Repair of Sheep Vertebra Defect with Nover Pedical Screw with BMP

Objective To explore features of novel lumbar pedicle screw with BMP in the repair of bone defects in sheep vertebral body.Methods Twelve adult sheep were used to construct bone defects models.All animals were divided into three groups.We compared the difference for the biomechanics of the maximum pullout strength,the stiffness modulus of immediately state after reconstruction and the ultimate compressive strength and observed tissue characters of lumbar spine by HE pathological staining method and test BMP-2mRNA expression by RT-PCR at the fourth and twelfth week in different groups.Results The maximum pullout strength was higher in novel than common(P0.05).There were difference about values of the ultimate compressive strength of immediately state after reconstruction.In novel group,the histological observation found there was difference between control group and novel group.The BMP-2mRNA expression in the first and fourth week and in outer and central space is higher in novel group than in control and common group,there is significant difference among them.Conclusion BMP-2 can strongly accelerate osteoclasts fissure and induce bone formation in outside bone,so the novel lumbar pedicle screw with BMP is very important for treating bone defect,it worth applying for clinical therapy.