title: Mapping dynamical mechanical properties of osteonal bone by scanning acoustic microscopy in time-of-flight mode.
abstract: An important determinant of mechanical properties of bone is Young's modulus and its variation in individual osteons of cortical bone tissue. Its mechanical behavior also depends on deformation rate owing to its visco- or poroelastic properties. We developed a method to measure dynamical mechanical properties of bulk bone tissue at osteonal level based on scanning acoustic microscopy (SAM) using time-of-flight (TOF) measurements in combination with quantitative backscattered electron imaging (qBEI). SAM-TOF yields local sound velocities and qBEI corresponding material densities together providing elastic properties. Osteons (n=55) were measured in three human femoral diaphyseal ground bone sections (∼ 30 µm in thickness). In addition, subchondral bone and mineralized articular cartilage were investigated. The mean mineral contents, the mean sound velocities, and the mean elastic modulus of the osteons ranged from 20 to 26 wt%, from 3,819 to 5,260 m/s, and from 21 to 44 GPa, respectively. There was a strong positive correlation between material density and sound velocity (Pearson's r=0.701; p<0.0001) of the osteons. Sound velocities between cartilage and bone was similar, though material density was higher in cartilage (+4.46%, p<0.0001). These results demonstrate the power of SAM-TOF to estimate dynamic mechanical properties of the bone materials at the osteonal level.
authors.affiliation: 11st Medical Department,Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of WGKK and AUVA Trauma Centre Meidling,Hanusch Hospital,Heinrich Collin Str. 30,A-1140 Vienna,Austria.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Blouin
authors.affiliation: 2Faculty of Physics,University of Vienna,Dynamics of Condensed Systems,Strudlhofgasse 4,A-1090 Vienna,Austria.
authors.forename: Stephan
authors.initials: S
authors.lastname: Puchegger
authors.affiliation: 11st Medical Department,Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of WGKK and AUVA Trauma Centre Meidling,Hanusch Hospital,Heinrich Collin Str. 30,A-1140 Vienna,Austria.
authors.forename: Andreas
authors.initials: A
authors.lastname: Roschger
authors.affiliation: 3Department of Forensics,Medical University of Vienna,Sensengasse 2,A-1090 Vienna,Austria.
authors.forename: Andrea
authors.initials: A
authors.lastname: Berzlanovich
authors.affiliation: 4Department of Biomaterials,Max Planck Institute of Colloids and Interfaces,14424 Potsdam,Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Fratzl
authors.affiliation: 11st Medical Department,Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of WGKK and AUVA Trauma Centre Meidling,Hanusch Hospital,Heinrich Collin Str. 30,A-1140 Vienna,Austria.
authors.forename: Klaus
authors.initials: K
authors.lastname: Klaushofer
authors.affiliation: 11st Medical Department,Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of WGKK and AUVA Trauma Centre Meidling,Hanusch Hospital,Heinrich Collin Str. 30,A-1140 Vienna,Austria.
authors.forename: Paul
authors.initials: P
authors.lastname: Roschger
mesh_terms: D001842:Bone and Bones / Q000737:chemistry / Q000502:physiology*; D055598:Chemical Phenomena; D004548:Elasticity; D005269:Femur / Q000737:chemistry / Q000502:physiology; D006253:Haversian System / Q000737:chemistry / Q000502:physiology*; D006801:Humans; D055595:Mechanical Phenomena; D033401:Microscopy, Acoustic / Q000379:methods*; D046032:Microscopy, Energy-Filtering Transmission Electron / Q000379:methods; D008903:Minerals / Q000032:analysis
chemical_list: D008903:Minerals