The bending properties of single osteons

Fracture of bone tissue: The ‘hows’ and the ‘whys’

“…Rather surprisingly, isolated osteons in compression [52] were half as stiff (6-7 GPa) but nearly as strong as osteons in tension . Bending tests gave even lower values [53] for stiffness of approximately 2-3 GPa and bending strength of 350-390 MPa, while torsional tests [54] gave moduli of 16-20 and strengths of 160-200 MPa. While this dependence of mechanical properties depending on the testing mode may be because different deformation processes in the anisotropic bone tissue are activated, based on the direction of deformation, the bending results especially should be interpreted with caution.…”

“…At the level of the entire osteon (Haversian system), our knowledge of the mechanical properties comes mainly from the pioneering work of Ascenzi et al, who examined the mechanical properties in tension [51], compression [52], bending [53] and torsion [54]. Differences were observed in tension for the osteons classified as "longitudinal" (fibrils oriented parallel to the osteon axis) and "transverse" (fibrils oriented perpendicular to the osteon axis).…”

Understanding the structure–property relationship in cortical bone to design a biomimetic composite

“…At macroscale, conventional testing [2][3][4]6,7,9,10,16,[25][26][27][28][29], but also ultrasounds [12,30] have been used to characterize cortical and trabecular tissues, showing a clear anisotropy of bone; At microscale, Ascenzi and co-workers [31][32][33][34][35] other authors used micromechanical testing [7,36,37] and acoustic microscopy [15,38,39] to evaluate the elastic properties of bone at the microstructural level; At nanoscale, the most common technique used to characterize bone tissue is nanoindentation [13][14][15]40,41]. Moreover, novel less invasive methodologies for in vivo measuring fracture toughness on small animals are of great clinical relevance, since they can be helpful in understanding the material properties of bone during preclinical testing for reducing fracture risks [42]; At nano-to subnanoscale, numerical simulations -from atomistic to coarse grain -allow researchers to examine the small scale chemo-mechanical behavior, studying characteristic phenomena, which are difficult to be reached by experiments [43].…”

Regression Analysis of Fracture Toughness for Secondary Osteons Located in Human Cortical Bone

“…(3)(4)(5)(6)(7)(8)(9)(10)(11)(12) There were three main objectives that this experiment intended to cover; they all had to be completed in a particular order, because the first step was necessary for the second and third.…”

“…(Bone transparency can be increased to some extent by soaking the section in bromoform. (3)(4)(5)(6)(7)(8) Among the earliest to investigate the identifying and cataloging of osteons were Bonucci (1965, 1964) who discovered and classed three distinct types using a polarizing microscope and the theory of birefringence. In the first type, the fibers had a marked longitudinal spiral course with the pitch of the spiral changing so slightly that the angle of the fibers in one lamella was practically the same as that of the fibers of the next lamella.…”