成人退变性脊柱侧凸后路三维矫形生物力学的有限元分析

摘要

目的 通过有限元方法模拟成人退变性脊柱侧凸后路三维矫形手术,比较不同置钉方案的矫形效果,探讨手术策略的选择.方法 通过CT图像建立1例退变性脊柱侧凸三维有限元模型,利用后路CD矫形模拟技术,分别设置不同的置钉方案,对比不同矫形操作中椎体成角及位移,比较术后矫形效果.结果 4种矫形方案的Cobb角以及腰椎前凸角无明显差别.融合至T10与融合至L1的矫形方案相比,顶椎区去旋转作用以及向中线纠正的能力更强.去旋转矫形过程中顶椎区的螺钉应力较高,尤其在长节段矫形方案.结论 对于Cobb角较小、脊柱平衡性以及柔韧性较好的成人退变性脊柱侧凸,短节段融合也能取得满意的效果.%Objective To simulate posterior 3D orthopaedic surgery based on a finite element model of adult degenerative scoliosis and compare the outcomes of different pedicle screw placement strategies so as to search for suitable surgical strategies. Methods A 3D finite element model of adult degenerative scoliosis was established based on the CT images of a diagnosed individual. According to the clinical reports of proximal and distal fusion strategy, several screw placement strategies were applied respectively with the aid of computer simulation program based on the finite element model. Vertebral displacement, rotation, angle changes and stress variation of pedicle screws were compared in the different stratigies. Results There was no significant difference in the correction of Cobb' s angle and lumbar lordosis between the four orthopedic strategies. Compared with fusion to L1, fusion to T10 was more powerful for correcting the scoliosis towards the center line, and had stronger ability of derotation. During derotation, the stress of screw in apex of the curve was much higher, especially in the long-fusion strategy. Conclusion For the adult degenerative scoliosis patients with small Cobb's angle, good spinal balance and good flexibility, short segment fusion can also achieve satisfactory results.