Comparative Orthopaedic Research Unit, University of Bristol, Bristol, UK.
Eur Spine J. 1993 Mar;1(4):214-21. doi: 10.1007/BF00298362.
The purpose of this investigation was to test the hypothesis that damage to a lumbar vertebral body can lead to abnormal stress concentrations in the adjacent intervertebral discs. Twenty-three cadaveric lumbar "motion segments", from persons who had died aged between 19 and 87 years, were subjected to substantial compressive loading while in the neutral, lordotic and flexed "postures". During the loading period, a miniature pressure transducer was pulled through the disc along its mid-sagittal diameter and graphs of horizontal and vertical compressive stress against distance were obtained. Measurements were repeated after each motion segment had been compressed up to the point of mechanical failure: at this point the vertebral bodies suffered minor damage to the trabecular arcades, and sometimes to the end-plate, but the structure remained essentially intact and motion segment height was reduced by only 1%-2%. After damage, the stress in the nucleus and anterior annulus fell by about 30%, and high stress peaks appeared in the inner posterior annulus. These changes were more pronounced in lordotic posture and less pronounced in flexion. The youngest discs showed the smallest changes. It is concluded that minor compressive damage to the vertebral body can lead to high stress concentrations in the posterior annulus. Since the vertebral body is the "weak link" of the lumbar spine, this may be a frequent precipitating cause of isolated disc failure in living people.
本研究旨在验证下述假说，即腰椎体损伤可导致相邻椎间盘内异常的应力集中。23 个来自 19 至 87 岁死亡者的腰椎“运动节段”，在中立位、前凸位和前屈位时承受较大的压缩载荷。在加载过程中，微型压力传感器沿椎间盘的中矢状径被拉入，获得水平和垂直压缩应力随距离的变化图。每个运动节段压缩至机械失效点后重复测量：此时，椎体的骨小梁拱和（或）终板出现轻微损伤，但结构基本完整，运动节段高度仅降低 1%-2%。损伤后，核和前纤维环内的应力下降约 30%，内层后纤维环内出现高应力峰值。前凸位时变化更明显，前屈位时变化较小。年轻的椎间盘变化最小。结论是，椎体的轻微压缩性损伤可导致后纤维环内的高应力集中。由于椎体是腰椎的“薄弱环节”，这可能是活体中孤立性椎间盘破裂的常见诱发原因。
