Cortical Bone Fracture

Abstract

Data are given in either K or G as reported by the authors. All reported values are mean values, standard deviations are given when possible. } When specific orientation is unknown, cracking direction is given, see Fig. 2 for details. *Range of mean values for several sets of data from samples tested at different loading rates.w Range of mean values for two sets of data using samples of different thickness.z Range of mean values for three sets of data using samples from different age groups. # Range of mean values for two sets of data using samples stored in different media.

Effects of age and loading rate on equine cortical bone failure

“…Examining the microstructure of the bone (where the undamaged bone is imaged blue by the autofluorescence of bone, and the fracture path green by calcein), it is apparent how the microstructure deflects the crack along cement lines and away from the most direct crack path. Extensive peripheral damage is also evident along the crack path, demonstrating the large amount of surrounding damage caused during crack propagation by cement line deflection and unbroken ligament bridging (Nalla et al, 2003(Nalla et al, , 2004a(Nalla et al, , 2005a(Nalla et al, , 2004b(Nalla et al, , 2005bRitchie et al, 2006), as well as micro-cracking Vashishth et al, 1997Vashishth et al, , 2000 ahead of the crack tip. Another feature of note highlighted in this fracture path is the extensive labeling of what appears to be a Volksmann's canal in the lower right region of Fig.…”

“…Donor age has also been shown to have a distinct influence on the quasi-static fracture behavior of cortical bone. However, what causes this change is not fully understood; collagen properties, increased mineralization, bulk density and secondary osteon concentration and size all appear to be important factors Nalla et al, 2006Nalla et al, , 2004aRitchie et al, 2006;Wang et al, 2002bWang et al, , 1998Zioupos and Currey, 1998;Zioupos et al, 1996).…”

Aging and loading rate effects on the mechanical behavior of equine bone

“…1 Built up of successive structures varying from the nano-to the macro-scale, the main constituents of collagen and calcium phosphate mineral interact to produce a highly specialized material that supports bodily loads, resists fracture, self heals, and blends fl awlessly with tendons and ligaments. [2][3][4] It has even been shown to adapt locally to better manage biomechanical loads experienced within individual bones. 5,6 However, despite decades of research on the me-aging and Loading rate effects on the mechanical behavior of equine bone Robb M. Kulin, Fengchun Jiang, and Kenneth S. Vecchio chanical behavior of bone, how this structure interacts at its various levels to perform these functions is still poorly understood.…”

Development of hydroxyapatite/calcium silicate composites addressed to the design of load-bearing bone scaffolds

“…One of the possible loading naturally occurring in vivo is a tensile-opening loading (Ritchie et al, 2006); in this frame, the behaviour of the sintered HA and composites was investigated by the Chevron notch method (Munz et al, 1980) for the measurement of the fracture toughness K IC , which is related to this particular loading.…”