Late-stage Bone Callus Implant Combine With BMP-7 On Healing Bone Defect

PurposeTo observe the effects of late-stage bone callus implant combined with Bone Morphogenic Protein-7 (BMP-7) on fracture healing in rabbit fracture model, and to further discuss the effect of Vascular Endothelial Growth Factor (VEGF) on bone healing.MethodsBilateral mid-shaft radial fracture model was created on 20 Japanese rabbits, which were evenly divided into 2 study groups, and obvoius callus formation were observed after 12 weeks. Then the newly formed bone callus were excised and preserved for later usage. For Group I, the left radius (subgroup A) was treated with callus implant combined with BMP-7,and the Contralateral limb (subgroup B) was treated with iliac autograft. For Group 2, the left side (subgroup C) was treated with bone callus implant only, and the rigt side (subgroup D) was set as blank control. After 4 weeks, X-ray examination was performed to evaluate bone healing, and tissue samples were collected to measure the expression of VEGF mRNA.ResultsThere were no significant difference between subgroup A and B for VEGF expression. However, no obvious expression of VEGF were observed in subgroup C and D.ConclusionBone callus implant combined with BMP-7 may promote the expression of VEGF around the fracture site, thus facilitate the healing process.