Biomedical Engineering Reference
In-Depth Information
Table 5
Gender dependence of collagen crosslinks in human cortical bone [
117
]
HP
LP
PE
Female-middle [ Male-middle
Female-middle [ Male-middle
Female-middle \ Female-old
Female-old [ Male-old
Female-old [ Male-old
Male-middle \ Male-old
Female-middle [ Female-old
Male-middle [ Male-old
remodeling which results in less crosslinked collagen and/or due to decreased
enzymatic activity of lysyl oxidase with age [
117
]. In addition, the amount of non-
enzymatic crosslinking (pentosidine [PE]) increased from middle-age to elderly in
both women and men. Gender effects were small, with slightly increased HP and LP
in women (Table
5
)[
117
]. Notably, differences between osteonal and interstitial
tissues were greater than those induced by age- or gender. Finally, the increased
variability of shrinkage temperature of the collagen network in bone may be gender-
dependent, decreasing markedly with age in men, but not women [
145
].
5.2 Gender Differences in Mechanical Properties
of Cortical Bone
There is limited information regarding the effect of gender on tissue properties of
human cortical bone. An early study reported no significant differences in the
mechanical properties of cortical bone between males and females, in which the
bone specimens from human femora and tibiae were tested in tension, torsion, and
compression for a population ranging in age from 20 to 86 years [
60
]. In addition,
a more recent study observed that bone matrix apparent stiffness was not signifi-
cantly different between males and females for femoral cortical bone [
146
].
Moreover, a fracture toughness study of human cortical bone indicates that tissue
toughness gradually decreases with age between 55 and 89 years old and no
significant differences in the toughness of bone exist between men and women
[
147
]. Thus, available evidence suggests that gender per se may not have signif-
icant effects on the tissue properties of cortical bone.
References
1. Martin, R.B., Ishida, J.: The relative effects of collagen fiber orientation, porosity, density,
and mineralization on bone strength. J. Biomech. 22(5), 419-426 (1989)
2. Jackson, S.A.: The fibrous structure of bone determined by x-ray diffraction. J. Biomed.
Eng. 1(2), 121-122 (1979)
3. Bembey, A.K., et al.: Contribution of collagen, mineral and water phases to the nanomechanical
properties of bone. In: Fundamentals of Nanoindentation and Nanotribology III, Symposium,
29 Nov.- 3 Dec. 2004, Materials Research Society, Boston, 2005
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