改道重新置入椎弓根螺钉的有限元分析与生物力学验证  

Finite element analysis and biomechanical validation of revision pedicle screw placement

作　　者：马双双 高德东 单中书[2] 徐温旭 卢陟睿 Ma Shuangshuang;Gao Dedong;Shan Zhongshu;Xu Wenxu;Lu Zhirui(College of Mechanical Engineering,Qinghai University,Xining 810016,Qinghai Province,China;Department of Orthopedics,Qinghai Provincial People’s Hospital,Xining 810016,Qinghai Province,China;College of Computer Technology and Application,Qinghai University,Xining 810016,Qinghai Province,China)

机构地区：[1]青海大学机械工程学院,青海省西宁市810016 [2]青海省人民医院骨科,青海省西宁市810016 [3]青海大学计算机技术与应用学院,青海省西宁市810016

出　　处：《中国组织工程研究》2025年第33期7087-7095,共9页Chinese Journal of Tissue Engineering Research

基　　金：青海省科技计划项目(2020-ZJ-T08),项目名称:基于3D打印的数字化骨科精准医疗创新服务平台建设,项目负责人:单中书;青海省中央引导地方科技发展资金项目(2024ZY032),项目名称:数字智能医学技术辅助脊柱精准微创诊疗的应用示范与推广,项目负责人:单中书。

摘　　要：背景:目前,椎弓根螺钉固定技术被公认为腰椎后路融合的金标准,然而,该技术也存在一些负面并发症,例如置钉方向不理想、螺钉松动、断裂等。针对这一问题,有必要对螺钉重新置钉的力学特性进行深入研究,优化置钉方案提高手术的成功率和安全性。目的:通过结合有限元分析和生物力学实验验证,对传统轨迹椎弓根螺钉在多次拔出过程中的力学性能进行对比分析,以揭示螺钉在多次拔出过程中拔出强度的变化规律,为临床提供关于椎弓根螺钉重新置钉的安全性和有效性方面的科学依据。方法:基于CT扫描数据三维重建L4腰椎模型,利用3D打印技术打印生物实验样本,并按照置钉方案进行拔出实验。根据CT数据和标准椎弓根螺钉参数,建立L4腰椎有限元模型和椎弓根螺钉模型(直径为6.0 mm,长度为45 mm),根据置钉角度和次数将模型分为5种工况,建立有限元模型来模拟轴向拔出力实验,通过观察椎体的应力分布以及螺钉的轴向最大拔出强度,将3D打印力学实验结果与仿真结果进行对比分析。结果与结论:①设计并搭建了一套椎弓根螺钉拔出实验装置;②3D打印力学实验中对比正常置钉和一次不理想置钉工况下的4组模型,正常置钉组模型展示了最大抗拔出力,为(1422.63±23.80)N,且随着置钉偏移角度的增大,各组模型的最大抗拔出力逐渐减小;③对比一次不理想置钉和修正置钉工况,当不理想置钉偏移角度大于3号模型的角度时,重新以正常角度置钉有助于提升螺钉的抗拔出力;④对比二次不理想置钉和再次修正置钉工况,重新以正常角度置钉工况降低了螺钉的抗拔出力,不更换螺钉情况下不建议进行第3次置钉;⑤3D打印力学实验得出的拔出强度与有限元模拟得出的拔出强度具有较高的相关性,相关系数为0.98,两种方法的结果无显著差异(P>0.05)。BACKGROUND:Currently,pedicle screw fixation technology is recognized as the gold standard for lumbar posterior fusion surgery.However,this technique is associated with several complications such as suboptimal screw placement,loosening,and fracture.Addressing these issues,it requires a thorough investigation into the mechanical properties of screw reinsertion to optimize surgical procedures and enhance success rates and safety.OBJECTIVE:By combining finite element analysis with biomechanical experiments,this study aims to compare and analyze the mechanical performance of traditional trajectory pedicle screws during multiple extraction processes.The goal is to reveal patterns in screw extraction strength over repeated withdrawals,providing scientific insights into the safety and effectiveness of pedicle screw reinsertion for clinicians.METHODS:Based on CT scan data,a three-dimensional reconstruction of the L4 vertebra model was performed.Three-dimensional printing technology was used to create biological experimental samples.A pull-out experiment was conducted according to a screw placement plan.Utilizing CT data and standard pedicle screw parameters,a finite element model of the L4 vertebra and a pedicle screw model(diameter 6.0 mm,length 45 mm)were established.The model was divided into five operating conditions based on screw placement angle and cycles.A finite element model was developed to simulate axial pull-out testing,analyzing stress distribution in the vertebral body and maximum axial pull-out strength of the screw.Mechanics experimental results of three-dimensional printing were compared and analyzed against simulation outcomes.RESULTS AND CONCLUSION:(1)A dedicated experimental setup for pedicle screw extraction from single vertebrae was designed and constructed.(2)In the three-dimensional printing experiment,our groups of models were compared between correctly placed screws and once improperly placed screws.The correctly placed screws group exhibited a maximum pull-out force of(1422.63±23.80)N.Furtherm

关 键 词：椎弓根螺钉 腰椎 脊柱固定 应力分析 拔出强度 改道置钉 有限元分析 生物力学 

分 类 号：R459.9[医药卫生—治疗学] R318[医药卫生—临床医学] R681.5