腰椎4、5间盘纤维环纤维层力学性能的实验研究

测试成人腰椎间盘纤维环纤维层的力学性能。用显微外科技术将纤维环逐层分离,每层纤维平均分成8个测点,每层每测点处按纤维走向切取5个试件,长度l=15~20mm,宽b=1~1.5mm,厚t=0.1~0.5mm。进行拉伸实验测得应力-应变曲线,并给出拟合曲线及方程,得出弹性模量、破坏应变、破坏应力、测点处的力学性能参数和方程。测试结果表明:各测点处,沿径向,由外向内弹性模量皆随层数的增加,不断变小;每层纤维弹性模量由前侧向后侧逐渐变小;破坏应力由外层向内层线性递减;破坏应变外部9层随层数增加略有提高,9层以后基本上为一常数(0.34±0.14)。可见,腰椎间盘纤维环纤维具有特殊的力学性能,与其功能相适应,与腰椎疾病的发生有密切的关系。

An Experimental Study on Mechanical Properties of Fiber Layers in Anulus Fibrosus of Lumbar Interverbral Disc 4,5

We tested the mechanical properties of fiber layers in adult anulus fibrosus of lumbar interverbral disc 4,5. Aulus fibrosus of lumbar interverbral disc was delaminated by using microsurgical technique. 8 testing points were taken in each layer according to the fibers going and 5 testing specimens were taken from each testing point. The length was 15-20mm, the width 1-2mm, and the thickness 0. 1-0. 5mm. By using tension test,the relationship curves of stress and strain were tested, the fitting curves and equations were obtained, and then the elastic modulus, damage strain and damage stress were obtained. Therefore we knew the parameters and equations of mechanical properties of each testing point. We got the result that the elastic modulus of each testing point, along the radius from outside to inside, decreased with the increase of layers. The damage stress decreased linearly from outside to inside. The damage strains of the outside 9 layers increased slightly with the increase of layers, and the others were almost constants, i. e. 0.34 +/- 0.14. We get the conclusion that analus fibrosus of intervertebral disc has special mechanical properties corresponding with its functions, which is in a close relationship with lumbar vertebral diseases.