新型一体化人工枢椎力学性能的有限元分析

Finite element analysis on the mechanical properties of a new integrated artificial axis

中文关键词:  一体化人工枢椎  枢椎肿瘤  有限元分析  生物力学

英文关键词:Integrated Artificial Axis  Axis tumor  Finite element analysis  Biomechanics

中文摘要:

  【摘要】 目的：通过有限元方法分析新型一体化人工枢椎的力学性能。方法：通过薄层CT扫描l名健康21岁男性志愿者颅颈椎（颅前窝至C7）获取其骨性结构信息。将信息导入医学三维重建软件，模拟手术完整切除C2并在此基础上建立新型一体化人工枢椎和异形钛网两套内固定系统三维有限元模型。通过Ansys 14.5有限元软件调整上颈椎的3D模型，使其与Panjabi尸体标本实验数据基本一致，以验证模型的有效性。然后在有限元软件Ansys 14．5中对模型枕骨髁部施加40N的压力模拟头颅重力，同时施加1.5N·m的力矩，使模型产生前屈、后伸、侧屈及旋转运动，分别测量两套内固定系统中假体的最大应力和最大位移，以及C3上终板的最大应力。结果：在后伸、前屈、侧屈及旋转4种工况下，一体化人工枢椎和异形钛网的最大应力值分别为199.79MPa、472.52MPa、239.96MPa、403.45MPa以及820.47MPa、848.98MPa、492.24MPa、804.12MPa；最大位移值分别为1.8734mm、1.8887mm、0.8121mm、2.6758mm以及2.4268mm、2.5195mm、0.9731mm、3.2075mm；C3椎体上终板的最大应力值分别4.5104MPa、5.8427MPa、4.0497MPa、12.7230Mpa以及4.8444Mpa、5.7976Mpa、6.4343Mpa、14.0820Mpa。结论：新型一体化人工枢椎假体在上颈椎前路重建手术方面可提供足够的固定强度和稳定性，与异形钛网相比，具有更好的稳定性和更少的应力集中等优势。

英文摘要:

  【Abstract】 Objectives: The mechanical properties of a novel Integrated Artificial Axis (IAA) were investigated using three-dimensional finite element analysis. Methods: To obtain the cervical Dicom format data (anterior cranial fossa to C7) of a healthy 21-year-old male volunteer by thin slice CT scan, and mimics software was imported for the three-dimensional reconstruction. Simulated complete C2 resection and three-dimensional finite element model of the integrated artificial cervical vertebra and the reconstruction with the modified T-shaped Harms cage were established. The 3D model of the upper cervical vertebra was adjusted by Ansys 14.5 finite element software to make it consistent with the experimental data of the Panjabi cadaver specimens, and the validity of the model was verified. Then, a compressive preload of 40N combined with a pure moment of 1.5N·m was applied to the superior of the occipital condyle to simulate flexion, extension, lateral bending and axial rotation respectively. The maximum stress and displacement of the prosthesis and the maximum stress on C3 endplate of the two sets of internal fixation system were measured. Results: Under four different situations, the maximum stress values of the integrated artificial axis system and the T-shaped Harms cage system were 199.79MPa, 472.52MPa, 239.96MPa, 403.45MPa and 820.47MPa, 848.98MPa, 492.24MPa, 804.12MPa respectively; the maximum displacement values of these two systems were 1.8734mm, 1.8887mm, 0.8121mm, 2.6758mm and 2.4268mm, 2.5195mm, 0.9731mm, 3.2075mm, respectively; the maximum stress values on C3 endplate of the two systems were respectively 4.5104MPa, 5.8427MPa, 4.0497MPa, 12.7230Mpa and 4.8444Mpa, 5.7976Mpa, 6.4343Mpa, 14.0820Mpa. Conclusions: The finite element mechanical analysis showed that the new integrated artificial axis prosthesis can provide sufficient fixation strength and stability after anterior cervical vertebrae reconstruction, and it has better stability and lower stress concentration comparing with the T-shaped Harms cage.