Stokes I A
Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington 05405.
J Spinal Disord. 1988;1(3):189-93.
A noncontacting photogrammetric method was used to measure intervertebral disc bulge (deformation perpendicular to the disc surface) at an anterior site and a posterolateral site of 17 human lumbar discs. Specimens were tested in constructs consisting of two lumbar vertebrae and the intervening disc. The posterior elements were removed to give unobstructed visibility of the posterolateral aspects. Stereophotogrammetry was used to record the motion of target points attached to the disc and vertebral body surfaces. In axial loading, the bulging increased linearly with disc compression, which in turn had a nonlinear relationship with the applied load. Axial loads and offset compression loads of physiologic magnitude caused disc bulge that was generally less than 1 mm. Axial torsion of an otherwise unloaded specimen produced minimal change in disc bulge. The disc bulging measured in this study is generally less than that previously reported, especially for angular motions between the vertebrae. This is probably because the photogrammetric method used here is independent of motion of the vertebrae, which can corrupt mechanical, contacting methods of measurement.
采用一种非接触式摄影测量方法，对17个成人腰椎间盘的前侧和后外侧部位的椎间盘膨出（垂直于椎间盘表面的变形）进行测量。标本在由两个腰椎椎体及中间椎间盘组成的结构中进行测试。去除后部结构，以便能无阻碍地观察后外侧部位。利用立体摄影测量法记录附着于椎间盘和椎体表面的目标点的运动。在轴向加载时，膨出随椎间盘压缩呈线性增加，而椎间盘压缩又与施加的载荷呈非线性关系。生理大小的轴向载荷和偏心压缩载荷导致的椎间盘膨出通常小于1毫米。在其他情况下未加载的标本进行轴向扭转时，椎间盘膨出的变化极小。本研究中测量的椎间盘膨出通常小于先前报道的值，尤其是椎体之间的角向运动。这可能是因为这里使用的摄影测量方法独立于椎体的运动，而椎体运动可能会干扰机械接触式测量方法。
