筋膜瓣包裹组织工程骨修复兔大段骨缺损的动态变化

Dynamic changes in tissue-engineered bone encapsulated with fascial flap for repairing rabbit large bone defects

背景:组织工程骨的血管化是构建过程中的关键环节。目的:动态观察带蒂筋膜瓣包裹组织工程骨的血管化过程,以及其修复大段骨缺损的一般规律。设计、时间及地点:随机对照动物实验,于2005-10/2006-04在南方医科大学南方医院创伤骨科实验室完成。材料:6月龄健康新西兰大白兔12只双侧髂骨抽取骨髓分离骨髓基质干细胞诱导分化成骨细胞。圆柱状(3×15)mm多孔β-磷酸三钙为法国贝奥路公司产品。方法:将成骨细胞与β-磷酸三钙复合培养7d后细胞量达到1×109L-1为组织工程骨,实验组兔左侧前肢内侧剥离带蒂筋膜瓣(2×1.5)cm包裹圆柱状组织工程骨植入1.5cm桡骨缺损处,对照组于同一只兔右侧桡骨1.5cm骨缺损处植入未包裹组织工程骨。主要观察指标:植入后2,4,6,8,12周进行大体观察、组织学、放射学、骨密度和放射性核素骨显像检测。结果:①从第4周以后各时间点实验组修复效果均优于对照组,X射线相对阻射值定量分析实验组的评分高于对照组(P<0.05),骨密度值高于对照组(P<0.05),放射性强度高于对照组(P<0.05)。②从第4周以后各个观察点实验组在血管化程度、新骨形成量、材料降解速度、骨缺损修复时间、骨修复改建质量都优于对照组。结论:采用蒂筋膜瓣包裹组织工程骨修复骨缺损,4周后,在血管化程度、新骨形成量、材料降解速度及骨缺损修复时间方面均优于无筋膜包裹的组织工程骨,提示早期的快速血管化直接影响到骨缺损修复的全过程。

BACKGROUND： The vascularization is the key point to construct tissue-engineered bone. OBJECTIVE： To dynamically study the vascularization and bone defect reparation rule about tissue-engineered bone wrapped by pedicle fascial flap to repair large bone defect. DESIGN, TIME AND SETTING： The randomized control animal experiment was performed at the Laboratory of Orthopaedic Trauma, Nanfang Hospital, Southern Medical University from OCtober 2005 to April 2006. MATERIALS： Bone marrow stromal stem cells （BMSCs） harvested from the bilateral iliac bone of twelve six-month old healthy New Zealand rabbits were used to induce osteoblasts. （3×15） mm cylindrical porous β-tricalcium phosphate was purchased from France Beiaolu. METHODS： After co-culture of osteoblasts and β -tricalcium phosphate for 7 days, tissue-engineered bone was obtained when cell number was 1×10^9L^-1. Tissue-engineered bone wrapped by pedicle fascial flap was implanted into the 1.5 cm radial defect region of anterior left limb of rabbits in the experimental group. Tissue-engineered bone was implanted into ~e 1.5 cm right radial defect region of the same rabbits in the control group. MAIN OUTCOME MEASURES： At 2, 4, 6, 8 and 12 weeks after operation, specimen observation, histology, radiology, bone density and radionuclide bone scan were used. RESULTS： Bone reparation in the experimental group was better than in the control group from 4 weeks after operation. The quantitative analysis on X-ray was higher in the experimental group than in the control group （P 〈 0.05）. Bone density and the intensity of radioactivity were higher in the experimental group than in the control group （P 〈 0.05）. After 4 weeks, at every time point, the experimental group was better than the control group not only in vascularized degree, new bone formation and materials degradation speed, but also in bone repair time and bone rebuild quality. CONCLUSION： Four weeks later, vascularized degree, new bone formation, materials degradation speed and bone repair time were better in rabbits treated with tissue-engineered bone wrapped by pedicle fascial flap for repair bone defect than in rabbits only treated with tissue-engineered bone. This indicates that early quick vascularization directly influences the whole course of bone defect reparation.