population. BMD was measured by dual-energy X-ray absorptiometry and expressed as a standardized deviation (Z score) adjusted for age. The BMD Z scores (mean a SEM) were reduced in both the low and high traum a groups, respectively: spine-posterior-anterior (-0.50 +/- 0.05 and - 0.21 +/- 0.08), spine-lateral (-0.28 +/- 0.06 and -0.19 +/- 0.10), fem oral neck (-0.42 +/- 0.04 and -0.26 +/- 0.09), Ward's triangle (-0.44 +/- 0.04 and -0.28 +/- 0.08), trochanter (-0.44 +/- 0.05 and -0.32 +/- 0.08), total body (-0.46 +/- 0.06 and -0.32 +/- 0.08), ultradistal ra dius (-0.47 +/- 0.05 and -0.42 +/- 0.07), and midradius (-0.52 +/- 0.0 6 and -0.33 +/- 0.09), Except at the PA spine, the deficits were no sm aller in the high trauma group. Compared with the population, the age- adjusted odds ratio for osteoporosis (t-score < -2.5) at one or more s canning sites was 3.1 (95% confidence interval 1.9, 5.0) in the high t rauma group and 2.7 (1.9, 3.8) in the low trauma group. The data sugge st that the exclusion of high trauma fractures in women over 50 years of age may result in underestimation of the contribution of osteoporos is to fractures in the community. Bone density measurement of women ov er 50 years of age who sustain fractures may be warranted irrespective of the classification of trauma.