title: Pulsed electromagnetic field treatments enhance the healing of fibular osteotomies.
abstract: This study tested the hypothesis that pulsed electromagnetic field (PEMF) treatments augment and accelerate the healing of bone trauma. It utilized micro-computed tomography imaging of live rats that had received bilateral 0.2 mm fibular osteotomies (approximately 0.5% acute bone loss) as a means to assess the in vivo rate dynamics of hard callus formation and overall callus volume. Starting 5 days post-surgery, osteotomized right hind limbs were exposed 3 h daily to Physio-Stim PEMF, 7 days a week for up to 5 weeks of treatment. The contralateral hind limbs served as sham-treated, within-animal internal controls. Although both PEMF- and sham-treatment groups exhibited similar onset of hard callus at approximately 9 days after surgery, a 2-fold faster rate of hard callus formation was observed thereafter in PEMF-treated limbs, yielding a 2-fold increase in callus volume by 13-20 days after surgery. The quantity of the new woven bone tissue within the osteotomy sites was significantly better in PEMF-treated versus sham-treated fibulae as assessed via hard tissue histology. The apparent modulus of each callus was assessed via a cantilever bend test and indicated a 2-fold increase in callus stiffness in the PEMF-treated over sham-treated fibulae. PEMF-treated fibulae exhibited an apparent modulus at the end of 5-weeks that was approximately 80% that of unoperated fibulae. Overall, these data indicate that Physio-Stim PEMF treatment improved osteotomy repair. These beneficial effects on bone healing were not observed when a different PEMF waveform, Osteo-Stim, was used. This latter observation demonstrates the specificity in the relationship between waveform characteristics and biological outcomes.
authors.affiliation: Department of Biomedical Engineering, The Orthopaedic Research Center, Lerner Research Institute of The Cleveland Clinic Foundation, Cleveland, OH 44195, USA. midura@bme.ri.ccf.org
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Midura
authors.forename: Michael O
authors.initials: MO
authors.lastname: Ibiwoye
authors.forename: Kimerly A
authors.initials: KA
authors.lastname: Powell
authors.forename: Yoshitada
authors.initials: Y
authors.lastname: Sakai
authors.forename: Todd
authors.initials: T
authors.lastname: Doehring
authors.forename: Mark D
authors.initials: MD
authors.lastname: Grabiner
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Patterson
authors.forename: Maciej
authors.initials: M
authors.lastname: Zborowski
authors.forename: Alan
authors.initials: A
authors.lastname: Wolfman
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002146:Bony Callus / Q000473:pathology; D004574:Electromagnetic Fields; D005360:Fibula / Q000293:injuries* / Q000473:pathology / Q000502:physiology; D017102:Fracture Healing / Q000528:radiation effects*; D008297:Male; D010027:Osteotomy; D051381:Rats; D017207:Rats, Sprague-Dawley