NORMAL RANGES FOR VERTEBRAL HEIGHT RATIOS AND PREVALENCE OF VERTEBRALFRACTURE IN HONG-KONG CHINESE - A COMPARISON WITH AMERICAN CAUCASIANS

We have established the normal ranges for vertebral height ratios and studied the prevalence of vertebral fracture in 481 Chinese women aged 70-79, Our results were compared with those of an American study with a similar methodology, Lateral spine radiographs centered at T8 and L 3 were taken, and the anterior, middle, and posterior vertebral height s of each vertebra from T5 to L4 were measured, The means and standard deviations (SDs) of the anterior to posterior, middle to posterior, a nd posterior to posterior vertebral height ratios were derived after t rimming the extreme values from the distribution, The Chinese had smal ler vertebral size than the American Caucasians at all levels, Moreove r, the anterior to posterior vertebral height ratios were consistently smaller in the Chinese than in the Americans from T10 onward, The mea ns of other vertebral height ratios in the Chinese were similar to the American Caucasians, but the SDs were greater in the Chinese. The pre valence of vertebral fracture was 29% in the Chinese and 25% in the Am erican Caucasians if a cut-off of 3 SD below the mean for vertebral he ight ratios was used, We conclude that population-specific means and S D should be used for defining vertebral fracture and that the prevalen ce of vertebral fracture is similar in Hong Kong Chinese and American Caucasians.