title: Microstructure and compressive mechanical properties of cortical bone in children with osteogenesis imperfecta treated with bisphosphonates compared with healthy children.
abstract: Osteogenesis imperfecta (OI) is a genetic disorder characterized by a change in bone tissue quality, but little data are available to describe the factors involved at the macroscopic scale. To better understand the effect of microstructure alterations on the mechanical properties at the sample scale, we studied the structural and mechanical properties of six cortical bone samples from children with OI treated with bisphosphonates and compared them to the properties of three controls. Scanning electron microscopy, high resolution computed tomography and compression testing were used to assess these properties. More resorption cavities and a higher osteocyte lacunar density were observed in OI bone compared with controls. Moreover, a higher porosity was measured for OI bones along with lower macroscopic Young's modulus, yield stress and ultimate stress. The microstructure was impaired in OI bones; the higher porosity and osteocyte lacunar density negatively impacted the mechanical properties and made the bone more prone to fracture.
authors.affiliation: LTDS UMR CNRS 5513, Ecole Centrale Lyon, 36 avenue Guy de Collongue, 69134 Ecully, France.
authors.forename: Laurianne
authors.initials: L
authors.lastname: Imbert
authors.affiliation: Department of Pediatric Orthopedics, Necker-Enfants Malades Hospital, AP-HP, Paris Descartes University, 145 rue de Sèvres, 75014 Paris, France; B2OA UMR CNRS 7052, University Paris-Diderot, 10 avenue de Verdun, 75010 Paris, France.
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Aurégan
authors.affiliation: LTDS UMR CNRS 5513, Ecole Centrale Lyon, 36 avenue Guy de Collongue, 69134 Ecully, France.
authors.forename: Kélig
authors.initials: K
authors.lastname: Pernelle
authors.affiliation: LTDS UMR CNRS 5513, Ecole Centrale Lyon, 36 avenue Guy de Collongue, 69134 Ecully, France. Electronic address: thierry.hoc@ec-lyon.fr.
authors.forename: Thierry
authors.initials: T
authors.lastname: Hoc
mesh_terms: D000293:Adolescent; D015519:Bone Density / Q000187:drug effects; D001842:Bone and Bones / Q000166:cytology* / Q000187:drug effects / Q000473:pathology* / Q000503:physiopathology; D016022:Case-Control Studies; D002648:Child; D019245:Compressive Strength / Q000187:drug effects; D004164:Diphosphonates / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008422:Materials Testing; D010013:Osteogenesis Imperfecta / Q000188:drug therapy* / Q000473:pathology* / Q000503:physiopathology; D016062:Porosity; D055815:Young Adult
chemical_list: D004164:Diphosphonates
keywords: Bone mineral density; High resolution X-ray computed tomography; Mechanical properties; Osteocyte lacunae density; Osteogenesis imperfecta; Porosity