The effect of bone membrane on secretion of BMP-2 and bone healing in a rabbit model of bone defect

Abstract

Objective To investigate the effect of bone membrane on secretion of bone morphogenetic protein-2(BMP-2) and bone healing in a rabbit model of bone defect.Methods Forty-eight New Zealand rabbits (4 months old,half male and half female) were randomly divided into 2 equal groups (n =24).A 0.5 cm bone defect of middle radius was created operatively under anesthesia in all the animals.The bone membrane around the defect was preserved in group A but exsected in group B.Six rabbits in each group were sacrificed each time at immediate,1,3 and 4 weeks post-operation.X-ray films of the bone defects were taken,gross observation of the tissue samples from the defect site was made,and semiquantitative detection of BMP-2 content by Western blotting was conducted at each time point.Quantitative assessment of bone healing was performed using Lane-Sandhu X-ray evaluation system.Results In group A,the amount of BMP-2 increased gradually at l,3,4 weeks postoperation,significantly higher than that at immediate postoperation (P ＜ 0.05).In group B,the amount of BMP-2 peaked at one week postoperation,significantly higher than that at immediate postoperation (P ＜ 0.05).At one week postoperation,there was no significant difference between the 2 groups in the amount of BMP-2 (P ＞ 0.05).At 3 and 4 weeks postoperation,the amount of BMP-2 in group A was significantly higher than in group B (P ＜ 0.05) and the mean Lane-Sandhu X-ray score in group A was also significantly higher than in group B (P ＜ 0.05).Conclusion Since preservation of bone membrane increases secretion of BMP-2 and promotes bone healing in the healing process of bone defect,we should try to preserve bone membrane when bone defects are treated. Key words: Bone morphogenetic proteins; Bone membrane; Bone healing; Bone defect