管型石膏伸直位固定法对兔KOA模型膝关节X线及MRI检查改变的研究

X-ray and MRI Changes of Knee Joint in Rabbit KOA Model by Tubular Plaster Extension Fixation

目的观察管型石膏伸直位固定法制备4周、6周兔膝骨关节炎(KOA)模型右后肢膝关节X线及MRI检查的改变,探讨兔KOA模型的X线及MRI分期。方法30只雄性兔随机分为空白组、模型4周组、模型6周组,每组10只,采取管型石膏伸直位固定法对兔右后肢制备兔KOA模型,造模结束后对兔右后肢膝关节行X线及MRI检查。通过K-L法对X线检查结果进行分级,比较骨质增生及关节间隙狭窄情况;通过Recht法对MRI检查结果进行分级,比较软骨损伤情况。结果X线检查可见:空白组兔膝关节骨质形态未见异常,无骨质增生;模型4周组兔膝关节边缘轻度骨质增生,模型6周组兔膝关节边缘骨赘形成,关节间隙均有可疑狭窄。模型4、6周组K-L分级均高于空白组(P均<0.05);模型6周组K-L分级高于模型4周组(P<0.05)。MRI检查可见:空白组兔膝关节软骨信号均匀,表面光滑;模型4周组兔膝关节软骨内信号减低,软骨表面光滑;模型6周组膝关节软骨表面不规则,软骨轻度缺损,缺损程度小于50%。模型4、6周组Recht分级均高于空白组(P均<0.05);模型6周组Recht分级高于模型4周组(P<0.05)。结论管型石膏伸直位固定法可成功制备符合X线、MRI检查表现的兔KOA模型,且随造模时间增加,影像学分级逐渐升高。

Objective To observe the changes of X-ray and MRI examination of the knee joint of the right hind limb in rabbits with knee osteoarthritis(KOA)for 4 and 6 weeks after tubular plaster extension fixation,and to explore the X-ray and MRI staging of rabbit KOA model.Methods Thirty male rabbits were randomly divided into blank control group,4-week model group and 6-week model group with ten rabbits in each group.Rabbit KOA model was established by fixing rabbit knee joint of the right hind limb with tubular plaster extension fixation.The right knee was examined by X-ray and MRI after the model was established.The X-ray results were graded by K-L method and the osteoporosis and joint space stenosis were compared.The MRI results were graded by Recht method to compare the cartilage injury.Results X-ray examination showed that there was no abnormal bone morphology and no osteoporosis in the knee joint of rabbits in the blank group;the knee joint of rabbits in the 4-week group and the 6-week group had different degrees of osteoporosis and suspicious narrowing of joint space.The K-L grade in the 4-week and 6-week group was higher than that in the blank group(P all<0.05);the K-L grade in the 6-week group was higher than that in the 4-week group(P<0.05).MRI examination showed that the cartilage signal of knee joint of rabbits in blank group was uniform and smooth;the cartilage signal of 4 weeks group and 6 weeks group of model decreased in different degrees,and the cartilage surface or defect.Recht grade of 4 and 6 weeks group of model was higher than that of blank group(P all<0.05);recht grade of 6 weeks group of model was higher than that of 4 weeks group of model(P<0.05).Conclusion The rabbit KOA model conforming to the X-ray and MRI examinations can be successfully prepared by the method of tubular plaster extension fixation and with the increase of modeling time and gradually increased image grading.