A New Microarchitecture-Based Parameter to Predict the Micromechanical Properties of Bone Allografts

Scaffolds are an essential component of bone tissue engineering. They provide support and create a physiological environment for cells to proliferate and differentiate. Bone allografts extracted from human donors are promising scaffolds due to their mechanical and structural characteristics. Bone microarchitecture is well known to be an important determinant of macroscopic mechanical properties, but its role at the microscopic, i.e., the trabeculae level is still poorly understood. The present study investigated linear correlations between microarchitectural parameters obtained from X-ray computed tomography (micro-CT) images of bone allografts, such as bone volume fraction (BV/TV), degree of anisotropy (DA), or ellipsoid factor (EF), and micromechanical parameters derived from micro-finite element calculations, such as mean axial strain (epsilon(z)) and strain energy density (W-e). DAEF, a new parameter based on a linear combination of the two microarchitectural parameters DA and EF, showed a strong linear correlation with the bone mechanical characteristics at the microscopic scale. Our results concluded that the spatial distribution and the plate-and-rod structure of trabecular bone are the main determinants of the mechanical properties of bone at the microscopic level. The DAEF parameter could, therefore, be used as a tool to predict the level of mechanical stimulation at the local scale, a key parameter to better understand and optimize the mechanism of osteogenesis in bone tissue engineering.

Automated summary

Scaffolds play a crucial role in bone tissue engineering by providing support and creating a suitable environment for cell growth and differentiation. Bone allografts extracted from human donors are considered promising scaffolds due to their mechanical and structural characteristics. This study used X-ray computed tomography (micro-CT) images to investigate the correlation between microarchitectural parameters and micromechanical properties of bone allografts. The results showed that the distribution and structure of trabecular bone at the microscopic level are the main factors determining its mechanical properties. A new parameter called DAEF was found to have a strong linear correlation with the bone's mechanical characteristics.