Full-Field Strain Analysis of Bone-Biomaterial Systems Produced by the Implantation of Osteoregenerative Biomaterials in an Ovine Model

Osteoregenerative biomaterials for the treatment of bone defects are under much development, with the aim of favoring osteointegration up to complete bone regeneration. A detailed investigation of bone-biomaterial integration is vital to understand and predict the ability of such materials to promote bone formation, preventing further bone damage and supporting load-bearing regions. This study aims to characterize the ex vivo micromechanics and microdamage evolution of bone-biomaterial systems at the tissue level, combining high-resolution synchrotron microcomputed tomography, in situ mechanics and digital volume correlation. Results showed that the main microfailure events were localized close to or within the newly formed bone tissue, in proximity to the bone-biomaterial interface. The apparent nominal compressive load applied to the composite structures resulted in a complex loading scenario, mainly due to the higher heterogeneity but also to the different biomaterial degradation mechanisms. The full-field strain distribution allowed characterization of microdamage initiation and progression. The findings reported in this study provide a deeper insight into bone-biomaterial integration and micromechanics in relation to the osteoregeneration achieved in vivo for a variety of biomaterials. This could ultimately be used to improve bone tissue regeneration strategies.