摘要
背景:牵引成骨技术治疗四肢骨缺损和发育不良等有一定的优势,但是有关骨延长区新骨的成骨方式,目前尚存在争议。目的:观察小鼠胫骨骨折愈合过程中与成骨方式有关的骨基质蛋白组织学与基因水平的表达,论证在外界牵张力的作用下骨折愈合方式。设计、时间及地点:组织学和蛋白基因检测,于2007-08/12在中南大学第三附属医院中心实验室完成。材料:8周龄雄性CD-1小鼠36只,体质量25～30g,由中南大学湘雅医学院实验动物中心提供。方法:接受左胫骨中上段骨干横行截骨,安置特制延长外固定架,胫骨牵引过程包括5d静止期,12d牵引期和70d固塑期,牵引期的牵引速率为0.1mm/次,共0.2mm/d。术后于5,9,13,17,24,31d采集左胫骨标本,分别作组织学检查和骨基质蛋白mRNA检测。主要观察指标:①小鼠胫骨牵引成骨模型骨折端组织学变化。②小鼠胫骨牵引成骨骨痂内各种基质蛋白mRNA在不同时间点的表达。结果:组织学检查显示:静止期其修复过程基本与骨折愈合相似;牵引期,被牵引骨痂显示3个典型的生物力学功能区:纤维间区,初始骨基质前沿和微骨柱形成区;固塑早期,牵引骨痂骨性愈合。mRNA检测显示:Ihh在牵引后的第4天可检测到表达,静止期及牵引后期无明显表达。Ⅱ型胶原从截骨后第5天即可检测,直到固塑期1周,但其mRNA表达逐渐减弱,到固塑期第2周即停止表达。X型胶原的表达在牵引期第4天达到高峰,然后逐步下降。骨钙素在截骨第5天尚不能被检测,其mRNA的表达在牵引后期和固塑期早期达高峰。结论:胫骨牵引静止期软骨内成骨和膜内成骨同时存在,但在机械牵张力作用下转为以膜内成骨为主的成骨过程。
BACKGROUND： Distraction osteogenesis has certain advantages in treatment of bone defects and stunted, however, the osteoblast mode in bone lengthening area is still in dispute. OBJECTIVE： To observe the expression of at protein and genetic level in the process of bone healing, furthermore, to justify the healing process of distraction osteogenesis. DESIGN, TIME AND SETTING： The detection at histological and protein gene levels was performed at the Center Laboratory of The Third Xiangya Hospital of Central South University between August and December 2007. MATERIALS： Thirty-six male CD-1 mice, with 8 weeks old, weighing 25-30 g, were supplied by the Experimental Animal Center of Xiangya Hospital of Central South University. METHODS： All animals received osteotomy and placement of the external fixators on the left tibia. Distraction protocol included 5 days latency, 12 days distraction and 70 days consolidation. Distraction rate was 0.1 mm once, and performed 0.2mm per day. The tibiea were collected at 5, 9, 13, 17, 24, 31 days after operation, and analyzed by histological examination and RT-PCR. MAIN OUTCOME MEASURES： The histological change and the expression of mRNA at different time points were observed. RESULTS： Histological analysis demonstrated that the healing process of osteotomic gap was similar to fracture repair in the latency. The distraction callus consisted of fibrous interzone, primary matrix front and microcolum formation during the distraction. In the early stage of consolidation, the distraction gap was bridged by bony callus. The mRNA analysis showed that Ihh expression could be found at 4 days of distraction, and no expression in the rest phase and anaphase of distraction. Co1. Ⅱ could be detected at 5 days to 1 week of osteotomy, but the mRNA expression decreased gradually, and disappeared at 2 weeks of consolidation. The expression of Col .X reached a peak at 4 days of distraction, and then gradually decreased. Osteocalcin could not be found at 5 days of osteotomy, the mRNA expression reached a peak at the anaphase of distraction and early stage of consolidation. CONCLUSION： The endochondral ossification and intramembranous ossification occurred simultaneously in the early phase of distraction. Under the mechanic stretching force, the bone formation has been shifted from endochondral ossification to intramernbranous ossification during distraction osteogenesis.
出处
《中国组织工程研究与临床康复》
CAS
CSCD
北大核心
2009年第2期225-228,共4页
Journal of Clinical Rehabilitative Tissue Engineering Research
