The effects of exogenous bone morphogenetic protein and transforming growth factor-beta on repairing ulna defects in rabbits

Objective To investigate the effects of exogenous bone morphogenetic protein (BMP) and transforming growth factor beta (TGF-β) on repairing bone defects Methods Adult rabbits were inflicted with the model of 1 5 cm segmental defect in the right ulna and treated locally with TGF-β and BMP,alone or in combination in the bone defect site.The repair capability was evaluated by gross,histological and radiographic examinations at the 4th,8th and 12th week and by biomechanical tests at the 12th week after operation.Results The bone defects were all repaired in the treatment groups,which could not be found in the control group.The repair was better in co treatment group with TGF-β and BMP than in treatment groups with TGF-β or BMP alone respectively,whereas BMP group was better than TGF-β group.The biomechanical strength of the ulna in the co treatment group with BMP and TGF-β was approached to that of normal bone,whereas that of treatment alone with BMP or TGF-β was weaker than normal bone and TGF-β group was weaker than BMP group.Conclusion BMP and TGF-β could promote repair of segmental bone defects and the effect of BMP is better than that of TGF-β.It has been observed co treatment with BMP and TGF-β can enhance further this effect and their interact with each other to modulate cooperatively and synergistically repairing bone defects.