Age-related changes in mechanical indices of compact bone tissue
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The mechanical indices of demineralized compact bone tissue upon tensile testing change with age. The greatest linear correlation was found for the initial modulus of elasticity E1 (r = 0.87). The mean tangential modulus of elasticity over the cross section doubles from age 24 to 52. The greatest linear correlation with age for strength indices is found for ultimate deformation ɛ11* (r = -0.94). Its mean value over the cross section decreases by a factor of 1.52.
The outer layer has higher mean strength indices and initial moduli of elasticity over the cross section, More regular and significant correlations with age are also found for the outer layer for all deformation and most strength indices. It is assumed that these differences in the age-related changes in the mechanical indices of the organic matrix over the thickness of the cortical layer of bone are mainly the result of structural nonuniformity.
The rate of change of the mechanical indices of demineralized compact bone tissue upon aging is nonuniform over the cross section. Biological aging has the greatest effect on the change in E1 and ɛ11* in zone 6 which, under normal physiological loads, functions primarily in tension.
KeywordsTensile Testing Linear Correlation Bone Tissue Outer Layer Biological Aging
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