| In this study, We employed a recent membrane guided tissue regeneration technique to enhance healing of long bone defect. We combined guided bone regeneration with osteoinductive and osteoconductive effects by using collagen membrane and bone autograft or porously alloplastic bone plate associated with autogenous bone marrow.The purpose of this study is to observe how collagen membrane guided bone regeneration in long bone and learn histocompatibility or structural characteristics of collagen membrane,another purpose of this study is to explore the mechanism of guided bone regeneration. 1. An experimental study of guided bone regeneration in the rabbit radiususing collagen membrane with surface-decalcified bone allograft Methods:Thirty adult New Zealand rabbits were divided into two groups at random, standard defects of 10mm in radii were created, the self-control method was used,one was experimental group, the other was control group.The experimental group was bone defect with transplantation of collagen membrane and surface-decalcified bone allograft, the control group was the same bone defect with only transplantation of surface-decalcified bone allograft. Histological analysis, X-ray films and immunohistochemical examination were taken at 2, 4, 6, 8, 10, 12 week postoperatively. The results were following: In experimental group, there were distinctive periosteal reaction and lots of callus growth in transplantation area, consistent callus finally bridging the gaps of defect. New bone proliferated in the way of intramembranous ossification and entochondrostosis, mature periosteum and bone marrow cavity were gradually formed, bone defect healed completely, BMP positive distributed in osteocytes of bone ends, proliferating periosteum, medullary cavity and endosteum. In control group, the defect was occupied bysurrounding connective tissue, it made the process of new bone growth and mature bone replacement delay. The results indicated following conclusions: As a physical barrier, collagen membrane has capacity to block surrounding connective tissue out of defect, thereby giving preference to osteoblsts to repopulate the defect, which are able to regenerate the desired type of bone . Endogenic BMP with exogenic BMP can greatly be concentrated and distributed in the tube of collagen membrane, distributive characteristics of BMP exerts an influence on cellular resources and bone healing pattern. 2. . An experimental study of guided bone regeneration using collagenmembrane with bone autograft combined autogenous bone marrow Methods: 10mm radius defect was performed bilaterally in thirty adult New Zealand rabbits, self-control study was used,one defect was grafted by collagen membrane with bone autograft combined autogenous bone marrow as a experimental group,the contralateral defect was grafted by bone autograft with autogenous bone marrow as a control group. Histological observation was performed at 2, 4, 6, 8, 10, 12week postoperatively, biomechanical test was taken at 12 week postoperatively. Results of this experiment reflected: During the application period, collagen membrane had no evidence of displacement or collapse, it showed no foreign body or rejection reaction, it began to degrade at 6 week,entirely degraded at 8 week,degradable products did not destroy bone regeneration process. New bone remarkably formed, bone trabecula arranged sequently,small vessel and nervous fiber proliferated apparently, the bone defect had been completely healed. While in control group, new bone growth and mature bone replacement were slow owing to ingrowth of connective tissue. Biomechanical examination showed that experimental group had distinctively statistical significance, experimental group prevaled over control group according to biomechanical test scores (p<0.01). The results indicated following conclusions: Collagen membrane have a good biocompatibility and degradation, its degradative speed and extent match the completion time of tissue regeneration. Transplantationof bone autograft with auto...
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