Tissue-Level Mechanical Properties of Bone Contributing to Fracture Risk.
Tissue-level mechanical properties characterize mechanical behavior independently of microscopic porosity. Specifically, quasi-static nanoindentation provides measurements of modulus (stiffness) and hardness (resistance to yielding) of tissue at the length scale of the lamella, while dynamic nanoindentation assesses time-dependent behavior in the form of storage modulus (stiffness), loss modulus (dampening), and loss factor (ratio of the two). While these properties are useful in establishing how a gene, signaling pathway, or disease of interest affects bone tissue, they generally do not vary with aging after skeletal maturation or with osteoporosis. Heterogeneity in tissue-level mechanical properties or in compositional properties may contribute to fracture risk, but a consensus on whether the contribution is negative or positive has not emerged. In vivo indentation of bone tissue is now possible, and the mechanical resistance to microindentation has the potential for improving fracture risk assessment, though determinants are currently unknown.
Department of Orthopaedic Surgery and Rehabilitation, Vanderbilt University Medical Center, 1215 21st Ave. S., South Tower, Suite 4200, Nashville, TN, 37232, USA. jeffry.s.nyman@vanderbilt.edu.|Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, TN, 37212, USA. jeffry.s.nyman@vanderbilt.edu.|Center for Bone Biology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA. jeffry.s.nyman@vanderbilt.edu.|Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, 37232, USA. jeffry.s.nyman@vanderbilt.edu.
Jeffry S
JS
Nyman
Department of Orthopaedic Surgery and Rehabilitation, Vanderbilt University Medical Center, 1215 21st Ave. S., South Tower, Suite 4200, Nashville, TN, 37232, USA.|Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, TN, 37212, USA.|Center for Bone Biology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA.
Mathilde
M
Granke
Materials Science and Engineering Department, University of Tennessee, Knoxville, TN, 37996, USA.
Robert C
RC
Singleton
Materials Science and Engineering Department, University of Tennessee, Knoxville, TN, 37996, USA.|Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
George M
GM
Pharr
D001696:Biomechanical Phenomena; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology*; D055119:Elastic Modulus; D050723:Fractures, Bone / Q000453:epidemiology / Q000378:metabolism / Q000503:physiopathology*; D006244:Hardness; D006801:Humans; D012306:Risk; D000073798:Second Harmonic Generation Microscopy; D017550:Spectroscopy, Fourier Transform Infrared; D013057:Spectrum Analysis; D013059:Spectrum Analysis, Raman
Bone quality; Bound water; Hardness; Nanoindentation; Spectroscopy; Viscoelasticity