Effect Of Artificial Bone With Different Size On Repairing Lacunary Bone Defect

BackgroundBone transplantation is an important way to repair the bone defect. At present, there are three types of bone graft in clinic, which include autograft of bone, allograft of bone and artifical bone graft. As a substitute of bone, the artificial bone is easily harvested and processed, as well as posses a good biocompatibility. The bioceramic is used to the area of orthopaedic, and has presented better results in treating lacunar bone defect. However, the usage ofβ-TCP still exist the quantifying shortage. Usually the surgeon applied the"press-fit"method to fill the bone defect. However, the rationality and validity of the method was not certified in study. The implanted methods of the artificial bone directly influenced the repair and reconstruction of lacunar bone defects. The study has proved that the appropriate interspace of particles is suitable for new bone growing and artificial bone resorption. Meanwhile, the dynamic balance between degradation of artificial bone and new bone formation also affect bone remodeling in the implanted area. Either excessive or less artificial bone graft can influence the process of material degradation and new bone formation. This study compared the effect of the differentβ-TCP particle size on repairing lacunar bone defect. We hoped to search the scientific evidence ofβ-TCP standard usage and to provide experimental support for surgeon.ObjectiveTo investgate the effect of different particle size ofβ-TCP on treating lacunar bone defect.MethodsThere were four groups in this experiment: Group A: Large granular group (diameter 3.5-4.5mm); Group B: small granular group (diameter 1.5-2.5mm); Group C: en bloc group (a cylinder bone block with diameter 6mm, height 8mm); Group D: blank control group. The materials were filled randomly in the lacunar defects (diameter 7mm, height 6mm) which had been maded in both proximal tibias. Twenty rabbits (5 in each group) were sacrificed at 2, 4 and 8 weeks postoperatively. The new bone formation and theβ-TCP degradation were detected by X-rays, Micro-CT and histology.ResultsThe analysis of radiology and histology revealed that the new bone formation and the degradative rate of theβ-TCP in large granular group were better than other groups. Biomechanical test showed that the max failure stress in large granular group was lower than one in en bloc group at 2 weeks. But at 4 and 8 weeks, the max failure stress became higher in large granular group than one in other groups.ConclusionThe diameter of particles might influence reparing and remodeling of lacunar bone defect. The pack of large granularβ-TCP showed better osteoconduction and more favourable material degradation.