title: Effect of low-intensity pulsed ultrasound on bone regeneration: biochemical and radiologic analyses.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the effects of low-intensity pulsed ultrasound at 1.0 MHz on the healing process of fractures with bone loss in the rat fibula by alkaline phosphate level measurement and radiologic analyses.
  
  
  METHODS
  Thirty 70-day-old male Wistar rats underwent a bone resection of 2.5 to 3.0 mm between the proximal and middle third of the right fibular diaphysis. The animals were randomly divided into 3 experimental groups: reference (uninjured), control (injured only), and treated (injured and treated with 5 applications of ultrasound, interspersed by 2 days of rest, beginning 24 hours after the osteotomy). Euthanasia was performed at experimental periods of 7 and 14 days. The right hind limb was removed for radiologic analysis. The blood was collected via cardiac puncture to determine the serum alkaline phosphatase activity.
  
  
  RESULTS
  The bone fractures had not been completely consolidated in the treated and control group when analysis of the bone took place. At day 7, the serum alkaline phosphatase activity was higher in the treated group (mean ± SD, 72.17 ± 7.02 U/L) compared to the control (65.26 ± 8.41 U/L) and reference (67.21 ± 7.86 U/L) groups. At day 14, higher alkaline phosphatase activity was seen in the control group (68.96 ± 8.12 U/L) compared to the treated (66.09 ± 8.46 U/L) and reference (67.14 ± 7.96 U/L) groups.
  
  
  CONCLUSIONS
  The biochemical and radiologic results suggest that low-intensity pulsed ultrasound can be used as an auxiliary method to consolidate fractures and probably reduces the bone healing time, offering clinical benefits.
authors.affiliation: MSc, Discipline of Anatomy, Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Alameda Dr Octávio Pinheiro Brisola 9-75, Vila Nova Cidade Universitária, 17012-901 Bauru-SP, Brazil. kpuzipe@usp.br.
authors.forename: Karina T
authors.initials: KT
authors.lastname: Pomini
authors.forename: Jesus C
authors.initials: JC
authors.lastname: Andreo
authors.forename: Antonio de C
authors.initials: Ade C
authors.lastname: Rodrigues
authors.forename: Jéssica B
authors.initials: JB
authors.lastname: de O Gonçalves
authors.forename: Letícia R
authors.initials: LR
authors.lastname: Daré
authors.forename: Iris J S
authors.initials: IJ
authors.lastname: German
authors.forename: Geraldo M
authors.initials: GM
authors.lastname: Rosa
authors.forename: Rogerio L
authors.initials: RL
authors.lastname: Buchaim
mesh_terms: D000818:Animals; D001861:Bone Regeneration / Q000502:physiology* / Q000528:radiation effects*; D002113:Calcification, Physiologic / Q000187:drug effects; D004307:Dose-Response Relationship, Radiation; D017102:Fracture Healing / Q000528:radiation effects*; D050723:Fractures, Bone / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy*; D019220:High-Energy Shock Waves / Q000627:therapeutic use*; D008297:Male; D011829:Radiation Dosage; D011859:Radiography; D051381:Rats; D017208:Rats, Wistar; D016896:Treatment Outcome; D014464:Ultrasonic Therapy / Q000379:methods*
keywords: alkaline phosphatase; basic science; bone regeneration; fracture healing; radiography; ultrasound