半月板切除对急性关节软骨损伤愈合影响的实验研究

目的　探讨半月板切除对急性关节软骨损伤 (缺损 )愈合的影响。方法　分离收集 5月龄新西兰兔 35只。,将新西兰兔的股骨内髁行钻孔术造成深达软骨下骨的全层关节软骨缺损模型 ,右膝为实验组 ,切除半月板 ;左膝为对照组 ,保留半月板 ,于 10周取材行大体、组织学、透射电镜观察。结果　大体观察 :10周时对照组关节软骨缺损已由泛白色的类似于正常关节软骨的组织修复 ,而实验组修复组织表面有裂隙、剥脱等迹象。组织学观察 :10周时对照组的关节软骨缺损已基本由软骨下骨的软骨细胞层修复 ,而实验组修复组织表层软骨结构存在裂隙 (纤维性变 )、剥脱等不良改变。透射电镜观察显示 :10周时实验组修复组织表层软骨细胞很多发生凋亡 ,而对照组软骨细胞结构基本正常。结论　表明半月板切除诱发了全层关节软骨缺损修复组织表层软骨结构中的软骨细胞发生凋亡 ,导致裂隙、剥脱等不良改变。半月板是不可缺的生理结构 ,它有极其重要生物学功能 ,即通过维持正常的生物力学环境 ,保证急性关节软骨损伤修复

An Experimental Study of the Healing of Acute Articular Cartilage Injuries under the Influence of Meniscectomy

Objective This study examined the healing of acute articular cartilage injuries under the influence of meniscectomy.Methods New Zealand white rabbits were used for experiment. Cylindrical articualr cartilage defect with exposure of subcondral bone was surgically generated on the bilateral medial femoral condyli. The meniscus of the right knee was removed while the left knee was used as contralateral control by preserving its meniscus. The healing of articular cartilage (AC) defects was evaluated gross morphologically and histologically using both light microscopy and transmission electron microscopy (TEM). Results Gross morphologically, the surface of articular cartilage defects in the contralateral control knee looked normal in structure apart from its pale appearance at 10 weeks; while the right knees showed irregular surface and some clefts and loss of AC surface layer histologically, articular-like cartilage was formed in the repaired defect, which might be regenerated by condrocytes proliferation originated from subcondrol bone in the contralateral control knee at 10 weeks. In contrast, there was degenerative sign of the repaired articular-like cartilage in the right knees, which was characterized with surface clefts (fibrilillation) and detachment of surface AC. TEM showed many apoptotic chondrocytes in the experiment group, while there was normal cellular structure found in the contralateral controlat 10 weeks. Conclusion Meniscectomy was able to induce apoptosis of condrocytes, surface clefts and detachment of the repaired articular cartilage defect. Meniscus is a very important anatomical structure, which execute relevant biological function, i.e. by providing mechanical stability to the knee joint to ensure repair of the acute articular cartilage injury.