STRESS AND DEFORMATION ANALYSIS OF DISTAL FIBULA BONE-PLATE CONSTRUCTS USING COMSOL MULTIPHYSICS

Abstract

Bone is a biologically active tissue that possesses the capability to repair on its own. However, to restore the anatomical alignment and functional integrity of unstable, displaced or load bearing fractures, surgical fixation is often required. Among ankle joint injuries, distal fibula fracture is the most common, which allows load to be distributed evenly and provide stability. The biomechanical performance of fixation devices, mainly bone plates, is strongly influenced by implant’s material properties, geometry, and stress- transfer characteristics. Poor material selection may cause excessive stress concentration, implant failure, delayed union or stress shielding, thereby undermining the overall bone repair outcomes. In this study, “FEM (Finite element method) based computational framework” was developed to analyze and investigate the stress distribution and deformation behavior of a fractured distal fibula. COMSOL Multiphysics 5.5 is used to model a bone-Plate fixation system to stabilize distal fibula fracture, using bone plate and screws. The fibula was modeled as cortical bone while different materials, including Ti– 6Al–4V alloy, stainless steel (SS316L) and polymethyl methacrylate (PMMA) were employed to design bone plate and screws to evaluate their biomechanical response. Physiologically relevant boundary conditions were simulated by fixing the proximal end of the fibula and applying a compressive load to the plate to mimic weight-bearing. The simulation outcomes identify the non-uniformity among stress and deformation along bone-plate construct, revealing maximum von Mises stress in distal region in parallel with total displacement. While areas of cortical bone away from fixation site possess significantly lower stress level. Metallic implants particularly Ti-6Al-4V revealed uniform stress deformation with reduced total deformation compared to PMMA. Hence indicating better load sharing characteristics and mechanical stability. The findings demonstrate the impact of implant stiffness on stress transfer and deformation behavior in distal fibula fixation. Overall, this FEM-based analysis adds meaningful biomechanical perspective into the performance of different bone plate materials for distal fibula fracture fixation. The results corroborate the metallic implants usage for improved mechanical stability and offer a computational basis for optimizing implant design, material selection, and clinical decision-making in orthopedic fracture management.