强直性脊柱后凸后路VCR/VCD矫形有限元模拟系统研究

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.

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。

强直性脊柱后凸的截骨矫形研究在近年来取得了重要的突破，全脊柱截骨及去松质骨截骨是目前手术矫正强直性脊柱后凸的重要治疗方式。但治疗方式的选择上仍存在很多弊端，常由于对截骨节段、截骨方式的选择缺乏对其“个体化”应力及位移分布的理论依据，造成截骨后椎体不稳、硬膜皱缩、移位等严重并发症。我们通过建立强直性脊柱后凸三维有限元模型，分别拟在T10-L3不同节段行VCR/VCD模拟截骨，参照人体矢状位骨盆参数，计算截骨角度，研究模型中钉棒、椎体、截骨接触面在加载负荷下的应力分布及位移变化趋势。通过获得的生物力学数据，术前制定合理的截骨矫形方案。可有效防止术中截骨断端的前移、后移、侧移及旋转的发生，恢复人体脊柱的矢状位平衡，并降低脊髓损伤风险。本课题如期完成，取得了重大进展与实验成果，现发表文章10余篇。这不仅提高了我国强直性脊柱后凸截骨矫形的生物力学研究现状，更重要的是，将材料力学中有限元分析应用到医学中的强直性脊柱后凸截骨矫形等高难度手术中，并对截骨角度的计算进行改良与创新，为临床上脊柱畸形的截骨矫形治疗，提供个体化、安全的手术方案，具有广阔的应用前景。