Application of compound bone morphogenetic protein 2,polylactide coglycolic acid and tricalcium phosphate in repair of large segmental defects in radius of sheep

Objective To study the application of compound bone morphogenetic protein 2（BMP-2）,polylactide coglycolic acid（PLGA） and tricalcium phosphate（TCP） in repair of large segmental defect in radius of sheepMethods A 30mm-long radius and ulna defect of sheep was established by surgery.Sheep were divided into group A and group B.Sheep in group A underwent implantation of compound BMP-2,PLGA and tricalcium phosphate into their radial defect.Sheep in group B received no implantation of any material into their radial defect.Radii in both groups were fixed with steel plates.Roentgenograms were taken 4,8,12 and 24 weeks after operation.The animals were killed 24 weeks after operation for histological examinationResults Roentgenogram revealed that the radial defect was completely healed 24 weeks after operation with a clear contour of cortical bone and medullary cavity in group A.No effective formation of callus was found in group B.Histological examination showed that the cortical bone was formed in the outer layer of callus as a rather mature lamellar bone,which was integrated with the broken ends of fractured bones with a large amount of residual bone marrow but without residual implanted material in group A 24 weeks after operation.However,a large amount of fibrous tissues were filled in the bone defect area of group BConclusion Compound BMP-2,PLGA and tricalcium phosphate can repair the large segmental defects of radius in sheep.