Repair with decalcified bone matrix, bone cement and bone morphogenetic protein for canine femoral defect caused by microwave-induced hyperthermia

摘要

In order to investigate the effects of the repair with decalcified bone matrix (DBM) and bone cement (BC) combined with bovine bone morphogenitic protein (bBMP) for the femoral defect caused by microwave-induced hyperthermia and to definite the biological procedure of this composite material in dogs.Methods: The DBM of dogs was prepared beforehand. The bBMP was extracted and its bone formation inductive activity was determined. The structural feature of the composite material was observed by scan electron microscope (SEM) and the biomechanical properties of that were assessed. Then the canine femoral defect was caused by microwave-induced hyperthermia and the composite material was transplanted in. The canine femurs were examined by X-ray,99mTc-MDP bone scintigraphy, histological section and biomechanics at different postoperative time.Results: The bBMP extracted by ourselves had strong bone formation inductive activity and the composite material had excellent biological property. The DBM was connected with BC tightly by multipolar mode and irregular gaps with diameter of 200 μm to 800 μm were existed. The callus was found at the 1st month and its amount was most abundant at the 3rd month by X-ray examination. The new blood vessels and new bones were formed in the composite material and that were confirmed by 99mTc-MDP bone scintigraphy and histological sections. The new bone in the edge was connected with the normal bone. While the biomechanical strength of the experimental femurs had reached 60% and 80% of the normal femurs at the 3rd month and the 6th month respectively. Conclusions: The composite material could be remodeled easily and the new blood vessels could growth into because there were a large amount of irregular gaps in it. New bone could be formed by the induction of BMP and the DBM could be replaced by the new bone. So the composite material could be merged with the normal bone.