Effect of Bone Composition on the Fracture Toughness of Cortical Bone

Abstract

This study was aimed at investigating the effect of the bone compositions on the fracture toughness of bovine cortical bone. A series of the SENB bovine cortical bone specimens were tested to assess the fracture toughness. Dual energy X-ray absorptiometry (DEXA) was applied to determine the mineral content of each bovine cortical specimen and hence the porosity and bone mineral fraction were measured. Current results indicate that the mean value fracture toughness is 9.37 MNm3/2. Moreover, the fracture toughness was found to be significantly correlated with the apparent wet bone density and porosity of bone structure. No apparent correlations are found among clinical BMD and mechanical properties, implying that the BMD is an invalid indicator of the bone properties. Additionally, the tested data were fitted to the relationship, based on power law model, that the fracture toughness increase as a power (1.526) of increasing volume fraction and as a power of increasing bone mineral fraction (0.8195). These data indicate that small changes in the amount or density of compact bone tissue exert a more pronounced influence on fracture property.

A review on experimental and numerical investigations of cortical bone fracture

“…31 Numerous experimental studies determined the effect of several parameters, that is, sugar, age, hydration, mineralization, preservative method, fatigue loading, strain rate, porosity, anisotropy, demineralization, deproteinization, type of specimen, indentation, shear deformation, bone composition, etc., on fracture parameters of cortical bone. 21–23,32–64 Many researchers have validated their numerically predicted results with the experimental analysis as well. 22,40,42,47,51,62…”

“…All the mentioned studies in this review have considered wet bone. Therefore, studies on bovine and human bone have indicated the increment in K C of cortical bone with increasing dry and wet density 23,26,40,41,50,61,108,126–128 and decrease in K C with increasing mineral content or porosity. 110,111,129 Mineralization and moisture are the foremost aspects affecting the mechanical response of the compact bone.…”