Finite element method-based simulation on bone fracture fixation configuration factors for biodegradable embossed locking compression plate

Abstract

As an evolution, biodegradable implants need to maximize mechanical performance thereby may lead to confusion in selection of the biodegradable material and implant design to the fracture site. This requires selecting a unique fixation configuration to fit within the fractured bone, factors of which can be bone-plate clearance, interfragmentary gap, alteration in screw fixation position and variation in the number of screws whose configuration optimization can re-maximize the mechanical performance of the biodegradable implant. Therefore, these factors have been optimized based on the induced minimum stress using the finite element method-based simulation for which biodegradable embossed locking plates (BELCP) via screws made of Mg-alloy have been fitted over two fragments of femur body (as hollow cylindrical cortical bone). An average human weight of 62 kg is applied to one segment of the femur for all different configurations of each factor, where another segment is assumed to be fixed. By this simulation, the most optimal fixation configuration was found at a minimum induced stress value of 41.96 MPa which is approximately 85%, 18%, 6% and 48% respectively less than all maximum stress induced configurations in each of the factor. This optimized configuration was at the minimum clearance between bone and plate with a 3 mm interfragmentary gap using 8 screws where the locking screw begins to apply from the center of the BELCP. Overall, BELCP may be a better biodegradable implant plate for bone fracture fixation with these optimized fixation configurations as the improved mechanical performance after experimental validation.