Effects of pulsed electromagnetic field therapy at different frequencies and durations on rotator cuff tendon-to-bone healing in a rat model.


Author: Huegel J1, Choi DS1, Nuss CA1, Minnig MCC1, Tucker JJ1, Kuntz AF1, Waldorff EI2, Zhang N2, Ryaby JT2, Soslowsky LJ3

Affiliation: <sup>1</sup>McKay Orthopaedic Research Laboratory, University of Pennsylvania, Philadelphia, PA, USA.

<sup>2</sup>Department of Research and Clinical Affairs, Orthofix, Lewisville, TX, USA.

<sup>3</sup>McKay Orthopaedic Research Laboratory, University of Pennsylvania, Philadelphia, PA, USA. Electronic address: soslowsk@upenn.edu.
Conference/Journal: J Shoulder Elbow Surg.
Date published: 2017 Nov 22
Other:
  Pages: S1058-2746(17)30603-1   ,  Special Notes: doi: 10.1016/j.jse.2017.09.024. [Epub ahead of print]   ,  Word Count: 260  
    BACKGROUND: Rotator cuff tears affect millions of individuals each year, often requiring surgical intervention. However, repair failure remains common. We have previously shown that pulsed electromagnetic field (PEMF) therapy improved tendon-to-bone healing in a rat rotator cuff model. The purpose of this study was to determine the influence of both PEMF frequency and exposure time on rotator cuff healing.



METHODS: Two hundred ten Sprague-Dawley rats underwent acute bilateral supraspinatus injury and repair followed by either Physio-Stim PEMF or high-frequency PEMF therapy for 1, 3, or 6 hours daily. Control animals did not receive PEMF therapy. Mechanical and histologic properties were assessed at 4, 8, and 16 weeks.



RESULTS: Improvements in different mechanical properties at various endpoints were identified for all treatment modalities when compared with untreated animals, regardless of PEMF frequency or duration. Of note, 1 hour of Physio-Stim treatment showed significant improvements in tendon mechanical properties across all time points, including increases in both modulus and stiffness as early as 4 weeks. Collagen organization improved for several of the treatment groups compared with controls. In addition, improvements in type I collagen and fibronectin expression were identified with PEMF treatment. An important finding was that no adverse effects were identified in any mechanical or histologic property.



CONCLUSIONS: Overall, our results suggest that PEMF therapy has a positive effect on rat rotator cuff healing for each electromagnetic fundamental pulse frequency and treatment duration tested in this study.



Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.



KEYWORDS: PEMF; animal model; rat; rotator cuff; supraspinatus repair; tendon healing



PMID: 29174271  DOI: 10.1016/j.jse.2017.09.024