| Objective: To study the effects of ultrashortwave and pulsed electromagnetic field on expression of vascular endothelial growth factor(VEGF) in fracture healing. And It also provides the academic foundation for clinical treatment and early rehabilitation.Methods: Fifty-six New Zealand rabbits were randomly divided into 4 groups: the contral group (n=14), ultrashortwave group(n=14), pulsed electromagnetic fields group (n=14) and ultrashortwave pulsed electromagnetic field group (combination group) (n=14). We made the complete transection radius fracture model according to the references. The ultrashortwave group were gave the ultrashortwave treatment which the wave is 7.3m after 48h of operation. The interspace is 2-3cm. And the dosage is 50mA. The pulsed electromagnetic field group were gave the pulsed electromagnetic treatment which the frequency is 50Hz and the intensity is 0.5T after 48h of operation. The ultrashortwave pulsed electromagnetic field group (combination group) were gave the ultrashortwave treatment and plused electromagnetic treatment after 48h of operation. The method is same as above. The treatment course of each group was 21days. Radiographic evaluation of callus formation, histologic examination and micrsopical detection of VEGF expressions with immunohistochemical staining was performed at the 1st, 2nd , 4rd and 6rd week after operation. Results: 1.The radiographic examination showed that there were statistically significant amount of callus formation in ultrashortwave group, pulsed electromagnetic fields group and ultrashortwave pulsed electromagnetic field group (combination group) compared to the control group at the same time point. (P<0. 05) Meanwhile it also showed that there were statistically significant amount of callus formation in combination group compared to the ultrashortwave group, pulsed electromagnetic fields group at the same time point. (P<0.05)2. . In histologic examination, there were more significant cartilage bones and callus formation in ultrashortwave pulsed electromagnetic field group compared with the other groups.3. The immunhistochemical examinations showed VEGF positive indexes in ultrashortwave pulsed electromagnetic field group were significantly higher than the other groups (P<0. 05) .And the expression of VEGF was time dependent. The result of factorial showed that ultrashortwave and electromagnetic field have the synergistic effect (P<0. 01).Conclusions: 1.The expression of VEGF was time dependent.2. Ultrashortwave and pulsed electromagnetic field can up-regulate expressions of VEGF so that they can accelerate the healing process of bone fracture.3. Ultrashortwave plus pulsed electromagnetic field have the synergistic effect, so to use them together can more accelerate the healing process of bone fracture... |
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