Experimental Study About The Effect Of Acellular Porcine Pericardium Guided Bone Regeneration In Rabbit Femoral Bone Defect

Objective:To evaluate the degradation of APP, and the effect of APP on bone regeneration in rabbit femoral bone defects.Method:Under aseptic conditions, choose fresh porcine pericardium.Rinse thoroughly, 0.05mol/L Na Cl and 1.5mol/L Na Cl soaked with 24 hours,0.1% trypsin+0.02 EDTA digested for 24 hours,immerse with 0.5% Triton X-100,crosslinking with 0.03%glutaraldehyde,finally APP preparation.Select 18 adult New Zealand rabbits, making their bilateral distal femoral bone defect 8*8*5mm,randomly in one side covered with APP(APP group), the other side with no membrane(Control group).Each 6rabbits were killed on fourth weeks,eighth week and twelfth week after operation,the femur were isolated from the specimen.The following indicators were measured: general observation, X-ray examination, bone mineral density(BMD) measurement and histological observation.Results: â‘  General observation: Neither infected nor died. Fiber kystis were found in operation area on three observation points.After 4 weeks, there was no significant difference between two groups.After 8 weeks,lots of new bone formation in the edge of bone defect in APP group.After 12 weeks,the surface of bone defect in APP group was flatter than that in control group.â‘¡X-ray observation:After 4 weeks,low density shadow on bone defect area can be seen in APP group,similar with control group.After 8 weeks, trabecular bones can be found in the edge of bone defect in APP group.After 12 weeks,high density shadow on bone defect area can be seen in APP group,thicker trabecular bones can be found.â‘¢Measurement of BMD: After 4,8 and 12 weeks, the BMD value of APP group were higher than that in control group, there were statistically significant(P < 0.05).â‘£Histological observation:Histological examination showed cellular constituents were removed completely,the arrangement of collagen fibers were regular.After 4 weeks, APP surround with amount of inflammatory cell infiltration in the bone defect area,and the number of trabecular bones were little more than that of the control group.After 8 weeks,APP has vascular invasion, and the number of trabecular bones were more than control group.After 12 weeks,fibroblasts grow into the APP, and the thickness of the fiber is2/3.The trabeculars bone were remodeling and thickening.Muscle fibers occupy the central of bone defects in control group.Conclusion: â‘ Comprehensive high and low permeability liquid, trypsin and EDTA digestion, Triton X-100 immerse,can effectively removed cells and good preservation of collagen structure.â‘¡APP plays a good role in guided bone regeneration,speed up osteogenesis and slow degradation can provide enough time for bone regeneration.â‘¢In the process of absorption, fiber kystis formated around the APP, because of the existence of cytotoxicity about glutaraldehyde probably.