横连接在经伤椎置钉治疗脊柱爆裂骨折应用的有限元分析

Finite Element Analysis of the Application of Transverse Connection in the Treatment of Spinal Burst Fractures with Screw Placement through the Injured Vertebra

摘要: 在胸腰段脊柱爆裂骨折中，分析伤椎置钉方式和横连对脊柱内固定系统的作用。本文应用医学有限元的方法，通过影像学数据得出T11-L3脊柱模型，应用“V”型截骨的方式模拟脊柱爆裂骨折术后复位的状态，给予跨伤椎固定、经伤椎椎弓根固定和经伤椎椎体固定的3种置钉方法，结合是否放置横连，组合成6种内固定方式，结合术后去除内固定的2种椎体模型，比较置钉和横连的作用。测量不同内固定模型在前屈、后伸、侧屈、扭转和纯重力的活动状态下的活动度和等效应力。结果：随着伤椎置钉长度的增大，椎体整体活动度下降，椎弓根钉和纵棒的最大应力减低。横连在扭转的活动状态时起到一定作用。结论：经伤椎椎体置钉是治疗脊柱爆裂骨折内固定的良好办法，横连在脊柱扭转时起到一定作用，经伤椎椎体6钉内固定可以起到良好的固定效果，无需放置横连。

Abstract: In thoracolumbar spinal burst fractures, the effects of screw placement and transverse connection on the spinal internal fixation system were analyzed. In this paper, the medical finite element method is used to obtain the T11-L3 spinal model through imaging data, and the “V”-shaped oste-otomy is used to simulate the postoperative reduction state of the spinal burst fracture. Three kinds of screw placement methods of root fixation, including Cross-injured vertebral fixation, trans-injured vertebral pedicle fixation and trans-injured vertebral body fixation, combined with whether to place a transverse connection, combined into 6 internal fixation methods, combined with two kinds of vertebral body models that removed the internal fixation after operation, com-pared the methods of screw placement and transverse connection effect. The range of motion and von-Mises stress of different internal fixation models is measured in flexion, extension, lateral bending, rotation and pure gravity. Results: With the increase of the screw length in the injured vertebra, the overall range of motion of the vertebral body decreased, and the maximum stress of the pedicle screw and the longitudinal rod decreased. The transverse connection plays a role in the rotated active state. Conclusion: Insertion of screws through the injured vertebrae is a good method for internal fixation of spinal burst fractures. The transverse connection plays a certain role in spinal rotation. Internal fixation with 6 screws through the injured vertebrae can achieve a good fixation effect without placing transverse connection.