title: Preliminary studies of duration and intensity of ultrasonic treatments on fracture repair.
abstract: Bone formation of fractured fibulae stimulated by ultrasound was evaluated with roentgenography and fluorochromes labelling. The fibulae of male New Zealand rabbits were fractured to create a 3 mm-gap. Ultrasounds at 0.5 or 1.0 W/cm2 were applied for various durations, 5, 15, and 25 min/day for 4 weeks. Ultrasonic treatments at 0.5 W/cm2, 1.5 MHz significantly accelerated bone formation at the fracture site for all durations, whereas the higher intensity at 1.0 W/cm2 suppressed the bone formation of the treated fractured fibula. Ultrasounds at 0.5 W/cm2 were stimulatory to fracture repair, if given for 15 min/day, and were recommended for future clinical trials. However, ultrasounds at the intensity of 1.0 W/cm2 were deleterious to the treated fracture and not recommended for clinical trials.
authors.affiliation: Department of Orthopaedic Surgery, National Taiwan University, Taipei, Republic of China.
authors.forename: C L
authors.initials: CL
authors.lastname: Tsai
authors.forename: W H
authors.initials: WH
authors.lastname: Chang
authors.forename: T K
authors.initials: TK
authors.lastname: Liu
mesh_terms: D000818:Animals; D050723:Fractures, Bone / Q000628:therapy*; D011817:Rabbits; D013997:Time Factors; D014464:Ultrasonic Therapy; D014945:Wound Healing / Q000502:physiology