Ilizarov牵张技术对挛缩跟腱组织学改变的实验研究

摘要

目的 探讨Ilizarov牵张技术的牵拉应力对挛缩跟腱组织学的影响.方法 18只狗右后肢应用Ilizarov外固定支架中立位固定1周后开始牵拉,1 mm/d,分2次调整,连续3周,X线摄片确定足下垂15°,再维持固定3周,随机选取9只动物处死取材(挛缩组)；余动物再以同样的速度和方法牵拉矫正3周后处死取材(牵拉组)；所取健侧标本合并为对照组.(1) HE染色观察腱细胞排列分布,胶原纤维形态,并分析腱网膜厚度变化；(2)以苦味酸-天狼猩红染色法,偏振光显微镜观察Ⅰ、Ⅲ胶原,并分析二者含量变化；(3)采用间苯三酚分光光度法,测定蛋白多糖(主要为葡糖氨基葡聚糖)含量.结果 (1)挛缩组腱细胞与胶原纤维间隙不明显,腱细胞呈梭形,囊状,胶原纤维束扭曲,排列散乱,难见细胞间质.腱网膜厚度与健侧(对照组)有明显差异；牵拉组,腱细胞呈圆形或卵圆形,在胶原束间成串排列,细胞与胶原纤维间有基质间隔,见炎症细胞,形态与正常腱组织相似.腱网膜厚度与健侧无明显差异.(2)偏振光显微镜下,挛缩组Ⅰ、Ⅲ胶原构成比与对照组有明显差异,牵拉组Ⅰ、Ⅲ胶原构成比与健侧无明显差异.(3)挛缩组跟腱蛋白多糖含量明显减少,牵拉组基本恢复到正常水平.结论 在Ilizarov牵张技术牵拉下,挛缩退化的跟腱组织在组织学上可基本恢复正常.%Objective To study the histologic changes of contracture Achilles tendon under Ilizarov distraction technique.Methods Eighteen dogs were installed ilizarov external fixation frames on the right hind leg in a neutral position.Pull traction started 1 week postoperatively with speed of 1 mm/day for 3 weeks.After 15 degrees of foot drop,the fixation was still maintained for 3 weeks.Nine animals were randomly selected and put to death (Contracture group),other animals corrected for 3 weeks with the same speed and methods,then put to death (Force group),health specimens as control group.(1)Observe tendon cells arranged distribution and collagen fiber form with HE dyeing,and analysis of tendon retinal thickness with image analysis software.(2)Observe collagen Ⅰ and Ⅲ with picrosirius red dying,and analyzed both content changes with image analysis software.(3)Determination of protein contents of polysaccharide with phloroglucinol spectrophotometry.Results (1)In the contracture group,the collagenous fibre gap was not obvious,the tendon cell assumes spindle-shaped,saccate,the collagen fibrous bundle distortion,the arrangement was scattered in disorder,difficult to see the intercellular substance.Tendon retinal thickness showed obvious differences with the health side (Control group).In the force group,the tendon cells were round or oval,located in collagen bundles in a string of alignment,inflammatory cells were seen.Tendon retinal thickness showed no differences with the health side.(2)With polarized light microscopy,the collagen Ⅰ and collagen Ⅲ composition proportion in the contracture group showed obvious differences with the control group,force group had not obvious differences with health side.(3)The content of polysaccharide in the contracture group were obviously reduced,while force group returned to normal level.Conclusion The tissue form of contracture Achilles tendon can recovered to normal with the Ilizarov technology.