| Objectives To observe the radiographic manifestations and histological changes of the interface of bone graft in rabbits with spinal tuberculosis treated with nano-hydroxyapatite-calcium sulfate hemihydrate artificial bone loaded with isoniazid and rifampicino,and to evaluate the effect of the artificial bone composite in the local treatment of spinal tuberculosis.Methods Twenty-four spinal tuberculosis models of New Zealand white rabbits were successfully established at lumbar 4-5 segments with the standard strain of Myco-bacterium tuberculosis H37 Rv were randomly divided into two groups: A and B,12 rabbits in each group.Another 12 healthy New Zealand white rabbits were selected as blank control group C.The tuberculosis of lumbar 5 lesions was partially debridement in experimental group A and B,nano-hydroxyapatite-calcium sulfate hemihydrate artificial bone loaded with isoniazid and rifampicin was implanted in group A,and nano-hydroxyapatite-calcium sulfate hemihydrate artificial bone was implanted in group B.nano-hydroxyapatite-calcium sulfate hemihydrate artificial bone was implanted after partial vertebrae removal of the lumbar 5 in blank control group C.Four rabbits were randomly selected from three groups of rabbits at 4,8 and 12 weeks.CT scan and three-dimensional reconstruction were performed to observe the fusion of bone graft,then killled the rabbits,paraffin sections of the lesion vertebrae for HE staining?anti acid staining and trap staining study of histomorphology changes of nano-hydroxyapatite-calcium sulfate hemihydrate artificial bone loaded with INH and RFP in vivo,to observe whether there is Tuberculosis lesion,Mohan's nodule and the evolution of the lesion.Results 4w postoperation : The three groups of artificial bones materials were partially degraded and became smaller.The material-bone interface was blurred,bone bridge was formed,and there were some transparent areas.New capillaries,osteoblasts and bone trabeculae were formed,and fibrous junctions were formed at the interface of bone graft in group A and C.In group B,The material-bone boundary was clear,only a small amount of callus was formed,and the transparent areas were obvious,the sequester and inflammatory cells were seen at the interface of the material-bone,inactive proliferation of osteoblasts.8w postoperation: three groups of artificial bone materials were degraded obviously,the material-bone interface was closely combined and the intervertebral bone bridge was formed,proliferation of osteoblasts and the new bone were formed at the interface of bone graft in group A and C.The material-bone boundary was clear,the bone defect was further enlarged,the formation of intervertebral bone bridge was poor,the transparent area was obvious,inflammatory cells scattered among the trabeculae of bone,no fibroblast,necrosis,tuberculous nodule,aseous substances and inactive proliferation of osteoblasts were found in group B.12 w postoperation: three groups of artificial bone material were completely degraded.The artificial bone material was replaced by the bone tissue,intervertebral bone bridges were formed,pathological manifestations showed that the proliferation of osteocytes were active,the number of the lamellar bone and trabecula increased,the callus was formed and the bone fusion was good in group A and C.Bone defect was formed at the degradable material,the thin bone trabeculae,paravertebral cold abscess,caseous necrosis,local bone ischemia,sequester formation and the bone was not fused in group B.The Trap staining showed that :at 4w postoperation,a large amount of OC was formed in group A and group B.With the degradation of artificial bone materials,at 8w and 12 w postoperation,OC decreased significantly in group A compared with in group B(P < 0.05);the acid fast staining showed that: at 4w,8w and 12 w postoperation,the red acid fast bacilli were not found in group A,but the red thin rod acid fast bacilli were found in group B(P < 0.05).The trabecular bone areaanalysis of the material-bone interfacee in three groups showed that The area of bone trabecula in group A and group C was higher than that in group B at 8 and 12 weeks postoperation(P < 0.05).Conclusions 1?The nano-hydroxyapatite-calcium sulfate hemihydrate artificial bone loaded with isoniazid and rifampicino could play the role of local slow release antituberculosis treatment.2 ? During the degradation process of the nano-hydroxyapatite-calcium sulfate hemihydrate artificial bone loaded with isoniazid and rifampicino in the bone defect area,bone cells can crawl through the material space to replace and achieve bone interface fusion,which can play a good role in bone supporting ? bone repair and reconstruction in three months. |
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