异种脱蛋白骨复合物修复大段骨缺损的血管化观察

背景: 异种骨修复动物大段骨缺损过程中血管化的报道较少.目的: 验证异种脱蛋白骨作为组织工程支架材料修复长骨大段缺损成骨过程中的血管化特点.设计、时间及地点: 随机对照动物实验,于2005-03/2007-02在解放军第三军医大学完成.材料: 山羊24只,体质量(22.5±2.5)kg,右侧胫骨中下段截除胫骨总长度20%形成节段性骨缺损.方法: 24只实验山羊随机分为2组,实验组16只动物植入异种脱蛋白骨 自体间充质干细胞 重组人骨形态发生蛋白2,用半环槽式外固定器固定;以另8只植入自体骨为对照.术后每隔4周进行股动脉墨汁灌注后,取新骨组织制成厚切片.主要观察指标: ①大体解剖及影像学观察新骨血管化情况.②厚切片观察新骨血管网,并用Image-proplus真彩图像分析软件测量血管数目和面积.结果: 所有实验山羊术后伤口无溃烂、流脓,无死亡.①动物肌肉和软组织已经被墨汁黑染,皮下、肌肉筋膜和骨膜可见血管大小、分支、走行方向及相互吻合呈网状.术后4周骨缺损区出现植入物边缘毛糙,8周出现大小不等、形状不规则的透光性骨吸收区.12周以后,两组骨缺损区两断端之间高密度钙化影,新生骨与两断端完全相连接.②术后4～24周,实验组与对照组血管表现数目逐渐增多,排列渐趋规则,血管大小、分布区域趋向均匀.两组血管数目和面积相比,差异均无显著性意义(P>0.05).结论: 异种脱蛋白骨复合物材料修复大动物大块骨缺损过程中血管化程度与自体骨相当.

Observation on vascularization of large segmental bone defect repaired by heterogeneous deproteinized bone

BACKGROUND: There are few reports about vascularization in the repairing of bone defect by heterogeneous deproteinized bone.OBJECTIVE: To verify the vascularization characteristics of heterogeneous deproteinized bone, tissue engineering scaffold material, in the repairing of large segmental bone defect.DESIGN, TIME AND SETTING: The randomized controlled animal experiment was performed between March 2005 and February 2007 at the Third Military Medical University, Chongqing, China.MATERIALS: Twenty-four 10 to 12 months old goats, weighing (22.5±2.5)kg, were obtained from the Animal Center of the Third Military Medical University, Chongqing, China. Segmental bone defects of 20 percent right tibia middle and inferior diaphysis of the 24 goats were made.METHODS: The 24 goats were divided into test group (n=16) and control group (n=8) randomly. Goats in test group were implanted with deproteinized bone+autologous MSCs+recombinant human bone morphogenetic protein-2 (rhBMP-2), goats in control group were implanted with autograft bone, and all fixed with half-ring sulcated external fixator. Every 4 weeks, 3 goats were killed after ink perfusing through femoral artery. A thick slice of new bone tissue was made to observe the vascularization.MAIN OUTCOME MEASURES: Vascularization of new bone observed through gross anatomy and imaging; vascular network of new bone observed through thick section, blood vessel amount and area measured by Image-proplus really image analysis software.RESULTS: No goat was infected or dead. Animal soft tissue was dyed black, blood vessels'size, ditribution and network structure were observed in subcutaneous tissue, fascia and periosteum. At 4 weeks postoperation implant margin became crude in the defect area; at 8 weeks postoperation transparent bone absorbing area of different size and irregular shape appeared; after 12 weeks postoperation high-dense calcification shadow appeared at the ends of defect bone and new bone connected with the ends completely. On 4 to 24 weeks postoperation, the blood vessel amount became large, alignment became regular, and their size and distribution became uniform. It showed no significant difference in blood vessel amount and area between 2 groups (P>0.05).CONCLUSION: Composite of heterogeneous deproteinized bone+autologous MSCs+rhBMP-2 has the same vascularization degree. of autogeneous bone graft in repairing of large segmental tibia defect.