title: The influence of low-intensity physiotherapeutic ultrasound on the initial stage of bone healing in rats: an experimental and simulation study.
abstract: BACKGROUND
  Low-intensity physiotherapeutic ultrasound has been used in physical therapy clinics; however, there remain some scientific issues regarding the bone-healing process. The objective of this study was to investigate the influence of low-intensity physiotherapeutic ultrasound on the initial stage of bone healing in rats.
  
  
  METHODS
  Twenty-two male adult rats were assessed quantitatively and qualitatively using radiographic, biochemical, and histological analyses. Numerical simulations were also performed. Fractures in animals in the ultrasound group (n= 11) were treated with low-intensity ultrasound (pulsed mode, duty cycle 20 %) for 10 min daily at an intensity of 40 mW/cm2SATA (1.0 MHz) for 10 days. Fractures in animals in the control group (n= 11) were not treated.
  
  
  RESULTS
  Alkaline phosphatase levels were non-significantly higher in the ultrasound group than in the control group in the time intervals considered (t(13) = 0.440; 95 % confidence interval (CI) -13.79 to 20.82;p= 0.67). Between-group serum calcium levels were also not significantly different (t(13) = -0.842; 95 % CI -0.48 to 0.21;p= 0.42). Finally, there were no significant differences in radiological scores between the two groups (U= 118; 95 % CI -1.99 to 1.99;p= 0.72). However, the diameter of the newly formed bone tissue was greater and more evident in the ultrasound group.
  
  
  CONCLUSIONS
  Thirteen days after fracture, there was no significant between-group differences in bone-healing processes, although the increased alkaline phosphatase levels and diameter of new bone tissue need to be further investigated.
authors.affiliation: Ultrasound Laboratory, Biomedical Engineering Program/COPPE/Federal University of Rio de Janeiro - UFRJ, Rio de Janeiro, Rio de Janeiro Brazil.
authors.forename: Aldo José
authors.initials: AJ
authors.lastname: Fontes-Pereira
authors.affiliation: Laboratory of Morpho-physiopathology, State University of Pará, Belém, Pará Brazil.
authors.forename: Marcio
authors.initials: M
authors.lastname: Amorim
authors.affiliation: Ultrasound Laboratory, Biomedical Engineering Program/COPPE/Federal University of Rio de Janeiro - UFRJ, Rio de Janeiro, Rio de Janeiro Brazil.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Catelani
authors.affiliation: Military Police Central Hospital of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro Brazil.
authors.forename: Daniel Patterson
authors.initials: DP
authors.lastname: Matusin
authors.affiliation: Ultrasound Laboratory, Biomedical Engineering Program/COPPE/Federal University of Rio de Janeiro - UFRJ, Rio de Janeiro, Rio de Janeiro Brazil.
authors.forename: Paulo
authors.initials: P
authors.lastname: Rosa
authors.affiliation: Laboratory of Epithelial Biology, Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI USA.
authors.forename: Douglas Magno
authors.initials: DM
authors.lastname: Guimarães
authors.affiliation: Ultrasound Laboratory, Biomedical Engineering Program/COPPE/Federal University of Rio de Janeiro - UFRJ, Rio de Janeiro, Rio de Janeiro Brazil.
authors.forename: Marco Antônio
authors.initials: MA
authors.lastname: von Krüger
authors.affiliation: Ultrasound Laboratory, Biomedical Engineering Program/COPPE/Federal University of Rio de Janeiro - UFRJ, Rio de Janeiro, Rio de Janeiro Brazil.
authors.forename: Wagner Coelho de Albuquerque
authors.initials: WC
authors.lastname: Pereira
keywords: Bone; Fracture healing; Physical therapy; Ultrasonic therapy