ABSTRACT
Objective To study the effects of uhrashortwave and low frequency pulsed electromagnetic fields on the expression of vascular endothelial growth factor(VEGF) in fracture healing. Methods Fifty-six New Zeal-and rabbits with artificial fractures were randomly divided into 4 groups:a control group,an ultrashortwave group,a low frequency pulsed electromagnetic field group and an ultrashortwave combined with low frequency pulsed electro-magnetic field group(combined group),with 14 in each group.Radiographic evaluation of callus formation and frac-ture healing,pathohistological examination and detection of VEGF expression through immunohistochemical staining were performed at the 1 st,2nd,4th and 6th week after the operation. Results Radiographic examination showed that there was significantly greater callus formation in the combined group than in the other groups throughout the healing process. Pathohistological examination also revealed significantly more cartilage islets and callus formation in the combined group.At the 1 st,2nd and 4th week after the operation,VEGF positive indexes in the combined group were significantly higher than in the other groups. Conclusion Uhrashortwave combined with low frequency pulsed electromagnetic field exposure can up-regulate the expression of VEGF and thus can accelerate fracture healing.