Biomechanical analysis of composite bone plates for tibial oblique fracture repair using finite element analysis

Tibial fractures are a common type of long bone injuries, requiring solid fixation for quicker bone healing and functional recovery. Metallic plates, although widely use, have been associated to stress shielding due to their enhanced stiffness, which can prevent callus formation and adversely affect the long-term outcomes. This study develops and assesses composite bone plates reinforced with unidirectional carbon fibres in different stacking sequences, comparing their biomechanical performance with titanium plates through finite element (FE) analysis. A 3D model of the tibia with a 1 mm oblique fracture gap was reconstructed from scanned bone data and simulated under physiological axial loading (700 N). Stress distribution within cortical and cancellous bone, plates and screws, as well as axial and shear displacements at the fracture site, were analyzed. Results demonstrated that composite plates (particularly configurations C4, C10 and C11) exhibited higher stress transfer to bone and greater controlled fracture gap movements compared with titanium, thereby minimizing stress shielding and promoting favorable conditions for callus formation. Axial and shear displacements with carbon/epoxy plates were 88% and 48% higher, respectively, than titanium plates, without compromising fixation stability. These findings suggest that carbon fibre-reinforced composites offer a promising alternative to metallic implants by balancing flexibility and stability, though further validation with nonlinear material models, cyclic loading and clinical trials is required.