title: Skeletal maturity leads to a reduction in the strain magnitudes induced within the bone: a murine tibia study.
abstract: Bone adapts to changes in the local mechanical environment (e.g. strains) through formation and resorption processes. However, the bone adaptation response is significantly reduced with increasing age. The mechanical strains induced within the bone by external loading are determined by bone morphology and tissue material properties. Although it is known that changes in bone mass, architecture and bone tissue quality occur with age, to what extent they contribute to the altered bone adaptation response remains to be determined. This study investigated alterations in strains induced in the tibia of different aged female C57Bl/6J mice (young, 10-week-old; adult, 26-week-old; and elderly, 78-week-old) subjected to in vivo compressive loading. Using a combined in vivo/in silico approach, the strains in the bones were assessed by both strain gauging and finite element modeling experiments. In cortical bone, strain magnitudes induced at the mid-diaphysis decreased by 20% from young to adult mice and by 15% from adult to elderly mice. In the cancellous bone (at the proximal metaphysis), induced strains were 70% higher in young compared with adult and elderly mice. Taking into account previous studies showing a reduced bone adaptation response to mechanical loading in adulthood, these results suggest that the diminished adaptive response is in part due to a reduction in the strains induced within the bone.
authors.affiliation: Julius Wolff Institute, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Institutsgebäude Süd/Südstraße 2, Augustenburger Platz 1, 13353 Berlin, Germany.
authors.forename: Hajar
authors.initials: H
authors.lastname: Razi
authors.affiliation: Julius Wolff Institute, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Institutsgebäude Süd/Südstraße 2, Augustenburger Platz 1, 13353 Berlin, Germany.
authors.forename: Annette I
authors.initials: AI
authors.lastname: Birkhold
authors.affiliation: Julius Wolff Institute, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Institutsgebäude Süd/Südstraße 2, Augustenburger Platz 1, 13353 Berlin, Germany; Berlin-Brandenburg Center for Regenerative Therapies, Berlin, Germany.
authors.forename: Paul
authors.initials: P
authors.lastname: Zaslansky
authors.affiliation: Max Planck Institute of Colloids and Interfaces, Potsdam, Germany.
authors.forename: Richard
authors.initials: R
authors.lastname: Weinkamer
authors.affiliation: Julius Wolff Institute, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Institutsgebäude Süd/Südstraße 2, Augustenburger Platz 1, 13353 Berlin, Germany; Berlin-Brandenburg Center for Regenerative Therapies, Berlin, Germany.
authors.forename: Georg N
authors.initials: GN
authors.lastname: Duda
authors.affiliation: Julius Wolff Institute, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Institutsgebäude Süd/Südstraße 2, Augustenburger Platz 1, 13353 Berlin, Germany.
authors.forename: Bettina M
authors.initials: BM
authors.lastname: Willie
authors.affiliation: Julius Wolff Institute, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Institutsgebäude Süd/Südstraße 2, Augustenburger Platz 1, 13353 Berlin, Germany. Electronic address: sara.checa@charite.de.
authors.forename: Sara
authors.initials: S
authors.lastname: Checa
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D005260:Female; D051379:Mice; D013977:Tibia / Q000502:physiology*; D016474:Weight-Bearing
keywords: Age; Finite element modeling; Mechanical strains; Mouse tibial compression