一个新枕寰枢有限元模型的建立与生物力学分析

目的 建立一个新型枕寰枢复合体有限元模型并对其进行生物力学分析.方法 采集CT断层资料,应用Mimics软件完成枕寰枢的三维重建并获取点云数据,辅助以逆向工程完成骨性结构的曲面重构；采用Ture Grid软件建立包括关节软骨在内的全六面体有限元网格模型,建立模拟韧带的弹簧单元；在0.3 Nm和1.5 Nm外载荷下进行了前屈、后伸、侧屈和轴向旋转四种生理运动的生物力学分析及有效性验证.结果 该枕寰枢模型能对正常情况下生物力学特性如运动学、韧带应变、关节应力等进行预测.结论 枕寰枢有限元模型对枕颈交界区生物力学的改变及其稳定性的影响可以进行有效的、可重复的仿真分析,具有较高的实用性和临床参考价值.

A newly developed occipito atlantoaxial finite element model and its relative biomechanical analysis

Objective To establish a newly developed occipito atlantoaxial finite element model （FEM） and perform a biomechanical analysis of the occipital vertebral junction. Methods CT data of occipito atlantoaxial complex were obtained. Mimics software was used to establish the three dimensional reconstruction of occipito atlantoaxial complex and obtain the cloudy point data. Then reverse engineering approach was used to establish the surface reconstruction of bone structure and the geometric model. The whole hexahedral mesh FEM including articular cartilages was established using the True Grid software. The ligaments were modeled with nonlinear spring elements. The biomechanical analysis and validation was performed under physiologic loadings of 0.3 Nm and 1.5 Nm to simulate four motions of axial rotation, flexion, extension, and lateral bending, respectively. Results The occipito atlantoaxial FEM could be an effective method in predicting the kinematics, ligament strain and stress force of the joints in the occipito vertebral junction. Conclusion The occipito atlantoaxial FEM is an effective and repeatable method to study the changes of biomechanics and the influence of the stability of the occipital vertebral junction and is of higher practicability and clinical reference value.