Finite element analysis of four different internal fixation strategies for tibial plateau fractures

To compare the biomechanical behaviour of four internal fixation strategies for AO/OTA type 41-C2 tibial plateau fractures using finite element analysis (FEA) under standardised loading conditions and to provide comparative biomechanical evidence for further evaluation of these fixation constructs. Computed tomography (CT) data from a healthy 26-year-old male were used to reconstruct a three-dimensional (3D) model of the tibia. An AO/OTA type 41-C2 tibial plateau fracture model was created and four internal fixation strategies were simulated: Group A, lateral plate fixation; Group B, intramedullary nail fixation; Group C, dual-plate fixation (lateral plate combined with medial plate); and Group D, plate-nail fixation (lateral plate combined with intramedullary nail). Finite element models were constructed in Abaqus, and two loading conditions were applied: axial compression (700 N) and varus loading (200 N). Maximum displacement, apparent construct stiffness, and von Mises stress distribution were used to compare resistance to deformation and implant stress among the four constructs. Under axial loading, the maximum displacement occurred at the posteromedial tibial plateau in all groups, with values of 1.421 mm (Group A), 0.315 mm (Group B), 0.816 mm (Group C), and 0.308 mm (Group D). The corresponding peak von Mises stresses in the fixation systems were 630.7 MPa, 134.0 MPa, 380.1 MPa, and 123.3 MPa, respectively. Under varus loading, the maximum displacement occurred at the lateral plateau in Groups A and B (2.598 and 0.622 mm, respectively) and at the medial plateau in Groups C and D (1.136 and 0.335 mm, respectively). The corresponding peak von Mises stresses were 755.1 MPa, 88.0 MPa, 317.3 MPa, and 72.8 MPa. Among the four simulated constructs, Group D showed the lowest maximum displacement and peak implant stress under both loading conditions, whereas Group A showed the highest values. Under the specific loading and boundary conditions simulated in this finite element study, intramedullary nail fixation and plate-nail fixation showed lower displacement and peak implant stress than lateral plate and dual-plate fixation. Plate-nail fixation showed the lowest displacement and peak implant stress among the four constructs. Not applicable.