Three Bio-bone Derived Materials To Repair Segmental Bone Defects In Rabbits

Purpose: To evaluate the efficacy of three kinds of biotic bone derived material in repairing segmental bone defect, and analyze the change of peripheral blood T lymphocyte subgroup CD4/CD8 ratio of rabbit in earlier period after transplantation of materials.Method: Three kinds of biotic bone derived material-Complicated Fully Deprotemised Bone (CFDB), Partially Deproteinised bone (PDPB), Partially Decalcified Bone (PDCB) were used to repair the 10mm segmental defect of the rabbits' radii, autogenous iliac bone and empty defect were used as control. Took specimens at 4, 8, 12 and 24 weeks after operation, radiographed and made undecalcified solid tissue slice. Flow cytometer was used to study the change of T lymphocyte subgroup of peripheral blood of the rabbits in earlier period after the biotic bone derived materials being implanted, fresh xenogeneic bone (FX) and empty defect were used as control.Result: 1.Radiograph:4 weeks, the border between the materials and host bone is distinct; 8 weeks, the border between the materials and host bone is vague; 12 weeks, the density of some part of the edge of the materials is similar to host bone; 24 weeks, medullary cavities of bone were formed in PDPB group, the density of defect area of the PDCB group is similar to radii ,the density of most parts of the defect area of the CFDB group is higher than the host bone. 2. Radiograph scoring: 4 weeks and 8 weeks, no significant difference is among 3 experimental groups (P>0.05); 12 weeks, PDPB group and PDCB group are higher than CFDB group (P<0.05); 24 weeks, PDPB group>PDCB group>CFDB group, (P<0.05). 3.Histomorphology observation: 4 weeks , callus grew into defect; 8 weeks ,new bone formed adhesive to the trabecula of materials; 12 weeks, more bone formation was seen; 24 weeks intramedullary canals were formed in PDPB group, tightly bone connections were formed in PDCB group, thin bone connections were formed in CFDB group. 4. Histomorphology analysis: 4 weeks and 8 weeks, the quantity of bone formation has no significant difference among 3 experimental groups (P>0.05); 12 weeks , the quantity of bone formation of PDPB group or PDCB group is higher than that of CFDB group(P<0.05); 24 weeks, quantity of bone formation: PDPB group>PDCB group>CFDB group(P<0.05). The peripheral blood T lymphocyte subgroup CD4/CD8 ratio of experimental groups have nosignificant difference with the empty contrast group(P>0.05), but has significant difference with FX group in all the stages. Conclusion:1. Three kinds of biotic bone derived material didn't cause serious immunologic rejection in earlier period after transplantation;2. PDPB has good efficacy in repairing the segmental bone defect, the efficacy of PDCB is inferior to it, the efficacy of CFDB is not ideal.