Proximal femur geometry assessed by hip structural analysis in hip fracture in women

In the pathogenesis of hip fracture, proximal femur geometry plays a key role as well as decreased bone density. The hip structural analysis (HSA) processes dual energy X-ray absorptiometry (DXA) images containing information on the geometry closely related to the strength of the proximal femur. The objective of this study was to investigate bone mineral density (BMD) and mechanical properties of the proximal femur in a group of women with a previous contralateral hip fragility fracture compared to women without history of hip fracture.

In a population of postmenopausal women, we evaluated bone density by DXA and bone geometry using the HSA parameters (femoral strength index, cross-sectional moment of inertia, cross-sectional area, section modulus, and buckling ratio) including hip axis length (HAL) and neck shaft angle.

Of a total of 62 postmenopausal women, twenty-six with a history of hip fracture had a mean femoral neck BMD significantly lower in comparison with 36 women in the control group (0.703 versus 0.768 g/cm(2), p = 0.0347). There was a statistically significant difference between groups also for HAL (106.75 mm in fracture group versus 100.93 mm in control group, p = 0.0015).

Our results demonstrated that all the geometrical parameters resulted worst into the group of patients with history of hip fracture, even though only the HAL was significantly lower in control subjects. In our opinion HSA is useful to characterize the risk of hip fracture in postmenopausal women, providing additional data on the spatial distribution of bone mass strongly related to bone strength.