Effects of raloxifene treatment on the structural geometry of the proximal femur in Japanese women with osteoporosis

The purpose of this study was to clarify the effects of 2-year treatment with raloxifene on the proximal femoral geometry among Japanese patients with osteoporosis by hip structure analysis. One hundred ninety-eight community-dwelling postmenopausal women with osteoporosis were enrolled. The structural variables were areal bone mineral density (BMD), cross-sectional area (CSA), section modulus (index of resistance to bending forces), and buckling ratio (index of cortical instability). BMD, CSA, and section modulus at the narrow neck significantly increased by 1.27, 2.67, and 3.90% at 2 years, respectively. BMD, CSA, and section modulus at the intertrochanter significantly increased by 2.55, 4.49, and 6.60% at study termination, respectively. The buckling ratio at the intertrochanter decreased by 2.36% at 1 year, but differences at 2 years became non-significant. Parameters at the shaft were qualitatively similar to those of the narrow neck and intertrochanter. The percent change of the section modulus was significantly higher than that of BMD at 2 years in all three regions. The percent changes of the section modulus is strongly correlated with the percent changes of BMD and CSA, and negative correlated with the percent changes of buckling ratio in all regions. In conclusion, Japanese osteoporotic women on raloxifene therapy have significant improvements of both BMD and geometry in the proximal femur.