The Effect of Pulsed Electromagnetic Therapy on Femoral Bone Micro-Structure in Ovariectomized Rats

Background and Aim: Osteoporosis is a metabolic bone disease that can result from cytokines activity such as TNFɑ. The aim of this study was to evaluate the effect of pulsed electromagnet therapy on femoral strength and bone microstructure in ovariectomized rats. Materials and Methods: In this experimental study, 30 rats were randomly divided into control, experimental1 (ovariectomized) and two experimental groups; namely ovariectomized and undergoing pulsed electromagnet groups. The control and experimental1 groups were kept under controlled conditions, while the two experimental groups were treated with pulsed electromagnet (2.4 mT) from 12 postoperative weeks for 30min, 3days a week, for 10 weeks. Then, the subjects were sacrificed and their femoral bones were removed to determine the strength and the bone microstructure parameters (the trabecular and cortical thicknesses and trabecular distances). In order to determine bone microstructures, the sections were prepared and stained with HE Chicago, IL). Results: Despite equal initial weight of the subjects (P=0.15), they significantly gained weight after12 and also 22 postoperative weeks (P<0.001). Cortical and trabecular thicknesses, and femoral strength respectively and significantly decreased in the experimental group 1 .X=220.80±5.90, P<0.001; X=90.34±5.73,P=0.001; X=5.15±1.07,P=0.002. In the experiment. group 2, decrease was .X=255.40±6.02,P<0.001; X=113.50±3.43, P=0.008; X=8.00±1.11,P=0.015; respectively, comparing with the control group (X=232.36±5.13, X=100.50±5.06, X=6.95±1.16). Cortical and trabecular thicknesses, and bone strength significantly increased in the experimental group 2, compared to the experimental group 1(P<0.001). There was also a significant decrease in the trabecular distance in the experimental group 2 (X=111.60±2.87) compared to the experimental 1 (X=127.40±4.74, P<0.001).