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

Abstract

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 (εz) and strain energy density (We). 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.

Effect of trabecular architectures on the mechanical response in osteoporotic and healthy human bone

“…The burgeoning interest in elucidating the architectural arrangement of mesoscale human bone persists, driven by the ongoing alterations in trabecular structure observed throughout the aging process and in pathological conditions. [5,7]. These studies on bone mesoscale structure aim to enhance both the definition of the fabric tissue properties and their relationships with global and local mechanical responses [8].…”

“…Ellipsoid index defines the rod-like or plate-like structure, and it is considered the parameter useful to describe the transition from healthy to pathological bone conditions [27]. The aforementioned morphometric parameters, such as bone density, trabecular thickness, trabecular spacing, connectivity density, anisotropy and ellipsoid factor, are mainly investigated individually, and only few correlations among them in mainly healthy bone conditions are examined in the literature [5,7,12,28]; no correlation and comparison of morphometric parameters in osteoporotic and nonosteoporotic samples is examined. A deep investigation of the mutual associations among morphometric parameters in different physio-pathological state is necessary to provide information useful into clinic.…”

Towards understanding how bisphosphonate‐dependent alterations to nutrient canal integrity can contribute to risk for atypical femoral fractures: Biomechanical considerations and potential relationship to a real‐world analogy

“…To further address this conclusion will likely require the ability to assess the structural and compositional quality of the bone surrounding the altered nutrient canals in femurs. This may be accomplished in part using microCT techniques, [ 38,39 ] but such analysis may require multiple imaging modalities [ 11,40 ] to define specific alterations to the bone, biochemical techniques using post‐mortem tissue samples from areas around the nutrient canals and elsewhere obtained from at risk patients exposed or not exposed to selected BP. Interestingly, there is some literature evidence indicating exposure to BP can impair fracture healing, increasing the risk for delayed or non‐unions.…”

In Vivo Assessment of Skin Surface Pattern: Exploring Its Potential as an Indicator of Bone Biomechanical Properties

“…Therefore, over the past 20 years, researchers have primarily focused on the crystal and collagen quality of bone tissue [11][12][13][14]. Additionally, the effects of patient age and various pathologies have been investigated [15][16][17][18][19]. Recent studies have benefited from the development of new experimental laboratory techniques for material characterization, thus allowing more samples to be analyzed while achieving unprecedented experimental resolutions [20][21][22][23][24][25].…”