| Objective: To fill the bone defect with the new type of calcium phosphate cement (BiopexR) and it compounded self-blood, through animal experimental observe for longer time. we can more assure living creature characteristic of the BiopexR, and at the same time we can find a better way to promote the course of the creeping and displacement. Materials and Methods 1. Materials (1) The calcium phosphate cement of the new type, i.e. BiopexR, was co-developed by the first Hospital of Jilin University, Aichi Medical University in Japan and the Ceramics Research Institute for Material Development of the Mitsubishi Corporation. BiopexR, manufactured by the Mitsubishi Corporation, consists of powder and solidification liquid. The former contains α-tricalcium phosphate (α-TCP), tetracalcium phosphate (TeCP), dicalcium dihydrate (DCPD), hydroxyapatite (HAP) and magnesium phosphate [Mg3(PO4)2], while the latter is comprised of sodium chondroitin sulfate, sodium succinate, sodium bisulfite and water for injection. The ratio of powder to liquid is 3:1, or the ratio of powder to liquid to self-blood is 6: 1: 1. (2) Instrumentation:Trepan (Φ=3.5mm) manufactured by the Mitsubishi Corporation. (3) Animals in the experiment and grouping: We selected 36 healthy and mature Chinese rabbits, which were 4 to 6 months old and averaged 5 months. Their weight ranged from 2.0 to 3.0 kg, and the average weight was 2.5kg. We divided the rabbits into 2 groups randomly, i.e. the BiopexR-filling group, the BiopexR compounded self-blood group. Based on the post-operative observation time, each group was subdivided into 4 subgroups: 3 week, 6 weeks, 12 weeks and 24 weeks. 2. Method First, we made the rabbit model, in which the cement (BiopexR) or the BiopexR compounded self-blood was filled into the bone defect in the femur condyle. Then the animal specimens were observed through the body, the radiograph, the histomorphology and the transmission electron microscope (TEM). the results of the BiopexR-filling group and the BiopexR compounded self-blood group were compared at the same condition. so that we could study the biocompatibility and osteogenesis of BiopexR and the affect of creeping and displacement after joining self-blood into BiopexR Result 1. Body observation: Except for a rabitt being dead because of infection, a rabbit being the femal fracture and BiopexR injecting into knee articular cavity, the others were all right. They were found no obvious abnormity. In CPC group, in the 3rd week there was no obvious phenomenon of new bone formation, the brim of bone was very clear. In the 6th week, the brim of the bone became vague and there was a little new bone formation around CPC. In the 12th week,we could see middle many new bone formation, the density of CPC in the specimen is less than the two earlier groups of the specimens. In the 24th week, there were many new bone formation, the density of CPC was lest. Moreover in self-blood group, in the 3rd week there was no obvious phenomenon of new bone formation, the brim of bone was clear. In the 6th week, the brim of the bone became vague and there was new bone formation around it. In the 12th week, we could see many new bone formation, the density of CPC in the specimens were decreased, compared to the same period of specimens, the density of CPC was less. In the 24th week, there were a lot of new bone formation, it had creeped into bone tunnel. 2. Radiograph observation: In the 3rd week after the operation, the image of the transplanted CPC was distinct in the BiopexR-filling group, and so was the brim between CPC and host bone. In the 6th week, the image of CPC was still clear, but the brim became vague. In the 12th week, the density of CPC began to degradation, dwindled in size, but it had more than the same period of the self-blood specimens, CPC near to host bone was absorbed, the brim was a little vague. In the 24th week, CPC became farther degradative. The brim between CPC and host bone was more broadened. In the self-blood group, the image of the transplanted CPC was distinct, CPC was not decreased, but the brim between CPC and host bone became little vague. In the 6th week, the density of CPC began to degradation, the brim was clearly vague. In the 12th week, the density of CPC was more degradated, clearly dwindled in size, thebrim was farther vague. In the 24th week, CPC became most degradative. The brim between CPC and host bone was most broadened. The volume of CPC was smallest. The image of CPC and new-born bone even were interlaced. 3. Histomorphology observation: There was no avascular necrosis of bone or cartilage in every group. In BiopexR-filling group: In the 3rd week, CPC did not decrease evidently, new-born bone formed on the surface of CPC. But there was a little bone matrix and many infantile osteocytes which filled the trabecula of the bone with could be found. no space or fibrous layer existed between the CPC and the host bone. They were integrated directly. In the 6th week, the amount of CPC only little decreased. the trabecula of the new bone could be seen on the surface of CPC. CPC and the new-born bone were interlaced. There was no fibre between them and they directly formed concrescence. In the 12th week CPC clearly decreased, the trabecula of the new bone augmented. The material and new bone interlaced together so as to form webs. In the 24th week, the amount of CPC farther decreased, mature osteocytes could be seen. Mature bone casing plys were found. In the self-blood group, in the 3rd week CPC degradation was alike CPC group, but there were more bone matrix and less infantile osteocytes than CPC group. In the 6th week, the amount of CPC dwindled. The surface of CPC became sparse. There were many new-born bones having creeped into CPC, which departed CPC into many regions as so to seem islands. At the same time, a new-born little blood vessel was found. In the 12th week, theamount of CPC farther dwindled, mature osteocytes appeared. Mature casing plys were found. In the 24th week, the amount of CPC was lest in CPC group and in self-blood group. There were a great deal of mature osteocytes, which trended to bone casing plys. 4. Transmission electron microscopy: In CPC group the 3rd week some osteoblasts invaded the material, some cells protruded cell projections. The rough endoplasmic reticulum (rER) did not swell evidently. But only few osteoblasts could be found and lots of Osteoclasts could be found. Calcium and new-born bone were integrated directly, but there were lightline between them. This shew they were not firmed up. The 12th week CPC granule density decreased, vacuoles in it were clearly more and larger than the 3rd week in CPC group. some osteoblasts could be found. The cell nucleus was round, rERs swelled. There was the phenomenon of mitochondrion cavitation and mitochondrion crest rupturing. Calcium and new-born bone were integrated directly, there were not lightline between them. In self-blood group the 3rd week CPC granule density more decreased than the 3rd week in CPC group. many preosteoblasts and osteoblasts invaded the material and few Osteoclasts were found. More rERs were found. CPC and the new-born bones were interlaced. There was no fibre between them and they directly formed concrescence. The region between them has blood vessels. In self-blood group the 12th week CPC granule density most decreased, calciums became sparse, vacuoles in it were most and largest, many... |
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