Longitudinal elastic properties and porosity of cortical bone tissue vary with age in human proximal femur
Longitudinal elastic properties and porosity of cortical bone tissue vary with age in human proximal femur
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DOI：
10.1016/j.bone.2013.01.015
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发表时间：
2013-04-01
期刊：
影响因子：
4.1
通讯作者：
Raum, K.
中科院分区：
文献类型：
--
作者：
Malo, M. K. H.;Rohrbach, D.;Raum, K.
组织水平的结构和力学性能是骨强度的重要决定因素。随着个体年龄的增长，骨骼中发生微观结构变化，例如，骨小梁和皮质变薄，孔隙度增加。然而，目前尚不清楚骨骼的弹性在老化过程中如何变化。随着年龄的增长，骨组织可能会失去弹性，变得更脆，更容易骨折。在本研究中，使用声学显微镜的人类股骨颈和股骨干的微观结构和微弹性性能的空间分布的年龄依赖性变化进行了评估。虽然这些属性可能无法直接测量在体内，有一个主要的兴趣，以调查他们的关系与线弹性测量获得的诊断超声在最严重的骨折部位，如股骨颈。然而，在建立新的体内技术的有效性之前，必须了解不同骨骼部位组织弹性特性和孔隙率的年龄依赖性变化。从21名男性（平均SD年龄47.1 +/- 17.8，范围17-82岁）的股骨颈（Fn）和股骨干近端（Ps）共获得42个横截面骨样本。使用配备有50 MHz超声换能器的扫描声学显微镜（SAM）对样品进行定量成像。测定了皮质（Ct）和小梁（Tr）组织的弹性系数（c（33））的分布以及皮质的显微结构（皮质厚度Ct、Th和孔隙度Ct、Po）。观察到c（33）的变化与组织类型（c（33）Tr c（33）（Ct.Fn）= 35.3 GPa > c（33）（Tr.Ps）= 33.8 GPa>c（33）（Tr.Fn）= 31.9 GPa）和尸体年龄（R-2= 0.28-0.46，p
Tissue level structural and mechanical properties are important determinants of bone strength. As an individual ages, microstructural changes occur in bone, e.g., trabeculae and cortex become thinner and porosity increases. However, it is not known how the elastic properties of bone change during aging. Bone tissue may lose its elasticity and become more brittle and prone to fractures as it ages. In the present study the age-dependent variation in the spatial distributions of microstructural and microelastic properties of the human femoral neck and shaft were evaluated by using acoustic microscopy. Although these properties may not be directly measured in vivo, there is a major interest to investigate their relationships with the linear elastic measurements obtained by diagnostic ultrasound at the most severe fracture sites, e.g, the femoral neck. However, before the validity of novel in vivo techniques can be established, it is essential to understand the age-dependent variation in tissue elastic properties and porosity at different skeletal sites. A total of 42 transverse cross-sectional bone samples were obtained from the femoral neck (Fn) and proximal femoral shaft (Ps) of 21 men (mean SD age 47.1 +/- 17.8, range 17-82 years). Samples were quantitatively imaged using a scanning acoustic microscope (SAM) equipped with a 50 MHz ultrasound transducer. Distributions of the elastic coefficient (c(33)) of cortical (Ct) and trabecular (Tr) tissues and microstructure of cortex (cortical thickness Ct.Th and porosity Ct.Po) were determined. Variations in c(33) were observed with respect to tissue type (c(33)Tr c(33)(Ct.Fn) = 35.3 GPa > c(33)(Tr.Ps) = 33.8 GPa>c(33)(Tr.Fn) = 31.9 GPa), and cadaver age (R-2= 0.28-0.46, p