Fracture Site-Specific Deficits in Bone Size and Volumetric Density in Men with Spine or Hip Fractures

Abstract

To study the structural basis of bone fragility in men, we compared bone size and volumetric bone mineral density (vBMD) of the third lumbar vertebra and femoral neck in 95 men with spine fractures, 127 men with hip fractures, and 395 healthy controls using dual-energy X-ray absorptiometry (DXA). The results were expressed in absolute terms and age-specific SD scores (mean ؎ SEM). In controls, vertebral body and femoral neck width increased across age, being 0.46 ؎ 0.11 SD and 0.91 ؎ 0.08 SD higher in elderly men than in young men, respectively (both, p

Age trends for hip geometry in Chinese men and women and the association with femoral neck fracture

“…Rapid bone turnover and resorption of bone in the endosteal surface are accelerated during the postmenopausal period in women, which leads to thinning of the cortical envelope and weakened bone structure [21]. Although low BMD of the proximal femur predicts hip fracture risk [22][23][24], age-related loss of bone mass in the hip does not necessarily imply reduced mechanical strength [10,[25][26][27]. Subjects who have suffered a cervical fracture are reported to have a thinner cortex at the femoral neck, longer hip axis, greater NSA, and lower CSMI and SI compared with non-fracture controls [6,9,[28][29][30][31][32].…”

Heterogeneity in the Growth of the Axial and Appendicular Skeleton in Boys: Implications for the Pathogenesis of Bone Fragility in Men

“…(8) For example, in men with estrogen receptor defects or aromatase deficiency, the deficits in BMC or aBMD are greater at the spine than at the femur because VB size is reduced (relative to controls) and proximal femur size is increased (relative to controls). (22,23) vBMD depends on the relative growth in size and mass of the region, not the absolute growth of either trait.…”

“…(7) Men with VB fractures have reduced VB volume and reduced VB volumetric bone mineral density (vBMD) with more modest deficits at the femoral neck (FN), whereas men with FN fractures have reduced FN volume and reduced FN vBMD with modest trait deficits at the VB. (8) Deficits in bone size may be caused by reduced bone growth, failed periosteal expansion during aging, or both; deficits in vBMD may be caused by reduced accrual, excessive bone loss, or both. The contribution of growth-related factors is suggested by the observation that the offspring of men with fractures have reduced areal bone mineral density (aBMD) at the site of fracture in their fathers.…”

Thinking inside and outside the envelopes of bone

“…Sex differences in trabecular and cortical bone loss A greater proportion of women than men sustain fragility fractures during their lifetime because (1) men have larger skeletons than women, even after adjustment for the differences in body size, so that resistance to bending is greater in men than in women; (2) bone loss in men is the result of a negative BMU balance produced by reduced formation rather than increased resorption by the BMUs, so trabecular bone loss occurs by thinning rather than by loss of connectivity [55]; (3) men do not have a midlife decline in sex hormones and an increase in remodeling rate that drives structural decay; (4) cortical porosity increases less in men than in women because remodeling rate is lower in men; and (5) periosteal apposition may be greater in men than in women as reported in some [56][57][58][59][60], but not all [29], studies (Fig. 4).…”