关子人体腰椎间盘生物力学的实验研究

SOME BIOMECHANICAL ASPECTS OF HUMAN LUNIBAR INTERVERTEBRAL DISC AN EXPERIMENTAL STUDY

本实验对人体腰椎间盘在静态非破坏性轴向压缩载荷、复合载荷(包括静态非破坏性轴向压缩合并右前弯曲加载和左前弯曲加载)和疲劳载荷下的力学性质作了初步研究。每一试件包括椎间盘及与其相邻的两椎体,利用万能材料试验机进行加载。复合加载是通过自行设计的一套卡具实现的,其上固定的十个传感器可测出椎间盘的轴向载荷、轴向位移与横向位移。考虑到椎间盘具有明显的粘弹性性质,故采用微机进行数据采集与处理。试验前后均进行X线检查。疲劳试验后的试件沿矢状面、额状面、横断面切片,脱去有机间质,于显微镜下观察了骨小梁的微观形态。根据所得结果讨论了椎间盘的力学性质与退变的关系,疲劳产生的骨小梁微观骨折与纤维环损伤。这些结果为椎间盘突出的X线所见与腰疼病因提供了某些力学理论依据。

ABSTRACT This paper deals with biomechanical responses of intervertebral disc to various load including axial, complex and fatigue load. 30 fresh disc specimens, each with its adjacent bodies, were tested on a universal testing machine fitted with a se't of exceptional fixtures, on which 10 transducers were installed so that the axial load,displacement and protrusion of the disc could be measured. In consideration of viscoelastisity of tlie disc, this measurement system was controlled by a microcomputer. Roentgenographs were made before and uftsr the static testing to examine macrostructura of the bodi.es. The specimens after fatigue testing were cut to many thin, slices parallel to the sagittal, frontal or transversal plane. These slices from which the mesenchyma was detached were obseryed under microscope. Relationship between mechanical characteristics of the disc' and its degeneration, microfracture of trabecula in vertebral bodies and injuries of annulus fibrosus created by fatigue testing were discussed. These results are deemed relevant to the clinical X-ray findings in protrusion and hernlation of intervertebral disc and low back pain,