Three-Dimensional Finite Element Analysis Of Ankle Arthrodesis

Background: Ankle arthrodesis is the gold standard and most commonly used method for the treatment of post-traumatic ankle arthritis. Aims: This study is to investigate the biomechanical safety and stability of four ankle fusion models through three-dimensional finite element analysis. Methods: Four ankle fusion models were established, including anterior plate ankle fusion model, lateral plate ankle fusion model, anterior plate plus posterolateral screw ankle fusion model and lateral plate plus posterolateral screw ankle fusion model. The four movement modes of the ankle internal rotation, external rotation, dorsiflexion and neutral mode were respectively simulated. The maximum displacement of the fusion surface and the stress of four movement modes were measured and analyzed. Results: The anterior plate plus posterolateral screw ankle fusion model had significantly decreased maximum surface displacement at all four movement modes than the anterior plate ankle fusion model (P<0.05). The maximum surface displacement of the lateral plate plus posterolateral screw plate ankle fusion model was significantly reduced at all four movement modes than that of the lateral plate ankle fusion model (P<0.05). Similarly, the stress peak of bone, plate and screw in the anterior/lateral plate plus posterolateral screw ankle fusion model was significantly reduced than that in the anterior/lateral plate ankle fusion model at the internal rotation state, the external rotation state and the dorsiflexion state, respectively (P<0.05). There was no significant difference at the neural state. Conclusion: The anterior/lateral plate plus posterolateral screw ankle fusion models have better fusion safety and higher fusion stability.