Alphonsus Chong's Personal Wiki

OBJECTIVE: Magnets are purported to aid wound healing despite a paucity of scientific evidence. The purpose of this study was to evaluate the effect of static magnetic fields on cutaneous wound healing in an animal model. The literature was reviewed to explore the historical and scientific basis of magnet therapy and to define its current role in the evidence-based practice of plastic surgery.

METHODS: Standardized wounds were created on the backs of 33 Sprague-Dawley rats, which were divided into 3 groups with either a 23 gauss magnet (group 1), a sham magnet (group 2), or nothing (group 3) positioned over the wound. The rate of wound closure by secondary intention was compared between the groups. Literature review was conducted through searches of PubMed and Ovid databases for articles pertinent to magnets and wound healing.

RESULTS: Wounds in the magnet group healed in an average of 15.3 days, significantly faster than those in either the sham group (20.9 days, P = .006) or control group (20.3 days, P < .0001). There was no statistically significant difference between the sham and control groups (P = .45).

CONCLUSIONS: An externally applied, low-power, static magnetic field increases the rate of secondary healing. Review of the literature reveals conflicting evidence regarding the use of magnetic energy to aid the healing of bone, tendon, and skin. Level I studies are lacking and difficult to execute but are needed to define conclusively the role of magnets in clinical practice.

• model of secondary intention healing in rats
  • how was size standardized?
• Protocol
  • Magnet applied 24×7 in this study vs pulsed
  • strength 23 gauss weak vs 400 etc …
• blinding?
• Evidence for bone by Fukuda and Yasuda
• Amphibian limb regeneration
• Mechanisms
  • vascular
• Magnetic vs electromagnetic?
• Other studies
  • Leaper: 400 gauss - no effect on wound healing, collagen content or tensile strength
  • Patino: 200 gauss - faster healing in wounds with intermittent EMF fields
  • Callaghan: similar to Patino
  • Strauch: accelerated healing and higher tensile strength in rat wounds exposed to PEMF
• Tendons even less clear

The data regarding magnet therapy for tendon healing are even more ambiguous. Greenbough applied pulsed electromagnetic fields to repaired flexor tendons in rabbits and found no benefit in terms of tensile strength or adhesion formation,37 whereas Robotti et al showed that pulsed electromagnetic fields decrease tensile strength and increase adhesions after tendon repair in chickens.38 These studies are in stark contrast to that of Strauch et al who recently demonstrated a 69% increase in tensile strength in repaired Achilles tendons in rats. They emphasized the importance of using a pulsed magnetic field of low amplitude (0.1 gauss) designed to maximize the effect on calcium ions, which, in theory, enhances the calcium-dependent activation of growth factors.39

Henry, S. L., Concannon, M. J., & Yee, G. J. (2008). The effect of magnetic fields on wound healing: Experimental study and review of the literature. Eplasty, 8, e40.

• Created: 2021-05-15