title: [Effect of low-intensity pulsed ultrasound stimulation on maturation of regenerate bone].
abstract: OBJECTIVE
  To explore the effect of low intensity pulsed ultrasound stimulation (LIPUS) on the maturation of regenerate bone in a rabbit limb lengthening model.
  
  
  METHODS
  Sixty skeletal mature female New Zealand white rabbits were randomly divided into an LIPUS treatment group and a control group. All rabbits were underwent mid-diaphyseal tibial osteotomy and immobilized in an Orthofix M103 Mini lengther. Gradual distraction at 0.5 mm every 12 h for 10 d was performed at day 7 postoperatively. A 4-week course of LIPUS treatment group was applied over the distraction site for 20 min daily starting immediately after the completion of the distraction only for the treatment group. Rabbits were euthanized and the mid-diaphyseal tibia was harvested for evaluation at 4, 8, and 12 wk after the completion of the bone lengthening protocol. Radiographic analysis was performed to study the formation of bone callus using the ImageJ software at 12 wk after the completion of the bone lengthening protocol. Bone mineral density (BMD) of regenerate bone was measured by Dual energy X-ray absorptiometry (DEXA). Torsional testing to failure was performed on the tibia specimens at 8 and 12 wk after the completion of the bone lengthening protocol.
  
  
  RESULTS
  Radiographic measurement showed higher relative gray scale of bone callus in the LIPUS group than that in the control group at 12 wk (P<0.05). BMD in the LIPUS group was significantly higher than that in control group at 8 and 12 wk (P<0.05). Biomechanical testing showed that the ultimate torque, ultimate torsional stiffness, and energy absorption at failure of regenerated bone at 8 and 12 wk in the LIPUS treatment group were better than those in the control group (P<0.05).
  
  
  CONCLUSIONS
  LIPUS as a biophysical stimulation may accelerate the formation and maturation of regenerate bone in rabbit tibia lengthening model.
authors.affiliation: Department of Sports Medicine, Xiangya Hospital, Research Center of Sports Medicine, Central South University, Changsha, China. hongbinlu@hotmail.com
authors.forename: Hongbin
authors.initials: H
authors.lastname: Lü
authors.forename: Ying
authors.initials: Y
authors.lastname: Yang
authors.forename: Chi
authors.initials: C
authors.lastname: Zeng
authors.forename: Jiahui
authors.initials: J
authors.lastname: Zhou
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Hu
authors.forename: Daqi
authors.initials: D
authors.lastname: Xu
authors.forename: Kanghua
authors.initials: K
authors.lastname: Li
authors.forename: Ling
authors.initials: L
authors.lastname: Qin
mesh_terms: D000818:Animals; D001861:Bone Regeneration / Q000528:radiation effects*; D002146:Bony Callus / Q000528:radiation effects*; D005260:Female; D010012:Osteogenesis / Q000528:radiation effects; D019857:Osteogenesis, Distraction; D010027:Osteotomy; D011817:Rabbits; D011859:Radiography; D011897:Random Allocation; D013978:Tibial Fractures / Q000000981:diagnostic imaging / Q000628:therapy*; D014464:Ultrasonic Therapy / Q000379:methods*