title: 12. Influence of Wound Dressing on the Fracture Healing Effect of Low-Intensity Pulsed Ultrasound (LIPUS).
abstract: OBJECTIVE
  We have conducted a basic study on the influences on ultrasonic properties when LIPUS is applied through wound dressing. According to the results of ex vivo experiments conducted to date, LIPUS showed ultrasonic properties such as transmittance, coefficient of transmission, and a non-uniformity ratio through film wound dressing better than other wound dressing, and it was considered that LIPUS's effect for fracture healing was not influenced by film wound dressing. Then, we discussed the influence on the effect of LIPUS through film wound dressing.
  
  
  METHODS
  Thirty male 8-week-old Sprague-Dawley rats were used for the trial. After creating close transverse femoral fractures on the right legs of these 30 rats, they were divided into 3 groups of 10; LIPUS through wound dressing (Group A), LIPUS without wound dressing (Group B), and No LIPUS treatment (Group C). OPSITE Wound, which was thought to have the least influence on ultrasound properties, was used for this trial. Group A and B received LIPUS for 20 minutes a day from the first day after the fractures. LIPUS was generated from Teijin Pharma's device for a basic experiment. When treating Group A, the wound dressing was pasted on the ultrasound terminal in order to apply LIPUS through the dressing. We assessed the time-oriented morphological change of each group in anesthetized condition using simple radiographs on the 8th, 16th, and 24th day after the fractures.
  
  
  RESULTS
  Six rats in Group A, 2 in Group B, and 1 in Group C died in anesthesia, and we discussed the remaining 4 rats in Group A, 8 in Group B, and 9 in Group C. We defined more than one teleost callus bridging as bone-union. We also counted a bone remodeling when we recognized the absorption of existing cortical bone and the transformation of new bone to cortical bone in simple radiographs. As a result, compared with Group C, we recognized that both bone union and remodeling accelerated remarkably in Group B, but not in Group A.
  
  
  CONCLUSIONS
  It suggested that LIPUS through wound dressing had negative influences on both period shorting of fracture healing and bone remodeling. When LIPUS was conducted through film wound dressing, transmittance and coefficient of transmission were unchanged; however, the non-uniformity ratio changed slightly. The non-uniformity ratio of the ultrasound transducer had a significant influence on the effect of LIPUS on fracture healing.
authors.affiliation: *Department of Orthopaedic Surgery, Kitasato University Medical Center; †Department of Orthopaedic Surgery, Kitasato University School of Medicine; and ‡Hakutokai Takao Hospital.
authors.forename: Koji
authors.initials: K
authors.lastname: Naruse
authors.forename: Masataka
authors.initials: M
authors.lastname: Uchino
authors.forename: Noriko
authors.initials: N
authors.lastname: Hirakawa
authors.forename: Masahiro
authors.initials: M
authors.lastname: Toyama
authors.forename: Genyo
authors.initials: G
authors.lastname: Miyajima
authors.forename: Manabu
authors.initials: M
authors.lastname: Mukai
authors.forename: Ken
authors.initials: K
authors.lastname: Urabe
authors.forename: Kentaro
authors.initials: K
authors.lastname: Uchida
authors.forename: Moritoshi
authors.initials: M
authors.lastname: Itoman