Optimizing Locking Compression Plate Design via Segmental Stepped Thickness: A Biomechanical Simulation Approach

Locking compression plates (LCPs) are widely utilized in orthopaedic fracture fixation due to their superior mechanical stability and reliability. However, conventional LCPs fabricated from nonbiodegradable metals often cause stress shielding, long-term biocompatibility concerns, and necessitate secondary removal surgeries. Biodegradable alternatives such as magnesium (Mg) alloys have emerged as promising substitutes owing to their biocompatibility and controlled resorption, yet they frequently exhibit insufficient initial strength and rapid degradation in vivo. To overcome these limitations, a segmental stepped thickness locking compression plate (SSTLCP) is proposed. The SSTLCP incorporates discrete step-wise thickness variations across defined plate segments to achieve a tailored stiffness distribution, thereby minimizing stress shielding and promoting bone-plate load sharing during the healing process. Unlike conventional taper-based geometries, the segmented architecture is designed to sustain mechanical performance throughout the degradation period. Finite element method simulations were performed on both standard LCP and SSTLCP configurations under simulated degradation conditions. Mechanical behavior was assessed through four-point bending (4PBT) and axial compression tests (ACT) on bone-plate-screw assemblies. The SSTLCP exhibited 26% and 10.4% lower equivalent stresses under 4PBT and ACT, respectively, compared to the standard LCP. Moreover, the SSTLCP maintained structural integrity for up to two months under 4PBT and six months under ACT, assuming uniform thickness reduction during degradation. These findings, supported by high-fidelity surgical simulations and optimized meshing strategies, highlight the SSTLCP as a mechanically robust and biodegradable alternative to conventional metallic LCPs, offering enhanced durability and improved clinical performance for next-generation orthopaedic fixation systems.