Chapter 23. Nanoscale Mechanisms of Bone Deformation and Fracture

  1. Prof. Dr. Edmund Bäuerlein
  1. Peter Fratzl and
  2. Himadri S. Gupta

Published Online: 20 MAR 2008

DOI: 10.1002/9783527619443.ch23

Handbook of Biomineralization: Biological Aspects and Structure Formation

Handbook of Biomineralization: Biological Aspects and Structure Formation

How to Cite

Fratzl, P. and Gupta, H. S. (2007) Nanoscale Mechanisms of Bone Deformation and Fracture, in Handbook of Biomineralization: Biological Aspects and Structure Formation (ed E. Bäuerlein), Wiley-VCH Verlag GmbH, Weinheim, Germany. doi: 10.1002/9783527619443.ch23

Editor Information

  1. Max-Planck-Institute for Biochemistry, Department of Membrane Biochemistry, Am Klopferspitz 18 A, 82152 Planegg, Germany

Publication History

  1. Published Online: 20 MAR 2008
  2. Published Print: 25 MAY 2007

ISBN Information

Print ISBN: 9783527316410

Online ISBN: 9783527619443

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Keywords:

  • bone;
  • collagen;
  • hydroxyapatite;
  • fracture;
  • deformation;
  • synchrotron radiation;
  • diffraction;
  • nanomechanical testing;
  • nanocomposite;
  • toughness

Summary

Bone is a biomineralized tissue with remarkable mechanical performance, specifically a combination of large stiffness with high work to fracture. Whilst the structure of bone is extremely complex and variable, extending over seven or more levels of hierarchy, its basic building block - the mineralized collagen fibril - is rather universal. This consists of staggered arrays of collagen molecules reinforced by nanometer-sized mineral platelets. The mineral is carbonated hydroxya-patite (dahlite), and its amount is usually thought to determine the stiffness of the material. However, the properties of the organic matrix and the geometrical arrangement of the organic and the mineral components at all levels of hierarchy determine the way in which the material deforms and fractures. The hierarchical structure is known to adapt to the biological function of the bone, and plays a critical role in controlling its susceptibility to fracture. In this chapter, the structural features of bone material in the submicrometer range are reviewed, and some recent results on deformation and fracture mechanisms - some obtained with new experimental methods based on the diffraction of synchrotron radiation -are described. A better knowledge of these mechanisms is crucial in order to understand - and hopefully to prevent - osteoporotic fractures. Such knowledge may also serve as inspiration for the development of new bio-inspired composite materials.