title: Effect of low-intensity pulsed ultrasound stimulation on gap healing in a rabbit osteotomy model evaluated by quantitative micro-computed tomography-based cross-sectional moment of inertia.
abstract: BACKGROUND
  It has been previously demonstrated that low-intensity pulsed ultrasound stimulation (LIPUS) enhances formation of the medullary canal and cortex in a gap-healing model of the tibia in rabbits, shortens the time required for remodeling, and enhances mineralization of the callus. In the current study, the mechanical integrity of these models was confirmed. In order to do this, the cross-sectional moment of inertia (CSMI) obtained from quantitative micro-computed tomography scans was calculated, and a comparison was made with a four-point bending test.
  
  
  METHODS
  This parameter can be analyzed in any direction, and three directions were selected in order to adopt an XYZ coordinate (X and Y for bending; Z for torsion).
  
  
  RESULTS
  The present results demonstrated that LIPUS improved earlier restoration of bending stiffness at the healing site. In addition, LIPUS was effective not only in the ultrasound-irradiated plane, but also in the other two planes.
  
  
  CONCLUSIONS
  CSMI may provide the structural as well as compositional determinants to assess fracture healing and would be very useful to replace the mechanical testing.
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. tobitak.ort@gmail.com
authors.forename: Kenji
authors.initials: K
authors.lastname: Tobita
authors.forename: Takuya
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Satoru
authors.initials: S
authors.lastname: Ohashi
authors.forename: Masahiko
authors.initials: M
authors.lastname: Bessho
authors.forename: Masako
authors.initials: M
authors.lastname: Kaneko
authors.forename: Isao
authors.initials: I
authors.lastname: Ohnishi
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D016723:Bone Remodeling / Q000502:physiology; D017102:Fracture Healing / Q000502:physiology*; D008297:Male; D010027:Osteotomy; D011817:Rabbits; D013314:Stress, Mechanical; D013977:Tibia / Q000000981:diagnostic imaging / Q000601:surgery*; D014464:Ultrasonic Therapy / Q000379:methods*; D055114:X-Ray Microtomography