Three-dimensional Analysis of Lumbar-spine Motion With Special Reference to the Etiology of Lumbar Instability

为了研究腰椎的物理运动或各种腰椎疾病的发病机制，在体内对腰椎运动进行三维测量是很重要的。作者开发了一套腰椎双平面x线摄影测量分析系统，这对这些受试者有很大的好处。该系统由参考系、带X-Y刻度的测量台和一台个人计算机组成。选取15名正常男性研究腰椎耦合运动。躯干最大扭曲时，整个腰椎轴向旋转角度约为7度。各椎间水平无显著差异。腰椎前凸角普遍减小，脊柱侧凸向扭曲方向凸出。为了评估退行性脊柱滑脱的三维不稳定性，我们使用了20例患者。退行性椎体滑脱的主要不稳定性不是屈伸不稳定，而是轴向旋转和前后移位不稳定。对20例峡部裂性滑脱患者进行了调查。屈伸角和轴向旋转角在溶解水平普遍增大，且后者远大于前者。

In order to investigate lumbar physical motion or the pathogenesis of various lumbar spinal diseases, it is important to measure the lumbar spinal motions three-dimensionally in vivo. The authors developed an analysis system of the lumbar spine using bi-plane X-ray photogrammetry, that was of great benefit to these subjects. The system is composed of a reference frame, a measuring table with X-Y magnescales, and a personal computer.Fifteen normal males were used to study lumbar coupling motions. The axial rotation angle, when the trunk was maximally twisted, was about 7 degrees in the whole lumbar spine. there was no significant difference at each inter-vertebral level. the lumbar lordotic angle was generally decreased, and the lumbar spine showed scoliotic curverture convex to the twisted direction.In order to evaluate three-dimensional instability in degenerative spondylo-listhesis, 20 patients were used. The major instability in degenerative spondylolisthesis was not the flexion-extension instability, but the axial rotational and the antero-posterior translational instabilities.20 patients of spondylolytic spondylolisthesis were investigated. Flexion-extension angle and axial rotation angle generally increased at lytic level, and the latter was much greater than the former.