EVALUATION OF TIBIAL CORTICAL BONE BY ULTRASOUND VELOCITY IN ORIENTALFEMALES

In order to evaluate the feasibility of detecting bone status by measu ring cortical ultrasound velocity, ultrasonic transmission velocity of the anterior cortex of shin was measured on 175 normal Chinese female s aged 31-75 years (mean 52.3+/-SD 9.1 years). The data were compared with bone mineral density (BMD) of the lumbar spine and/or hip measure d by dual energy X-ray absorptiometry (DXA), which was performed on th e same day as speed of sound (SOS) examination. Comparison was made wi th SOS elf Caucasian women previously reported in the literature. SOS of three volunteers measured by two different operators were also enro lled in our study for precision testing. The mean value of SOS of the 175 females was 3850.7+/-119.3 ms(-1) (range: 3411.7-4220.5 ms(-1)), t he peak value being in the fourth decade. The rate of decrease of tran smission velocity per decade from fourth decade to fifth decade was 1. 7%, while that of fifth decade to sixth decade was 2.2% and that of si xth decade to seventh decade was 4.0%. The interoperative and intraope rative coefficient variance with and without reposition were under 0.3 2%. SOS moderately correlated with BMD at different sites, the best co rrelation being with the lumbar spine anteroposterior projection (r = 0.509; p < 0.0001, Pearson's test). There were significant differences in SOS between pre-and post-menopausal groups (p = 0.01, ANOVA test), and between peri-and post-menopausal groups (p=0.02), but there was n o correlation of body weight and height with SOS. SOS also inversely c orrelated with age and post-menopausal duration. The mean value of SOS in out-study was similar to that of Caucasians, but the rate of decre ase over 50 years of age was faster. The rate of decline of tibial cor tical SOS was similar to that of trabecular bone as previously reporte d in the literature. As there is a significant decrease of SOS in olde r females, and older Oriental females suffer from an accelerated corti cal bone loss, it is concluded that cortical bone SOS may be a useful method for detecting potential osteoporotic patients in this ethnic gr oup.