Experimental Study On The Changes Of VEGF During The Treatment Of Docking Site Nonunion In Rabbits With Accordion Technique

Objective:To explore the changes of VEGF in the treatment of rabbit docking site nonunion model with accordion technique.Methods:A total of 25 healthy New Zealand white rabbit(6 months)were carried out the implementation of the left tibia osteotomy,high temperature burning,medullary cavity curettage,periosteum stripping and 2 mm of bone stump maintain with external fixation.8 weeks postoperative,perform the X-ray examine,and 1 rabbit were randomly selected to execute for histological examination.The remaining 24 rabbits were randomly divide into 2 groups:the blank control group(n=12),the accordion technique group(n=12)which received compression for 3 days at a rate of 1mm/d,follow by distraction for 3 days with the same rate,finally,repeat the first step.On the 7th,13 th,and 19 th days of the "accordion technique" operation,randomly 4 rabbits were execute in each group,and Immunohistochemical staining was used to detect the difference in the expression levels of VEGF.Results:1.X-rays at 8 weeks postoperative confirmed that the bone stump was consistent.Hematoxylin-eosin staining showed that the bone stump was covered with fibrous tissue.Thus the docking site nonunion model was successful.2.Immunohistochemical suggest cumulative optical density value of VEGF at three time points in accordion technique group were significantly higher than that in blank control group(P < 0.05).Conclusion:Docking site nonunion can be treated with accordion technique,the expression of VEGF can be stimulated in all stages of accordion technique.The VEGF may be one of the mechanisms of accordion technique to restart docking site union.