中国组织工程研究 ›› 2019, Vol. 23 ›› Issue (28): 4552-4557.doi: 10.3969/j.issn.2095-4344.1401

• 骨与关节生物力学 bone and joint biomechanics • 上一篇    下一篇

脊柱结核病灶清除术中单节段短椎弓根钉固定的三维有限元分析

李  翔,司建炜   

  1. 宁夏医科大学总医院脊柱骨科,宁夏回族自治区银川市  750000
  • 出版日期:2019-10-08 发布日期:2019-10-08
  • 通讯作者: 司建炜,硕士,主任医师,副教授,宁夏医科大学总医院脊柱骨科,宁夏回族自治区银川市 750000
  • 作者简介:李翔,男,1990年生,汉族,甘肃省人,2018宁夏医科大学毕业,硕士。
  • 基金资助:

    宁夏自然科学基金资助项目(NZ11198)

Three-dimensional finite element analysis of spine tuberculosis debridement treated by single-segment fixation with short pedicle screw

Li Xiang, Si Jianwei   

  1. Department of Spinal Orthopedics, General Hospital of Ningxia Medical University, Yinchuan 750000, Ningxia Hui Autonomous Region, China
  • Online:2019-10-08 Published:2019-10-08
  • Contact: Si Jianwei, Master, Chief physician, Associate professor, Department of Spinal Orthopedics, General Hospital of Ningxia Medical University, Yinchuan 750000, Ningxia Hui Autonomous Region, China
  • About author:Li Xiang, Master, Department of Spinal Orthopedics, General Hospital of Ningxia Medical University, Yinchuan 750000, Ningxia Hui Autonomous Region, China
  • Supported by:

    the Natural Science Foundation of Ningxia Hui Autonomous Region, No. NZ11198

摘要:

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文题释义:
有限元分析:是一种在工程力学领域常用的、高效能的数值计算方法。它将待研究对象通过计算机相关软件进行数值分割、离散,建立仿真环境中计算机数据模型,进而模拟研究内容,赋力学参数(如结构的平衡、压力、扭力及抗破坏性)等数值于模型,检测数据仿真模型的力学效能,目前广泛应运于军事、建筑、医学等领域。
有限元分析的优势:与传统的生物力学研究相比,有限元分析法具有省时快捷、费用低廉、应用面广、适应性强、无损耗等优势。
 
摘要
背景:脊柱结核手术治疗中使用单节段短椎弓根钉的方法已经在临床工作中运用,并取得满意的疗效,但这种固定方法的生物力学效能是否可靠,尚未得到理论研究证实。已有的研究虽证实短椎弓根钉能达到可靠的固定效果,但其研究方法局限于动物骨骼体外模拟实验,不能真实反映人体脊柱的生物力学特性。
目的:建立T12-L3脊柱结核病灶彻底清除术后单节段、短椎弓根钉固定的三维有限元模型,对模型进行力学分析,验证此种固定方式维持脊柱的稳定性。
方法:选择1例成年健康的男性志愿者,无脊柱疾病史,CT对脊柱行层厚1 mm的连续扫描,导出图像文件数据,以DICOM格式保存。运用Mimics 20.0,Geomagic Studio,Pro/E 5.0软件完成建立3种脊柱椎弓根钉固定模型,运用Abaqus软件进行有限元分析,在模型椎体上端上缘施加500 N的轴向垂直压力;在同一受力点上施加10 Nm大小的力矩,使椎体做前屈、后伸、左右侧弯及旋转运动,观察测量轴向位移及最大偏转角度。
结果与结论:对3种模型施加同样的荷载及边界条件,结果显示:①附加内固定的模型与正常椎体模型之间的结果无显著性差异;②在轴向位移方面,单节段短钉与正常椎体模型相差不到10%;③在最大偏转角度方面:后伸状态下两模型数据相差最大,单节段模型比正常模型大18%;④跨节段长钉固定模型无论在轴向位移还是在最大偏转角度上均低于正常椎体模型;⑤此2种内固定模型之间相比,单节段短钉模型轴向位移比跨节段长钉模型大16%,在最大偏转角度上后伸状态下两种固定模型的相差最大,单节段固定比跨节段多38%,其他状态下数据相差均较小,将2种固定模型行统计学检验,结果比较无显著性差异;⑥结果证实,单节段短椎弓根钉的固定方式能够达到可靠的生物力学效能,能维持脊柱结核病灶彻底清除术后脊柱的即刻稳定性。

ORCID: 0000-0003-3574-4248(李翔)

关键词: 脊柱结核, 彻底病灶清除术, 单节段固定, 跨节段固定, 短椎弓根钉, 长椎弓根钉, 有限元, 生物力学, 轴向最大位移, 最大偏转角度

Abstract:

BACKGROUND: Single-segment short pedicle screw has been applied in the surgical treatment of spinal tuberculosis in clinical practice and achieves satisfactory efficacy, but whether the biomechanical efficacy of this fixation method is reliable remains unclear. Although existing studies have proven that short pedicle screw can achieve reliable fixation effect, its research method is limited to animal bone in vitro simulation experiment, and cannot truly reflect the biomechanical characteristics of human spine. 
OBJECTIVE: To establish the three-dimensional finite element model of single-segment short pedicle screw fixation after the complete removal of T12-L 3 spinal tuberculosis foci, and to undergo the mechanical analysis, thereby verifying its spinal stability.
METHODS: One healthy adult male volunteer with no history of spinal disease was selected. CT scanning of the 1 mm thick intervertebral layer was performed continuously, and the image data were derived and saved in DICOM format. Mimics 20.0, Geomagic Studio, and Pro/E 5.0 software were used to establish three pedicle screw fixation models of the spine. Finite element analysis was performed using Abaqus software. A torque of 10 Nm was applied at the same stress point to make the vertebral body bend forward, extend backward, bend left and right side and rotate, and the axial displacement and the maximum deflection angle were measured.
RESULTS AND CONCLUSION: Applying the same load and boundary conditions to the three models, the results showed that: (1) There was no significant difference between the results of the model with additional internal fixation and the normal vertebral body model. (2) In terms of axial displacement, the single-segment short screw was less than 10% different from the normal vertebral body model. (3) In terms of the maximum deflection angle, the data of the two models were the most different in the post-extension state, and the single-segment model was 18% larger than the normal model. (4) The cross-segment screw fixation model was lower than the normal vertebral body model in both axial displacement and maximum deflection angle. (5) Compared between two kinds of internal fixation model, single-segment short nail model axial displacement was 16% larger than cross section long nail model. The difference between the two fixed models is the greatest at the maximum deflection angle and the backward extension state. The single-segment fixation was 38% more than cross section, and the difference of data in other states was small. The results of the two fixed line model statistical tests showed no significant difference. (6) These results indicate that the fixation method of single-segment short pedicle screw can achieve reliable biomechanical efficiency and maintain the immediate stability of the spine after the complete removal of the tuberculosis focus in the spine.

Key words: spine tuberculosis, complete removal of the focus, single-segment fixation, trans-segment fixation, short pedicle screw, long pedicle screw, finite element, biomechanics, maximal axial displacement, maximum deflection angle

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