| Purpose:Investigating the effects of radius bone defects from 108 rabbits, repaired by a new biomaterials composed of a-hemihydrate calcium sulfate(a-CSH) and biphasic calcium phosphate(BCP), and comparing with a-CSH and BCP so as to supply theoretical theories to clinical applications and further studies of the new composite artificial bone material.Methods:In this study, we examined methods of fabrication of a-CSH and BCP, and a composite of the two materials. An unilateral radial segmental bone defect model was created in 108 New Zealand rabbits,36 each group. Each group separately implanted following materials: Group A:a-CSH/BCP composite artificial bone, Group B:a-CSH artificial bone, Group C:BCP artificial bone. Implant after 2,4,8,12 weeks for general observation, serum bone alkaline phosphatase testing, histological observation, X-ray examination, biomechanical testing and scanning electron microscope observation. The results were statistically analyzed using the SPSS version 21.00.Results:1, general observation:At 2 weeks after implantation, fibrous tissue and few callus grow around a-CSH/BCP artificial bone. At 4 weeks after implantation, a-CSH/BCP was wrapped with muscles, soft organizations and obvious callus. At 8 weeks after implantation, bone structures connected with a-CSH/BCP and the host bone. a-CSH/BCP artificial bone absorbed significantly compared with 4 weeks. At 12 weeks after implantation, a-CSH/BCP wrapped with new bone structures fundamental degraded, and bone defects were repaired.2, AKP testing:The differences was no significant between the three groups preoperative (P>0.05). At 2 weeks after implantation, the difference was no significant between a-CSH/BCP group and a-CSH group(P>0.05). At 4,8 weeks after implantation, the AKP values in a-CSH/BCP group were significantly higher than the other groups and there was statistically significant (P<0.05). At 12 weeks after implantation, the difference was no significant between a-CSH/BCP group and a-CSH group(P>0.05).3, histological observation:At 2 weeks after implantation, many osteogenic cell and few callus aggregated a-CSH/BCP artificial bone. At 4 weeks after implantation, trabecular and capillaries and fibroblasts could be observed around bone defects in a-CSH/BCP group. At 8 weeks after implantation, the quantity of the new bone increased gradually with the time prolonging, the center of the a-CSH/BCP artificial bone could be found new bone and the materials could be degraded gradually. a-CSH/BCP artificial bone most degra- dation, bone marrow cavity most recanalization. At 12 weeks after implantation, trabecular bone remodeling had been completed and no significant difference was found compared with the surrounding trabecular bone.4, X-ray examination:At 2 weeks after implantation, there were no significant difference among a-CSH/BCP group and a-CSH group. At 4 weeks after implantation, trabecular bone was blurred. At 8 weeks after implantation, continuity callus could been seen in a-CSH/BCP group, and marrow cavity partial recanalizated. At 12 weeks after implantation, good bone healing occurred in the a-CSH/BCP group. a-CSH/BCP artificial bone completely degradation, bone defect repair completely. Difference was statistically significant (P<0.05).5, biomechanical testing:The mechanical test showed that the maximum compression load in a-CSH/BCP group was significantly higher than the other groups in 12 weeks, but there were no significant difference compared with normal radius group.6, Scanning electron microscope observation:At 2 weeks after implantation, fibrous tissue and few callus grow around a-CSH/BCP artificial bone. At 4 weeks after implantation, a-CSH/BCP was wrapped with muscles, soft organizations and obvious callus. At 8 weeks, a-CSH/BCP artificial bone had gradually degraded, and new bone continual growing. At 12 weeks after implantation, a-CSH/BCP artificial bone had substantial degradated, and the amount of new bone formation was significantly higher than that of a-CSH and BCP group.Conclusion:This study demonstrated that a-CSH/BCP synthetic graft material was biocompatible, possesses osteoconductive properties, and can support new bone formation. The biodegradation of the material with time was also documented. Prove that the a-CSH/BCP composite artificial bone has a potential clinical value in the repair of long bone defects, provides a theoretical basis for clinical bone defect repair material selection, worth further studying. |
PDF Full Text Request