摘要
背景:终板的组织形态改变可通过影响对椎间盘的营养传递最终导致椎间盘的退变。目的:观察终板凹陷程度变化对腰椎运动节段生物力学的影响。设计、时间及地点:有限元模型生物力学分析。于2005-01/2007-01在浙江大学医学院附属第二医院骨科生物力学实验室完成。材料:德国西门子SOMATOM SENSATION16螺旋CT机。ANSYS有限元分析软件(Inc.Pennsylvania,USA)。方法:在以往建立的腰椎L4～5运动节段三维非线性有限元模型基础上,采用CAD方法精确构建大、中、小3种不同终板凹陷角的有限元模型,有限元模型的椎间盘前凸角、小关节间隙等其余形态学参数及网格划分均保持一致。垂直压缩、屈曲、伸直、前后剪力5种载荷条件下,分别对3种有限元模型生物力学参数进行测试。主要观察指标:终板-椎间盘界面应变、椎间盘刚度、髓核内压、椎间盘膨出、纤维环纤维张应力、纤维环基质应力、腰椎后部结构应力以及关节突接触力。结果:负载条件下,终板凹陷角增加、终板凹陷程度减小可导致终板-椎间盘界面应变减小,椎间盘刚度及髓核内压增加,椎间盘膨出、纤维环纤维张应力、纤维环基质应力、腰椎后部结构应力以及关节突接触力减小。结论:终板凹陷程度的减小增强了椎间盘对椎体的保护作用;同时可通过影响终板的形变减少对椎间盘的营养传递。
BACKGROUND： Histomorphological change of endplate may affect the nutritional transmission of intervertebral disk, eventually leading to intervertebral disc degeneration.
OBJECTIVE： To observe the effects of endplate concavity variation on mechanical response of lumbar motion segment.
DESIGN, TIME AND SETTING： Repeated measurement design, biomechanical analysis of finite element models, performed at the Laboratory of Biomechanics, Department of Orthopedics, the Second Affiliated Hospital of Medical College of Zhejiang University between January 2005 and January 2007.
MATERIALS： SOMATOM SENSATION 16 spiral CT machine （Siemens, German） and ANSYS （Inc. Pennsylvania, USA）.
METHODS： A three-dimensional nonlinear geometrical and mechanical accurate finite element model of lumbar L4-5 segment was developed. Parametric studies were undertaken by studying endplate of three different concave angles, whereas disc angle, the gap of facet joint, finite element mesh density, and all other parameters were kept constant. Biomechanical parameters of three kinds of finite element models were tested under 5 different loading conditions, including vertical compression, flexion, extension, and anterior and posterior shearing loading.
MAIN OUTCOME MEASURES： Endplate-intervertebral disc interface strain, intervertebral disc stiffness, nucleus pulposus pressure, annular fiber,stress, radial disc bulge, stress in the annulus ground substance, stresses in posterior structure and facet contact force.
RESULTS： The decrease in the endplate concavity stimulated by an increasing endplate concave angle would result in decreased strains of endplate-intervertebral disc interface, increased disc stiffness and nucleus pulposus pressure, decreased annular fiber stress, radial disc bulge and stress in the annulus ground substance, and simultaneously produce decreased facet contact force and stresses in posterior structure.
CONCLUSION： The decrease of endplate concavity enhances the protective effects of the disc on
出处
《中国组织工程研究与临床康复》
CAS
CSCD
北大核心
2008年第44期8765-8770,共6页
Journal of Clinical Rehabilitative Tissue Engineering Research
基金
the Key Program of Science Research of Ministry of Health,No.WKJ 2005-Z-046~~
