Finite Element Analysis of Titanium Plates for Unilateral Condylar Neck Fracture Fixation: A Computational Study.

Introduction: Condylar neck fractures are challenging to treat owing to their intricate biomechanics, constrained accessibility, and narrow anatomical dimensions. This complexity hinders the precise placement of internal fixation devices and assurance of fracture stability. Despite various osteosynthesis devices, a lacuna persists regarding the effectiveness of these plates in stabilizing condylar neck fractures. This study compares the performance of five titanium osteosynthesis devices (single 4-hole Miniplate, Lambda, Trapezoidal, Rhomboidal, Alpha plates) in fixing unilateral condylar neck fractures using computational finite element analysis (FEA).

Method: Mandibular model, derived from a CT scan, underwent virtual condylar neck fracture simulation. Osteosynthesis plate models were adapted to the fractured segments. Implementing FEA, each model was evaluated under two loading scenarios: (i) reduced post-operative bite force of 135 N and (ii) clenching masticatory force of 500 N. Analysed parameters encompassed stress on screws across different plates, displacements along the fracture line, bone strains on the screw portion, and stress on plates, implant deformation, and rigidity.

Results: At 135N, all 5 plates offer an adequate fixation with a small risk of screw loosening for the rhomboidal and trapezoidal plates. For 500N, the lambda and alpha plates showed superior performance by evenly distributing strains within the bone, maintaining rigidity and reducing implant failure.

Conclusion: Lambda and Alpha plates demonstrated superior performance under increased loads. Conversely, Trapezoidal and Rhomboidal plates are not advisable for condylar neck fractures, particularly when anticipating larger functional loads.