Biomechanical Analysis of Two External Fixation Methods for Management of Type 4A2B2 Tibial Fractures Using Finite Element Analysis

Objective: To compare the biomechanics of two external fixation methods—the externally applied locking plate and the unilateral external fixator—for treating Type 4A2B2 tibial fractures using finite element analysis, and to provide a theoretical reference for clinical application. Methods: A three-dimensional model of a normal tibia was constructed based on computed tomography (CT) data of the left tibia from one healthy male volunteer using Mimics software (version 21.0; Materialise, Belgium), Geomagic Studio (version 2014; 3D Systems, USA), HyperMesh (version 14.0; Altair Engineering, USA), MSC Patran (version 2019; Hexagon Manufacturing Intelligence, USA), and MSC Nastran (version 2019; Hexagon Manufacturing Intelligence, USA). This model was then modified to create a Type 4A2B2 tibial fracture model. Based on the aforementioned fracture model, the finite element models of the locking plate and external fixator were meshed. Four different experimental conditions were simulated, namely, the four-point bending test, axial compression test, clockwise torsion test, and counterclockwise torsion test. A comparative analysis of the maximum stress and maximum displacement of the two fixation methods was conducted under these different conditions. Results: Under the four different testing conditions, it was found that the locking plate fixation exhibited a higher peak equivalent stress but a lower peak overall tibial displacement compared to the unilateral external fixator, at the respective maximum loads. Conclusion: The findings of this study suggest that externally applied locking plate fixation may offer superior biomechanical performance compared to unilateral external fixation in the treatment of Type 4A2B2 tibial fractures.