[Effects of bone morphogenetic protein and transforming growth fractor-beta on biomechanical property for fracture healing in rabbit ulna].

OBJECTIVE: To investigate the effects of exogenous bone morphogenetic protein (BMP) and transforming growth factor-beta (TGF-beta) on biomechanical property for ulna of fracture healing. METHODS: Thirty-six adult rabbits were made the model of right ulnar fracture and treated locally with TGF-beta/PLA, BMP/PLA, TGF-beta + BMP/PLA or PLA (as control group). Fracture healing was evaluated by measurement of the mechanical parameters and geometric parameters. RESULTS: As compared with control group, the geometric parameters, the bending broken load, the ultimate bending strength, the bending elastic modulus, the ultimate flexural strength, the flexural elastic modulus, the ultimate compressing strength, the compressing elastic modulus, and the ultimate tensile strength for ulna of fracture healing increased significantly in the treatment groups(P < 0.01). These parameters were higher in TGF-beta + BMP/PLA group than in TGF-beta/PLA group or in BMP/PLA group and in TGF-beta/PLA group than in BMP/PLA group(P < 0.05). There was no significant difference in bone density between the treatment groups and control group. CONCLUSION: Local application of exogenous TGF-beta and BMP can increase the callus formation and enhance biomechanical strength of bone after fracture healing. A combination of TGF-beta and BMP has synergetic effect in enhancing fracture healing.