髌骨倾斜对兔髌骨关节软骨损害的实验研究

Experimental study on rabbit articular cartilage damage caused by patella tilt

目的建立兔髌骨倾斜的模型并观察髌股关节软骨损害的变化,为临床治疗髌股关节疾病提供实验依据。方法新西兰大白兔24只,随机分3组,每组8只,行右膝髌骨内侧支持带松解和外侧支持带紧缩术,术后不固定右膝关节。左膝髌骨为对照组。分别于术后第2周、4周、8周处死取材,分别进行髌骨倾斜角CT测量、髌骨关节面软骨大体观察、软骨组织Mankin评分。结果(1)实验侧髌骨倾斜角明显大于对照侧;(2)术后4周可见关节软骨软化,色泽晦暗,裂隙形成;术后8周关节软骨粗糙,有大的裂隙且色泽晦暗;对照组无软骨退变;(3)HE染色光镜下观察关节软骨,术后4周时,关节软骨轻度变性,可见软骨细胞变扁,表面不规则,术后8周时,软骨明显变性,可见软骨细胞增殖,排列紊乱,基质减少,潮线不完整。根据软骨Mankin评分,术后4、8周时右膝实验组得分明显高于左膝空白对照组,相比较有显著的统计学意义(P<0.05)。结论兔髌骨倾斜后4周,髌骨外侧关节面软骨出现软骨软化,随着时间的延长软骨退变进一步加重,为治疗髌股关节软骨疾病提供实验依据。

Objective To establish a rabbit model of patellar tilt and observe the change of the patellofemoral cartilage damage,which can provide experimental basis for the clinical treatment of patellofemoral joint diseases.Methods Twenty-four New Zealand rabbits were randomly divided into three groups.The right knee was the experimental side which was operated to make the patella tilted.The left knee was used as the normal control.The animals were sacrificed in the 2ndweek,4thweek,and 8thweek after the operation.The patellar tilt angle on the CT scanning was measured,gross observation and Mankin scores were also performed.Results（1） The results revealed that the patellar tilt angle of the experimental side was obviously larger than that of the control side.（2） The joint degeneration,cartilage softening,dull color,and crack formation were observed in the ^4thweek after the operation.The joint degeneration increased in the ^8thweek after the operation;while there was no degeneration on the control side of the knee.（3） HE staining results.The degeneration of cartilage began in the 4^thweek after the operation.The most severe degeneration of the cartilage included chondrocytes proliferation and disorderly arrangement,the matrix reduction,and incomplete tide line.The Mankin score of the experimental side was significantly higher than that of the control side in the 4thand 8thweek after the operation（P〈0.05）.Conclusion The cartilage of the lateral joint surface presented chondromalacia 4 weeks after the rabbit patellar tilt.The cartilage degeneration will aggravate with the time.These findings can provide experimental basis for the treatment of cartilage diseases of patellofemoral joint.