胫骨pilon骨折受伤机制的有限元分析

目的 探讨胫骨pilon骨折发生过程中胫腓骨及远端关节面的应力分布规律。方法 选择1名健康男性志愿者建立胫腓骨及距骨的三维有限元模型，根据骨折发生特点设定工况，在中立位、背伸、跖屈、内翻、外翻5种不同工况下从距骨远端向近端进行静力加载，并将模型与地面进行碰撞。结果 在静载荷下,中立位应力主要分布于踝间线以前的内踝、胫骨踝穴顶前缘及外踝，背仲位应力主要分布于外踝及胫骨踝穴顶前部，跖屈位应力分布于胫骨踝穴顶后部，内翻位应力主要分布于外踝关节面及胫骨踝穴顶外侧部，外翻位应力主要分布于外踝关节面。在碰撞情况下，中立位应力分布与静载荷下一致，背伸立应力主要分布于踝间线以前，跖屈位应力主要分布于胫骨踝穴顶之踝间线后部及外踝关节面，内翻立应力主要分布于胫骨踝穴顶外部及外踝，外翻位应力主要分布于内踝、外踝及踝间线前部。腓骨关节面存静载荷作用下均处于高应力分布状态，在碰撞过程中亦最早接受应力分布。结论 腓骨是胫骨pilon骨折发生中最早受累且受累较重的部位。胫腓骨远端关节面在骨折发生中存在4个主要应力分布区，此4个应力区向近端延伸为内、外、前、后4个柱。

A finite element analysis of stress distribution in pilon fracture

Objective To study the stress distribution on the distal tibial and fibular articular surface in the occurrence of pilon fracture.MethodsFinite element models of tibia, fibula and talus were rebuilt based on the scanning data of a healthy male volunteer. Five working conditions, i.e., neutral position,dorsi-flexional position, plantar flexional position, inversion and eversion, were set according to the characteristics of the fracture. Static loads were applied from the distal to the proximal talus to simulate collisions of the models against the ground.ResultsUnder static loads, the stress at neutral position was focused chiefly on the medial malleolus, the top anterior border of tibial ankle mortise and lateral malleolus; the stress at dorsi -flexional position was focused chiefly on the lateral malleolus and the top anterior border of tibial ankle mortise; the stress at plantar flexional position was focused chiefly on the top posterior border of tibial ankle mortise; the inversion stress was focused chiefly on the lateral malleolus and the top lateral border of tibial ankle mortise; the eversion stress was focused chiefly on the lateral malleolus. In collisions, the stress at neutral position was focused chiefly on the top lateral border of tibial ankle mortise; the stress at dorsiflexional position was focused chiefly on the anterior part of the ankle; the stress at plantar flexional position was focused chiefly on the top posterior border of tibial ankle mortise and the lateral malleolus: the inversion stress was focused chiefly on the top lateral border of tibial ankle mortise and the lateral malleelus; the eversion stress was focused chiefly on the medial malleolus, the lateral malleolus and the anterior part of the ankle. When static loads were applied, the whole fibular articular surface was under high stress and accepted the force at first in the occurrence of collision.Conclusions In the occurrence of the pilon fracture, the fibula is an important part affected, and there are 4 major zones of stress distribution on the distal tibial and fibular articular surface. The stress distribution zones extend proximally to form the medial, lateral, anterior,and posterior columns.