畸形愈合的跟骨在不同步态位相应力分布的三维有限元研究

目的 对后关节面压缩的跟骨与距骨在步态过程中的应力变化进行生物力学分析。方法 在跟骨有限元模型上切割部分后关节面,模拟跟骨骨折后的后关节面压缩畸形。利用模拟畸形愈合的跟、距骨有限元模型模拟跟距骨在步态过程中三个位相(落地相、中立相、起步相)时的受力状况,进行有限元计算,并与正常状况进行分析。结果 获得了模拟畸形愈合的跟、距骨在三个位相时的应力分布和应力增高区,与正常状况时明显不同。结论 模拟畸形愈合的跟、距骨的应力分布变化对临床研究有重要意义,可对许多临床病理现象做出解释。

Stress Analysis of the Three-dimensional Finite Element Model of Malunion Calcaneus and Talus during Gait

Objective To analyze the stress distribution of calcaneus with posterior articular facet compressed after fracture and talus during gait. Methods Part of elements under the posterior articulation were removed from a normal finite element model of calcaneus and talus to simulate malformation of compression of the posterior facet after fracture of calcaneus. The model next was used to simulate for three subphases of the stance during the gait (heel-strike, midstance, push-off). Using a finite element solver to calculate. The results were compared with normal situation. Results The stress distribution within the bone in stuation of malformation was obtained and regions of elevated stresses for three subphases were located. The results were significantly different from that of normal situation. Conclusion The simulation of calcaneus and talus in malformation has important clinical meanings and can provide an insight into the factors contributing to many clinical pathogenic changes after fracture of calcaneus.