title: Evaluation of composition and mineral structure of callus tissue in rat femoral fracture.
abstract: Callus formation is a critical step for successful fracture healing. Little is known about the molecular composition and mineral structure of the newly formed tissue in the callus. The aim was to evaluate the feasibility of small angle x-ray scattering (SAXS) to assess mineral structure of callus and cortical bone and if it could provide complementary information with the compositional analyses from Fourier transform infrared (FTIR) microspectroscopy. Femurs of 12 male Sprague-Dawley rats at 9 weeks of age were fractured and fixed with an intramedullary 1.1 mm K-wire. Fractures were treated with the combinations of bone morphogenetic protein-7 and/or zoledronate. Rats were sacrificed after 6 weeks and both femurs were prepared for FTIR and SAXS analysis. Significant differences were found in the molecular composition and mineral structure between the fracture callus, fracture cortex, and control cortex. The degree of mineralization, collagen maturity, and degree of orientation of the mineral plates were lower in the callus tissue than in the cortices. The results indicate the feasibility of SAXS in the investigation of mineral structure of bone fracture callus and provide complementary information with the composition analyzed with FTIR. Moreover, this study contributes to the limited FTIR and SAXS data in the field.
authors: University of Eastern Finland, Department of Applied Physics, POB 1627, FIN-70211 Kuopio, Finland.
authors: Mikael J
authors: MJ
authors: Turunen
authors: Lund University, Division of Physical Chemistry, POB 124, SE-22100 Lund, Sweden.
authors: Sebastian
authors: S
authors: Lages
authors: Lund University, MAX IV Laboratory, POB 118, SE-22100 Lund, Sweden.
authors: Ana
authors: A
authors: Labrador
authors: Lund University, Division of Physical Chemistry, POB 124, SE-22100 Lund, Sweden.
authors: Ulf
authors: U
authors: Olsson
authors: Lund University, Department of Orthopaedics, Clinical Sciences, POB 118, SE-22100 Lund, Sweden.
authors: Magnus
authors: M
authors: Tägil
authors: University of Eastern Finland, Department of Applied Physics, POB 1627, FIN-70211 Kuopio, Finland.
authors: Jukka S
authors: JS
authors: Jurvelin
authors: University of Eastern Finland, Department of Applied Physics, POB 1627, FIN-70211 Kuopio, FinlanddLund University, Department of Orthopaedics, Clinical Sciences, POB 118, SE-22100 Lund, SwedeneLund University, Division of Solid Mechanics, POB 118, SE-2210.
authors: Hanna
authors: H
authors: Isaksson
mesh_terms: D000818:Animals; D019485:Bone Morphogenetic Proteins / Q000032:analysis / Q000737:chemistry; D002146:Bony Callus / Q000737:chemistry* / Q000502:physiology; D005264:Femoral Fractures / Q000378:metabolism / Q000503:physiopathology*; D005269:Femur / Q000737:chemistry*; D017102:Fracture Healing / Q000502:physiology; D008297:Male; D008903:Minerals / Q000032:analysis* / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D053838:Scattering, Small Angle; D012965:Sodium Chloride / Q000032:analysis / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction; D055114:X-Ray Microtomography
chemical_list: D019485:Bone Morphogenetic Proteins; D008903:Minerals; D012965:Sodium Chloride