Local microstrain variation in the compression of bionic bone with fracture fixation.

Abstract

Fracture fixation is a widely used surgical technique, and the internally fixed bone is inevitably subjected to loading during rehabilitation exercises. The precise characterization of global-local strain variation in fracture fixation remains underexplored. This study experimentally investigates global-local microstrain distribution in a bionic bone with fracture fixation under compression. The global response is directly derived from the universal testing machine. Strain gauges were employed to monitor surface microstrain on the bionic bone, while the digital image correlation (DIC) technique was used to characterize microstrain on the bone plate surface. An integrated system comprising a universal testing machine, strain gauges, and a DIC platform is employed to conduct global-local mechanical analyses of fracture fixation. Systematic regional microstrain measurements deliver unprecedented high-precision mechanical insights. Specifically, both the bionic bone and the plate exhibited localized microstrain variations. On the bone, microstrain magnitude and direction changed along the axial direction, with significantly higher strain on the side compared to the back. These findings highlight the heterogeneous strain distribution in fixed bones under loading, suggesting that rehabilitation strategies should account for localized mechanical responses. This study provides a foundation for the individualized customization of postoperative rehabilitation exercises. (196 words).