When bone is affected by osteoporosis, its strength diminishes and it becomes prone to fractures. Unfortunately, we still do not understand bone as a material or the full medical implications of osteoporosis. This project aims to comprehend the damage and failure mechanisms in bone as an organ, tissue, and material (hence on multiple length scales), to enable development of sophisticated methods for improving fracture risk assessment in osteoporosis.
The project is multidisciplinary and combines experimental imaging with the mechanical characterization of damage and fracture mechanisms at several different length scales (whole bone down to nanoscale), which serves as the ground for the development of computational models of bone damage and fracture mechanics. We hope this will lead to better tools to assess bone strength and fracture risk more accurately than what is possible today, thereby improving the diagnostics of osteoporosis.
Tomographic imaging can be used to visualize bone at a resolution down to some µm and by achieving in situ mechanical testing (inside the imaging set-up), we can follow and study how bone damages under a mechanical loading by image correlation. One goal is to better understand the bone-implant interface and to find how to promote bone formation around the implants. Another project aims to study the micro-crack propagation and local fracture formation of human trabecular bone under compression.
In the numerical part of this project, the aim is to create a multiscale model to study damage development in bone on several length scales. The extended finite element method (XFEM) is used to study the damage process and crack propagation to elucidate the effect of microstructure and local tissue properties on the strength and toughness of bone.
Funding: The project is funded by SFF, the Swedish Foundation for Strategic Research
Collaboration: Parts of the project are in collaboration with the Division of Solid Mechanics, and parts in collaboration with Department of Orthopaedics, Lund University.
Gustafsson, Khayyeri, Wallin, Isaksson, An interface damage model that captures crack propagation at the microscale in cortical bone using XFEM. Journal of the Mechanical Behavior of Biomedical Materials, 2018 (popular summary)
Gustafsson, Mathavan, Turunen, Engqvist, Khayyeri, Hall, Isaksson. Linking multiscale deformation to microstructure in cortical bone using in situ loading, digital image correlation and synchrotron X-ray scattering, Acta Biomaterialia, 2018 (popular summary)
Isaksson, Le Cann, Perdikouri, Turunen, Kaestner, Tägil, Hall, Tudisco. Neutron tomographic imaging of bone-implant interface: Comparison with X-ray tomography. Bone, 2017
Le Cann, Tudisco, Perdikouri, Belfrage, Kaestner, Hall, Tägil, Isaksson. Characterization of the bone-metal implant interface by Digital Volume Correlation of in-situ loading using neutron tomography. Journal of Mechanical Behavior of Biomedical Materials, 2017
Kaspersen, Turunen, Mathavan, Lages, Skov Pedersen, Olsson, Isaksson. Small-angle X-ray scattering demonstrates similar nanostructure in cortical bone from young adult animals of different species. Calcified Tissue International, 2016 (popular summary)
Turunen, Kaspersen, Olsson, Guizar-Sicairos, Bech, Schaff, Tägil, Jurvelin, Isaksson. Bone mineral crystal size and organization vary across mature rat bone cortex. Journal of Structural Biology, 2016.