三维有限元分析钢板踝关节融合后的力学稳定性

Mechanical stability after plating ankle arthrodesis based on three-dimensional finite element analysis

背景:目前钢板踝关节融合方式主要包括前侧钢板及外侧钢板踝关节融合,但针对上述2种固定方式对比的生物力学研究未见报道。目的:通过三维有限元技术分别建立前侧及外侧钢板踝关节融合三维有限元模型,模拟人体步态,分析其生物力学稳定性及安全性。方法:基于正常人体踝关节CT图像重建踝关节几何形态,应用限元分析软件Abaqus 2016建立前侧钢板及外侧钢板踝关节融合模型,分别给予模型施加内旋、外旋、背屈、中立4种应力,分析其生物力学变化。结果与结论:(1)三维有限元生物力学分析对比2种踝关节融合模型在不同应力下的最大位移及应力分布情况,在固定稳定性上两者并无明显差异;(2)外侧钢板融合模型在对抗内旋及背屈应力时稍好于前侧钢板,外旋应力时反之,峰值都集中于钢板螺钉结合处;(3)前侧钢板模型在对抗内旋应力时钢板、螺钉及骨质应力峰值最大,存在断钉及断板的可能;(4)外侧钢板在对抗外旋应力时出现最大应力峰值。

BACKGROUND:Plating ankle arthrodesis includes anterior and lateral plating methods,but there is some lack of knowledge about their differences in biomechanics.OBJECTIVE:To establish the three-dimensional models of anterior and lateral plating ankle arthrodesis through three-dimensional finite element technique,simulate human gait,and to analyze its biomechanical stability and safety.METHODS:The geometrical morphology of ankle joint was reconstructed based on the normal human ankle CT data.The models of anterior and lateral plating ankle arthrodesis were established using finite element analysis software Abaqus 2016,and the biomechanical changes after exerting stress at the positions of intorsion,extorsion,dorsiflexion,and neutral were analyzed.RESULTS AND CONCLUSION:(1)The maximal displacement and stress distribution under different stress were compared between two models by three-dimensional element analysis,and there was no significant difference in the stability between two models.(2)The abilities of resistance to intorsion and dorsiflexion stresses of the lateral plating model were slightly better than those of the anterior plating model,but the resistance to extorsion stress of the lateral plating model was lower than that of the anterior plating model;the stress peak both concentrated on the plate-screw connections.(3)The plate,screw and bone mass of the anterior plating model showed the maximum stress peak under intorsion stress,and broken plates and nails usually occur.(4)The lateral plating presented with peak stress under extorsion stress.