退变及加载方式对于高加载速率下椎间盘力学行为的影响

Effects of degeneration and loading mode on the mechanical behavior of intervertebral discs at high loading rates

腰椎间盘退变导致了整个腰椎间盘粘弹性特性的变化,但是对于腰椎间盘退变的确切机制目前仍知之甚少,特别是在加载方式和高加载速率方面。利用胰蛋白酶溶液制备退变牛腰椎间盘模型,应用数字图像相关技术对退变椎间盘进行轴向压缩实验,研究加载方式对于高加载速率下腰椎间盘内部位移分布及弹性模量的综合影响。结果表明:无论退变前后,高加载速率下腰椎间盘的弹性模量均显著高于准静态加载时。退变对于弹性模量的影响及高加载速率下腰椎间盘内部位移分布的影响均与加载方式有关。组织切片染色结果表明,椎间盘的髓核和纤维环组织在注射胰蛋白酶后产生了不同程度的结构破损。

Degeneration of the lumbar disc leads to changes in the viscoelastic properties of the entire lumbar disc,but the exact mechanism of lumbar disc degeneration is still poorly understood in the existing studies,especially in terms of loading mode and high loading rate.Preparation of a degenerated bovine lumbar intervertebral disc model using trypsin solution,application of digital image correlation techniques for axial experiments experiments on degenerated intervertebral discs are used in study of the combined effects of loading methods on the internal displacement distribution and elastic modulus of the lumbar disc at high loading rates.The results showed that the modulus of elasticity of the lumbar disc was significantly higher at high loading rates than at quasi-static loading,both before and after degeneration.The effect of degeneration on the modulus of elasticity and the effect of degeneration on the internal displacement distribution of the lumbar disc at high loading rates are both related to the loading method.Staining of tissue sections showed that the nucleus pulpous and fibrous ring tissue of the intervertebral disc produced varying degrees of structural breakage following trypsin injection.