Orthopaedic Biomechanics Laboratory, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, UB19, Toronto, ON, M4N 3M5, Canada.
Ann Biomed Eng. 2010 Jan;38(1):41-56. doi: 10.1007/s10439-009-9821-z. Epub 2009 Oct 27.
Vertebrae provide essential biomechanical stability to the skeleton. In this work novel morphing techniques were used to parameterize three aspects of the geometry of a specimen-specific finite element (FE) model of a rat caudal vertebra (process size, neck size, and end-plate offset). Material properties and loading were also parameterized using standard techniques. These parameterizations were then integrated within an RSM framework and used to produce a family of FE models. The mechanical behavior of each model was characterized by predictions of stress and strain. A metamodel was fit to each of the responses to yield the relative influences of the factors and their interactions. The direction of loading, offset, and neck size had the largest influences on the levels of vertebral stress and strain. Material type was influential on the strains, but not the stress. Process size was substantially less influential. A strong interaction was identified between dorsal-ventral offset and dorsal-ventral off-axis loading. The demonstrated approach has several advantages for spinal biomechanical analysis by enabling the examination of the sensitivity of a specimen to multiple variations in shape, and of the interactions between shape, material properties, and loading.
椎体为骨骼提供了重要的生物力学稳定性。在这项工作中，使用了新的变形技术来参数化特定于标本的大鼠尾椎有限元（FE）模型的三个方面的几何形状（过程大小、颈大小和终板偏移）。还使用标准技术对材料属性和载荷进行了参数化。然后，这些参数化在 RSM 框架内进行集成，并用于生成一系列 FE 模型。通过预测应力和应变来描述每个模型的力学行为。为每个响应拟合了一个元模型，以得出因素及其相互作用的相对影响。加载方向、偏移量和颈大小对椎体的应力和应变水平有最大影响。材料类型对应变有影响，但对应力没有影响。过程大小的影响要小得多。在背腹向偏移和背腹向偏轴加载之间发现了很强的相互作用。通过使标本能够对形状的多种变化以及形状、材料属性和载荷之间的相互作用进行敏感性检查，该方法在脊柱生物力学分析方面具有多项优势。
