Analysis on Biomechanical Properties of Anterior Ligament Reinforcement Combined with Screw Fixation for Inferior Tibiofibular Instability / 医用生物力学

ABSTRACT

Objective To establish the finite element (FE) model of the anterior tibiofibular ligament injury by ankle fracture fixation, so as to compare the stress and deformation of the finite element model by using anchor-reinforced repair combined with screw fixation. Methods CT images of the ankle joint from a normal young male volunteer was selected to establish the FE model of the anterior tibiofibular joint injury by ankle fracture fixation. The injury models were divided into experimental group and control group, which were fixed by anchors or screws, respectively. The maximum stress distributions and the maximum deformation of the two models under various load conditions were observed through the FE analysis and calculation. Results Under the vertical load, the deformation of the experimental group was 6.8% higher than that of the control group. The deformation increased by 22.6% under external rotation load, while the deformation decreased by 5.1% under internal rotation load. Under the same load, differences in the maximum peak stress on the model between the control group and the experimental group was not significant. Due to the anchor fixation, the maximum stress of the experimental group were borne by the screw that fixed the distal tibial fracture, while the maximum stress of the control group was borne by strong fixation of the steel plate and the inferior tibiofibular screw. The maximum stresses on the anchor were distributed on the screw, and the suture mainly played the role of fixing. Conclusions The lower tibiofibular screw and anchor fixation could effectively treat the tibiofibular instability left by ankle fracture fixation. The anchor fixation dispersed the stress on the steel plate, and it showed greater ankle joint deformation ability while fixing the lower tibiofibula, so as to avoid the risk of broken nails.