Study of the cortical bone strength affectation due dehydration

A study in cortical bovine bones with collagen quality affectation by the air-dried technique is presented. An out of plane digital holographic interferometer is used to retrieve the optical phase during controlled compression tests on cortical bone samples. This test simulates physiological deformations in post-mortem healthy bone tissue and compares their surface response with those affected by the dehydration mentioned processes. Recent studies have demonstrated that bone strength must be understood as an integral concept that depends on quantity, quality and turnover of the bone. Considering that several diseases and conditions could affect not only the inorganic (hydroxyapatite) but also the organic (collagen and water) components of the bone, it is critical to isolate each affecting effect during the optical tests. Water comprises about 20 % of the bone's volume and is a key determinant of its structural mechanical behavior, i.e., it is responsible for giving the collagen its ability to confer ductility or plasticity to the bone. The results presented in this talk analyze the micro structural variations of the bone strength due to the resulting optical phase variations as obtained from the tested bulk samples. Several tests were performed to register the profiles and ranges of the displacements during the compressive loads which are expressed in terms of wrapped optical phase. A discussion is presented.