title: [Steel or titanium for osteosynthesis : A mechanobiological perspective].
abstract: BACKGROUND
  An implant used for stabilizing a fracture creates a mechanical construct, which directly determines the biology of bone healing. The stabilization of fractures places high mechanical demands on implants and therefore steel and titanium are currently almost exclusively used as the materials of choice.
  
  
  OBJECTIVE
  The possible range of attainable mechanobiological stimulation for mechanotherapy as a function of plate stiffness depending on the selection of the plate material and the physical and mechanical properties of the material options are discussed.
  
  
  METHODS
  An overview of the material properties of steel and titanium is given. For dynamically fixed long bone fractures as examples, various finite element models of plate osteosynthesis (steel/titanium) are created and the plate working length (PWL, screw configuration close to fracture) is varied. The interfragmentary movement (IFM) as a measure of mechanobiological stimulation is evaluated.
  
  
  RESULTS
  Stimulation in the form of IFM varies across the fracture and also as a function of the osteosynthesis material and the configuration. The influence of the material appears to be notably smaller than the influence of PWL but both lose their influence largely over a bridged fracture situation (contact). With a flexible titanium plate and large PSS, a greater mechanobiological stimulation is produced.
  
  
  CONCLUSIONS
  An essential prerequisite for the secondary fracture healing is an appropriate mechanobiological environment, which can be controlled by the osteosynthesis material and the configuration and is also affected by the type of fracture and load.
authors.affiliation: Julius Wolff Institut, Campus-Virchow-Klinikum, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, Institutsgebäude Süd, 13353, Berlin, Deutschland.
authors.forename: M
authors.initials: M
authors.lastname: Heyland
authors.affiliation: Julius Wolff Institut, Campus-Virchow-Klinikum, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, Institutsgebäude Süd, 13353, Berlin, Deutschland. georg.duda@charite.de.
authors.forename: G N
authors.initials: GN
authors.lastname: Duda
authors.affiliation: CMSC - Centrum für Muskuloskeletale Chirurgie, Charité-Universitätsmedizin Berlin, Berlin, Deutschland.
authors.forename: S
authors.initials: S
authors.lastname: Märdian
authors.affiliation: CMSC - Centrum für Muskuloskeletale Chirurgie, Charité-Universitätsmedizin Berlin, Berlin, Deutschland.
authors.forename: M
authors.initials: M
authors.lastname: Schütz
authors.affiliation: AO Forschungsinstitut Davos, Davos, Schweiz.
authors.forename: M
authors.initials: M
authors.lastname: Windolf
mesh_terms: D000818:Animals; D003198:Computer Simulation; D055119:Elastic Modulus; D017102:Fracture Healing / Q000502:physiology*; D050723:Fractures, Bone / Q000503:physiopathology* / Q000628:therapy*; D006801:Humans; D008422:Materials Testing; D008954:Models, Biological; D011474:Prosthesis Design; D013232:Steel / Q000737:chemistry*; D013314:Stress, Mechanical; D014025:Titanium / Q000737:chemistry*
chemical_list: D013232:Steel; D014025:Titanium
keywords: Fixation stiffness; Interfragmentary movement; Mechanobiology; Mechanotherapy; Osteosynthesis material