Comparative characteristic of the methods of certification of deformed microstructure of trabecular bone tissue

The article analyzes the data of microscopic studies of human trabecular bone tissue. Differences in the deformation behavior are due to the morphology of the organic and mineral components of the extracellular matrix at all structural levels of the hierarchical organization of bone tissue. The purpose of the work was to determine the most informative microscopic method for certifying the deformed microstructure of trabecular bone tissue in terms of the mechanism of its formation at the microlevel. Proceeding from the localization of the appearance of impression fractures, the bone tissue of the lateral condyle of the tibial bone was taken for examination. All samples were divided into two groups: basic ( N = 20, 50.0%), in which each sample was subjected to uniaxial compression; the control group ( N = 20, 50.0%) was intact to the methods of studying the deformation behavior. For the certification of osteoarchitecture, modern visualization methods are applied: raster electron microscopy and atomic force microscopy. A detailed description is given of the deformation behavior of trabecular bone under uniaxial compression as the morphological substrate of impression defects. Photos of morphological changes during uniaxial compression are presented at the macroscopic, intermediate, and microscopic levels of organization of the extracellular matrix of bone tissue. It is established that trabecular bone tissue is a plastic material at all levels of the organization of the extracellular matrix. The morphological substrate of microfracture was determined at each structural level: macroscopic (100-200 µm) level - transverse, longitudinal, and fragmented trabeculae fractures; mesoscopic (10-50 µm) - interlamellar cracks observed in trabeculae; microscopic (5-10 µm) - the lamella is disorganized by collagen fibrils, the interfibrillar gaps are reduced, the hydroxyapatite crystals are disrupted and their bonds with collagen are destroyed. Each type of research complements data from other types of microscopy, none of them can completely replace the others.