摘要
背景:人体三维有限元仿真分析由于其自身的优越性,被广泛应用于人体生物力学研究,但对骨骼材料属性的赋值并未有确切的定论。目的:对踝关节进行力学有限元分析,探索出更符合临床实际情况的材料属性赋值方法。方法:对1例正常男性志愿者踝关节CT断层数据进行三维重建并进行曲面拟合,然后进行有限元网格划分,分别运用均一赋值法与灰度值赋值法2种方式对骨骼进行材料属性的赋予,模拟双腿站立、单足站立、正常步态、上楼梯、下楼梯等5种工况下踝关节的生物力学响应。结果与结论:①在5种工况下胫骨关节面、距骨体的应力峰值均一赋值组明显高于灰度值赋值组,2种赋值方法下腓骨关节面上的应力峰值相差不大;②均一赋值组在距骨颈处应力分布较为集中且分布区域面积较小,灰度值赋值组在距骨颈处应力分布较为均匀且分布区域面积覆盖整个距骨颈处;③均一赋值组形变量胫骨大于腓骨,灰度值赋值组腓骨大于胫骨;④均一赋值组胫骨与腓骨形变量的差值大于灰度值赋值组;⑤说明在对踝关节进行生物力学有限元分析中,灰度值赋值法更符合临床实际情况,具有更高的准确性且能在一定程度上解决由于个体差异性带来的建模误差。
BACKGROUND: Three-dimensional finite element simulation analysis of human body is widely used in human biomechanical research because of its own superiority, but the assignment of bone material properties has not been definitive.OBJECTIVE: To explore a more practical method of material attribute assignment by conducting finite element analysis of ankle joint biomechanics.METHODS: Three-dimensional reconstruction of the ankle joint CT data from a normal male volunteer was performed and underwent surface fitting. Then the finite element model was meshed, and the two methods of uniform assignment and gray value assignment were used to give the material properties of bones. The biomechanical response of the ankle joint in five working conditions: double leg standing, single foot standing, normal gait, upstairs and downstairs were simulated.RESULTS AND CONCLUSION:(1) In the five working conditions, the peak stress of body of talus in the uniformity group was obviously higher than that in the gray value assignment group. The stress value of the fibular joint surface was similar in the two methods.(2) In the uniform assignment group, the stress distribution was concentrated and the distribution area was narrow in the talar neck. The gray value assignment group had a uniform stress distribution at the talar neck and the distribution area covered the entire talar neck.(3) The tibial deformation was greater than fibula in the uniform assignment group, and the fibula deformation was greater than tibia in the gray value assignment group.(4) The uniform assignment group was larger than the gray value assignment group in the difference between the deformation of the tibia and the fibula.(5) In summary, in the finite element analysis of the ankle joint biomechanics, the gray value assignment method is more in line with the clinical actual situation, which has high accuracy and can solve the modeling error caused by the individual difference to some extent.
引文
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