title: Time Dependent Behaviour of Trabecular Bone at Multiple Load Levels.
abstract: The deformation of bone when subjected to loads is not instantaneous but varies with time. To investigate this time-dependent behaviour sixteen bovine trabecular bone specimens were subjected to compressive loading, creep, unloading and recovery at multiple load levels corresponding to apparent strains of 2000-25,000 με. We found that: the time-dependent response of trabecular bone comprises of both recoverable and irrecoverable strains; the strain response is nonlinearly related to applied load levels; and the response is linked to bone volume fraction. Although majority of strain is recovered after the load-creep-unload-recovery cycle some residual strain always exists. The analysis of results indicates that trabecular bone becomes stiffer initially and then experiences stiffness degradation with the increasing load levels. Steady state creep rate was found to be dependent on applied stress level and bone volume fraction with a power law relationship.
authors.affiliation: Institute for Bioengineering, School of Engineering, The University of Edinburgh, King's Buildings, Edinburgh, EH9 3DW, UK.
authors.forename: Shuqiao
authors.initials: S
authors.lastname: Xie
authors.affiliation: Institute for Bioengineering, School of Engineering, The University of Edinburgh, King's Buildings, Edinburgh, EH9 3DW, UK.
authors.forename: Krishnagoud
authors.initials: K
authors.lastname: Manda
authors.affiliation: Department of Orthopaedics, The University of Edinburgh, Chancellor's Building, Edinburgh, EH16 4SB, UK.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Wallace
authors.affiliation: Institute for Bioengineering, School of Engineering, The University of Edinburgh, King's Buildings, Edinburgh, EH9 3DW, UK.
authors.forename: Francesc
authors.initials: F
authors.lastname: Levrero-Florencio
authors.affiliation: Department of Orthopaedics, The University of Edinburgh, Chancellor's Building, Edinburgh, EH16 4SB, UK.
authors.forename: A Hamish R W
authors.initials: AHRW
authors.lastname: Simpson
authors.affiliation: Institute for Bioengineering, School of Engineering, The University of Edinburgh, King's Buildings, Edinburgh, EH9 3DW, UK. pankaj@ed.ac.uk.
authors.forename: Pankaj
authors.identifier: 0000-0002-9317-3909
authors.initials: P
authors.lastname: Pankaj
mesh_terms: D000818:Animals; D002417:Cattle; D005260:Female; D005264:Femoral Fractures / Q000503:physiopathology*; D005269:Femur / Q000503:physiopathology*; D013314:Stress, Mechanical; D016474:Weight-Bearing
keywords: Bone volume fraction; Creep compliance; Creep-recovery; Steady state creep rate; Viscoelastic