OBJECTIVETo study the effect of vascular endothelial growth factor (VEGF)and anti-VEGF on the expression of fracture healing-related factors and observe pathological changes at fractured sites.

METHODSFracture models were established in 105 New Zealand white rabbits and they were randomly divided into control group, VEGF group and anti-VEGF group. The relevant factors expression at fractured sites was assayed and pathological changes were observed in decalcified samples at 8, 24, 72 hours and 1,3,5,8 weeks after fracture.

RESULTSAfter application of VEGF, the expression of BMP appeared earlier and expression time lasted longer. On the contrary, anti-VEGF completely inhibited the expression of BMP. The fractured sites were filled with fibrous callus, cartilaginous callus and bony callus at the 3rd week and woven bone was constructed at the 5th week. Fracture healing was accomplished at the 8th week in VEGF group. In anti-VEGF polyclonal antibody group, cellular necrosis increased at early period. Continuous focal necrosis was seen in the fractured sites from the 1st week to 5th week. Vascularization reduced obviously at the 3rd week.

CONCLUSIONSFracture healing is a result of mutual regulation and coordination among many factors. VEGF may be an important factor in fracture healing.