Department of Orthopaedics, Peking University Third Hospital, China.
Bone. 2013 Aug;55(2):288-91. doi: 10.1016/j.bone.2013.04.006. Epub 2013 Apr 16.
The collagen phase plays an important role in mechanical behaviors of cortical bone. However, aging effects on the mechanical behavior of the collagen phase is still poorly understood. In this study, micro-tensile tests were performed on demineralized human cortical bone samples from young, middle-aged, and elderly donors and aging effects on the mechanical properties of the collagen phase in different orientations (i.e. longitudinal and transverse directions of bone) were examined. The results of this study indicated that the elastic modulus and ultimate strength of the demineralized bone specimens decreased with aging in both the longitudinal and transverse orientations. However, the failure strain exhibited no significant changes in both orientations regardless of aging. These results suggest that the stiffness and strength of the collagen phase in bone are deteriorated with aging in both longitudinal and transverse directions. However, the aging effect is not reflected in the failure strain of the collagen phase in both longitudinal and transverse orientations, implying that the maximum sustainable deformation of the collagen phase is independent of aging and orientation.
胶原相在皮质骨的力学行为中起着重要作用。然而，胶原相的老化效应仍知之甚少。在这项研究中，对来自年轻、中年和老年供体的脱矿化人皮质骨样本进行了微拉伸测试，并研究了老化对不同方向（即骨的纵向和横向）胶原相机械性能的影响。研究结果表明，在纵向和横向两个方向上，脱矿骨标本的弹性模量和极限强度随老化而降低。然而，无论老化如何，失效应变在两个方向上均无明显变化。这些结果表明，胶原相在骨中的刚度和强度随老化在纵向和横向两个方向上均会恶化。然而，老化效应在纵向和横向两个方向的胶原相失效应变中并未体现，这意味着胶原相的最大可持续变形与老化和方向无关。
