人体腰椎松质骨的生物力学性质

BIOMECHANICAL CHARACTERS OF HUMAN LUMBAR VERTEBRAL TRABECULAR BONE

本文以三具新鲜男性尸体的Ｔ１２～Ｌ４椎体的松质骨为材料，通过准静态压缩试验，分析了应变率（ε）表观密度（ρａ）和组织密度（ρｔ）对松质骨弹性模量、强度和终应变的影响。试验采用了５个应变率１．０×１０－５，５．０×１０－５，１．０×１０－４，５．０×１０－４，１．０×１０－３Ｓ－１。松质骨的表观密度和组织密度范围分别为０．４６～０．７１ｇ／ｃｍ３，１．０２～１．５４ｇ／ｃｍ３。以弹性模量、强度和终应变为因变量（Ｙ），以应变率和表观密度或组织密度为自变量。利用以下模型进行了非线性回归分析：Ｙ＝ａρｂａεｃ。当ｂ分别取１．８８，２和３时，弹性模量与应变率的关系均可用上面模型表达，其指数ｃ分别为０．０７，０．１，０．１。弹性模量与表观密度呈１．８８次方关系，强度与表观密度呈１．２９次方关系。终应变作为独立变量不受表观密度和应变率的影响。

he effect of strain rate(ε), apparent density (ρa) and tissue density (ρt) on Young's Modulus (E), strength (σu) and ultimate strain(εu) was studied in 36 human trabecular bone specimens of T12～L1vertebra of 3 male cadavers. Testing was performed on INSTRON (Model 1186) by uniaxial compressio density ranged between 0.46 and 0.71g/cm3. Tissue density ranged between 1.02 and 1.54g/cm3. Using Young's modulus strength, or ultimate strain as dependent variables (Y) and strain rate and apparent density or tissue density as independent variables nonlinear regression analyses were performed using the following model: Y=aρbc. The variation of Young's modulus was explained well by all these relationships to strain rate. The exponent was 0.07, 0.1, 0.1 in each model between Young's modulus and strain rate. The variation of strength was explained only by apparent density with an exponent of 1.29. The variation of Young's modulus was explained equally by quadratic and cubic relationship to apparent density or tissue density. Ultimate strain varied independently of apparent density or tissue density and strain rate.