title: Techniques to assess bone ultrastructure organization: orientation and arrangement of mineralized collagen fibrils.
abstract: Bone's remarkable mechanical properties are a result of its hierarchical structure. The mineralized collagen fibrils, made up of collagen fibrils and crystal platelets, are bone's building blocks at an ultrastructural level. The organization of bone's ultrastructure with respect to the orientation and arrangement of mineralized collagen fibrils has been the matter of numerous studies based on a variety of imaging techniques in the past decades. These techniques either exploit physical principles, such as polarization, diffraction or scattering to examine bone ultrastructure orientation and arrangement, or directly image the fibrils at the sub-micrometre scale. They make use of diverse probes such as visible light, X-rays and electrons at different scales, from centimetres down to nanometres. They allow imaging of bone sections or surfaces in two dimensions or investigating bone tissue truly in three dimensions, in vivo or ex vivo, and sometimes in combination with in situ mechanical experiments. The purpose of this review is to summarize and discuss this broad range of imaging techniques and the different modalities of their use, in order to discuss their advantages and limitations for the assessment of bone ultrastructure organization with respect to the orientation and arrangement of mineralized collagen fibrils.
authors.affiliation: Institute for Biomechanics, ETH Zurich, Zurich, Switzerland.
authors.forename: Marios
authors.initials: M
authors.lastname: Georgiadis
authors.affiliation: Institute for Biomechanics, ETH Zurich, Zurich, Switzerland.
authors.forename: Ralph
authors.initials: R
authors.lastname: Müller
authors.affiliation: Institute for Biomechanics, ETH Zurich, Zurich, Switzerland Bioengineering Science Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton, UK p.schneider@soton.ac.uk.
authors.forename: Philipp
authors.initials: P
authors.lastname: Schneider
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods*; D000818:Animals; D001842:Bone and Bones / Q000378:metabolism / Q000648:ultrastructure; D002113:Calcification, Physiologic / Q000502:physiology*; D003094:Collagen / Q000378:metabolism*; D006801:Humans
chemical_list: D003094:Collagen
keywords: bone imaging; bone ultrastructure organization; collagen orientation; crystal orientation; mineralized collagen fibrils; ultrastructure orientation and arrangement