Sex Differences of Human Trabecular Bone Microstructure in Aging Are Site-Dependent

Abstract

In this study, we characterize bone microstructure, specifically sex differences, at multiple skeletal sites in 165 subjects >52 yr of age, using µCT technology in vitro. Significant sex differences are observed at the distal radius, femoral neck, and femoral trochanter, but not at the iliac crest, calcaneus, and lumbar vertebral body. Correlations in BV/TV between sites ranged from r = 0.13 to 0.56. Introduction:The goals of this study were (1) to assess potential sex differences of bone microstructure and their difference between skeletal sites and (2) to explore the relationship of trabecular microstructural properties between relevant skeletal sites. Materials and Methods: Trabecular bone microstructural properties were measured in vitro in 165 subjects 52-99 yr of age using CT. Defined volumes of interest (cylinders with 6 mm diameter and 6 mm length) were scanned at a resolution of 26 m (isotropic) in six different anatomical sites: distal radius, femoral neck and trochanter, iliac crest, calcaneus, and second lumbar vertebral body. Results: At the radius and femoral neck, trabecular bone displayed a more plate-like structure, thicker trabeculae, smaller separation/higher trabecular number, higher connectivity, and a higher degree of anisotropy in men than in women (p < 0.05). At the trochanter, men displayed more plate-like structure and thicker trabeculae (p < 0.05), but no differences in trabecular separation or other parameters compared with the women. At the calcaneus, iliac crest, and second lumbar vertebra none of the bone parameters displayed significant differences between sexes. The BV/TV at one site explained a range of only 2-32% of the variability at other sites. Conclusions: These results suggest that trabecular bone microstructural properties are remarkably heterogeneous throughout the skeleton. Significant differences between men and women are observed at some, but not at all, sites. The magnitude of sex differences in trabecular microstructure coincides with that of fracture incidence observed for some of the sites in epidemiological studies.

The Effect of the Achilles Tendon on Trabecular Structure in the Primate Calcaneus

“…We were only able to observe this in gibbons, as the other taxa either did not have enough specimens of both sexes, or the sex was unknown. We suggest that the difference in trabecular properties between the sexes may play a role in the substantial intraspecific variation (Hudelmaier et al, 2005;Eckstein et al, 2007). Though our volumes of interest were chosen to specifically isolate trabeculae that would be most impacted by the Achilles, there is a possibility that these VOIs were not in the correct locations or the correct size.…”

Bone three-dimensional microstructural features of the common osteoporotic fracture sites

“…Cancellous bone specimen of 8 mm × 8 mm × 8 mm cube was prepared from the central part of femoral neck for quantitative micro-CT examination. Alterations of the femoral neck cancellous bone with advancing age include a decline in BV/TV and Tb.N, and an increase in Tb.Sp [49,51,52] . BV/TV decreases by around 20% from 60 to 90 years of age (Figure 4).…”

Influence of the shape of the micro-finite element model on the mechanical properties calculated from micro-finite element analysis

“…A limitation of the present study was that the trabecular bone specimens used in our study were collected from vertebral bodies. It has is well-documented that the morphologies of trabecular bone harvested from different skeletal sites are quite different (34,35). Further research is required to confirm that the findings of the present study are applicable to other skeletal sites.…”