上颈椎前路钩状钛板内固定系统的三维有限元分析  

Finite element analysis of anterior upper cervical hook-plate internal fixation system

作　　者：蔡斌[1] 王文军[1] 晏怡果[1] 姚女兆[1] 宁栩 王明[1] CAI Bin;WANG Wen-jun;YAN Yi-guo;YAO Nv-zhao;NING Xu;WANG Ming(Department of Spine Surgery,First Affiliated Hospital,South China University,Hengyang 421001,China)

机构地区：[1]南华大学附属第一医院脊柱外科,421001

出　　处：《中国矫形外科杂志》2020年第8期728-733,共6页Orthopedic Journal of China

基　　金：湖南省衡阳市科技局课题项目(编号:2017KJ313);湖南省卫计委重大专项项目(椎间盘退行性疾病微创精准性治疗的基础和临床应用研究)。

摘　　要：[目的]运用有限元方法评估钩板内固定和椎弓根螺钉内固定的活动度和应力分布特点,并评价钩状钛板的生物力学性能和应力分布情况。[方法]运用有限元软件建立枢椎椎体缺失模型,并将钩板内固定和椎弓根钉棒内固定加载到缺损模型上,进行计算和分析,得到各个有限元模型的活动度(ROM)和应力分布云图。[结果]缺损模型和正常模型比较,在前屈工况下存在明显不稳。两种内固定模型的稳定性均明显强于正常模型及缺损模型。钩板模型在侧屈工况下稳定性略强于钉棒模型,而在其他工况下,其稳定性要略差于钉棒模型。钩板内固定在前屈下最大应力值略小于钉棒内固定,而在其他工况下,均明显大于钉棒内固定,应力主要集中在钩板连接处。钉棒内固定应力分布较为平均,最大应力区域主要位于C1侧块螺钉尾部。[结论]钩板模型的稳定性明显强于正常模型和缺损模型,但略差于钉棒模型,可以达到临床稳定性要求。钩板连接部应力过高,此处易产生断裂。[Objective] To evaluate biomechanical stability, security and stress distribution of upper cervical hook-plate fixation versus pedicle screw fixation by finite element method. [Methods] Based on a finite element model of cervical spine created with software by using image data of a health young man, the axis defect, and then the hook-plate fixation and pedicle screw fixation were mimicked to make models correspondingly. Under loading on the models, the ROM of each model and the stress cloud of the internal fixation implants were calculated and analyzed. [Result] Compared with the normal model, the defect model was unstable only in forward flexion. The stability of the two internal fixation models was significantly stronger than that of the normal model and the defect model. The stability of hookplate model was slightly stronger than that of pedicle screw model only under lateral bending condition, while it became inferior to the pedicle screw model under other conditions.In terms of stress, the maximum stress of hook-plate fixation was slightly less than that of pedicle screw fixation under for-ward flexion, but it was obviously greater than the latter under other conditions. The stress of hook-plate fixation mainly concentrated on the hook-plate connection, while the stress of pedicle screw fixation was relatively average and the maximum stress area was mainly located at the tail of C1 screw. [Conclusion] The hook-plate fixation is obviously more stable than normal upper cervical spine and axis defect spine, regardless to slightly inferior to pedicle screw fixation, and does meet the requirements of clinical setting enough. However, hook-plate connection has stress concentration, where is at risk of fracture.

关 键 词：上颈椎 枢椎椎体病变 有限元 生物力学 内固定 

分 类 号：R687[医药卫生—骨科学]