Histological evaluation of the influence of magnetic field application in autogenous bone grafts in rats

Abstract

BackgroundBone grafts are widely used in oral and maxillofacial reconstruction. The influence of electromagnetic fields and magnets on the endogenous stimulation of target tissues has been investigated. This work aimed to assess the quality of bone healing in surgical cavities filled with autogenous bone grafts, under the influence of a permanent magnetic field produced by in vivo buried devices.MethodsMetal devices consisting of commercially pure martensitic stainless steel washers and titanium screws were employed. Thirty male Wistar rats were divided into 3 experimental and 3 control groups. A surgical bone cavity was produced on the right femur, and a bone graft was collected and placed in each hole. Two metallic washers, magnetized in the experimental group but not in the control group, were attached on the borders of the cavity.ResultsThe animals were sacrificed on postoperative days 15, 45 and 60. The histological analysis of control and experimental samples showed adequate integration of the bone grafts, with intense bone neoformation. On days 45 and 60, a continued influence of the magnetic field on the surgical cavity and on the bone graft was observed in samples from the experimental group.ConclusionThe results showed intense bone neoformation in the experimental group as compared to control animals. The intense extra-cortical bone neoformation observed suggests that the osteoconductor condition of the graft may be more susceptible to stimulation, when submitted to a magnetic field.

Regulation of osteoclast differentiation by static magnetic fields

“…SMF has been studied as a noninvasive physical treatment for promoting bone growth and bone healing, and preventing bone loss (Zhang et al, 2014a). Animal studies have revealed that certain SMFs have a synergistic role in such circumstances as bone surgical invasion (~50 mT) (Yan et al, 1998), ischemic bones (~50 mT) (Xu et al, 2001), ovariectomized rats (180 mT) (Xu et al, 2011), adjuvant arthritis rats (30-80 mT) (Taniguchi et al, 2004), bone fracture (4 mT) (Puricelli et al, 2006) and bone grafts (4 mT) (Puricelli et al, 2009). Most cellular studies indicate that the anabolic effects on bone homeostasis are due to the enhanced activities of osteoblast and promoted osteogenic differentiation in mesenchymal stem cells, although the underlying mechanisms of SMF effects on cell activities are still unclear (Colbert et al, 2009;Markov, 2007).…”

Magnetically induced electrostimulation of human osteoblasts results in enhanced cell viability and osteogenic differentiation

“…It has also been shown in vitro and in vivo , that biophysical stimulation via the application of electric currents enhances bone healing and restores structural strength ( 13 – 15 ). Based on these findings, electrical bone growth stimulators have been developed for clinical application ( 16 , 17 ).…”

Pentoxifylline and electromagnetic field improved bone fracture healing in rats

“…For many years, EMFs have been researched as a stimulation method to enhance bone regeneration in maxillofacial surgery, including dental implants, distraction osteogenesis, and bone grafts. 21 , 38 , 39 The knowledge from recent studies 40 , 41 has conclusively demonstrated that the contribution of EMFs to the bone healing process is based on stimulating the expression of growth factors, such as vascular endothelial growth factor and bone morphogenetic protein. EMFs also induce angiogenesis, migration, proliferation, and differentiation of stem cells from the surrounding mesenchymal tissues into cartilage and bone-forming cells in an area of injury.…”