小肠黏膜下层/β-磷酸三钙复合骨支架材料修复大段骨缺损的能力

Small intestinal submucosa with beta-tricalcium phosphate as the bone scaffold for segmental bone defect

目的:观察小肠黏膜下层和小肠黏膜下层/β-磷酸三钙复合骨支架材料修复骨缺损的能力,评估其作为骨支架材料的应用价值。方法:实验于2003-10/2004-10在上海交通大学附属医院上海市第六人民医院动物实验室完成。取新西兰大白兔48只,随机分为小肠黏膜下层/β-磷酸三钙复合骨支架材料组、β-磷酸三钙组、小肠黏膜下层组和空白组4组,于双侧桡骨骨干中段做20mm长的骨缺损,每组的骨缺损处分别植入小肠黏膜下层/β-磷酸三钙复合骨支架材料、β-磷酸三钙、小肠黏膜下层,空白组不加任何添加物。分别在术后3,6,12、18周于植入处取材,并进行X射线摄片,组织学观察,新骨成骨面积定量分析和力学测试。结果:实验动物48只均进入结果分析,大体观察、X射线检查和组织学显示小肠黏膜下层/β-磷酸三钙复合骨支架材料组和β-磷酸三钙组均表现良好的成骨,材料逐渐吸收并由新生骨替代。小肠黏膜下层/β-磷酸三钙复合骨支架材料组比β-磷酸三钙组6周时骨痂形成量多,而且18周时塑形也更为完全。小肠黏膜下层组仅在两端骨断端和缺损区尺骨边缘有少量的成骨,材料逐渐吸收变软。空白组在骨缺损区无明显成骨。新骨成骨面积定量分析显示小肠黏膜下层/β-磷酸三钙复合骨支架材料组3,6。

AIM:To investigate the ability of small intestinal submucosa or the compound o f small intestinal submucosa and beta tricalcium phosphate(SIS/β TCP) to repa ir segmental bone defect and evaluate the feasibility of them used as bone subst itute materials. METHODS:The experiment was completed in the Laboratory for Animals,Shanghai Si xth People's Hospital Affiliated to Shanghai Jiaotong University from October 12 to October 2004.The animal model of bone defect(20 mm) was made on the middle p art of bilateral radius shafts of 48 New Zealand white rabbits,which were random ly and equally divided into the SIS/β TCPgroup(the defect was repaired with SI S/β TCP),β TCP group(with β TCP),SIS group(with SIS) and blank control gro up(the defect was left unrepaired).The ability of bone defect repair was evaluat ed by gross observation,histopathological study,X ray,quantitative analysis for the area of new bone formation and biomechanical analysis(bending strength) at 3,6,12 and 18 weeks after repair. RESULTS:All the animals finished the analysis of the results.It was shown from gross observation,histopathological study and X ray that osteogenesis was good ,the repair materials were confluent gradually and then substituted by new bone in both SIS/β TCP group and β TCP group.More calluses formed at 3 weeks and better bone remodeled at 18 weeks in the SIS/β TCP group than in the β TCP g roup,while only a few calluses formed at the two broken ends of bones and along the border of ulnar defect,and the SIS was confluent gradually and became soft i n the SIS group.In the blank group no obvious bone formation was found in the bo ne defect.Computerized quantitative analysis for the area of new bone formation showed that the area was significantly larger in the SIS/β TCP group than in t he β TCP group at 3,6 and 12 weeks(P< 0.05),except at 18 weeks.There were no s ignificant differences in bone formation between the two groups.Biomechanical an alysis showed that bending strength of three folding points in SIS/β TCP group were significant higher,as compared with the β TCP group at 6,12 and 18 weeks after implantation(P< 0.05). CONCLUSION:As used for the repair of segmental bone defect,SIS/β TCP forms m ore calluses and remodels better than β TCP does,so the former can be used as a kind of bone substitute material.The formation of new bone is worst using SIS as the substitute material,so SIS is improper to repair segmental bone defect.