强直性脊柱炎所致严重的脊柱后凸在脊柱外科领域手术矫正是一大难题，它是一个大C形的后凸畸形。畸形常累及多个节段，矫正的手术方式、选择截骨的部位、宽度、节段数与矫正效果的关系及脊柱重建、规避手术风险的问题成为目前值得研究的难题。我们拟建立强直性脊柱后凸三维有限元模型；分别模拟在T9-L3不同节段行后路VCR/VCD 截骨矫形，研究后凸截骨后脊髓的松弛度、椎前血管的顺应性、脊柱重建固定钉加载负荷下的应力分析及确定固定的节段数，同时观察截骨间隙的闭合情况，有效防止截骨断端的前移、后移、侧移及旋转的发生和矢状位人体平衡参数的变化（后凸矫正前后三角函数得出的度数），近而最大程度的降低截骨后脊髓损伤的风险度，该课题通过与人类活体高度相似的有限元模型截骨为临床活体截骨提供参考数据，既获得最大的矫正效果，又最大程度降低手术风险，我们期待研究结果为临床科学、安全截骨矫形提供理论依据。

Surgical correction the severe kyphosis caused by ankylosing spondylitis is a major problem in the field of spinal surgery . It is a large C-shaped kyphosis，often involving multiple segments, the relationship between the operation mode of the correction, the select site、the width and the segments of the osteotomy with the correction effect and the reconstruction of the spine、the avoidance of surgical risk has become the subject worthy of study at current. We want to establish the dimensional finite element model of ankylosing spondylitis kyphosis, respectively simulated the posterior VCR / VCD osteotomy in different segments of T9-L3 , study the relaxation of spinal cord at the kyphosis osteotomy、compliance of anterior vertebral artery、the stress analysis of the reconstruction with the spinal fixation under load and the need fixed number of the segments. At the same time observe the closer of the osteotomy gap, effectively prevent the forward、backward、lateral and rotational occurrence of the osteotomy ends and the change of the sagittal balance of human body parameters ( The degree of trigonometric function before and after the kyphosis correction ) , after that to reduce the risk of the spinal cord injury after osteotomy by the greatest degree . From this subject we can provide reference data for clinical in vivo osteotomy that through the finite element model of osteotomy of the high similarity with human in vivo, both get the biggest correction effect and reduce operation risk. We expect the results will provide a theoretical basis for clinical science and safety osteotomy.