膝关节内侧盘状半月板MRI分型及损伤特点研究

The MRI Classification and Lesion Characteristics of Medial Discoid Meniscus

目的探讨膝关节内侧盘状半月板的MRI诊断标准、分型及损伤特点。方法回顾性分析2009年11月-2015年3月行膝关节MRI检查的患者资料,筛查出内侧盘状半月板患者26例(28个患膝)进行研究,对冠状位髁间棘层面内侧半月板宽度与胫骨平台宽度之比(板面比)、矢状位半月板后角最厚层面厚度(半月板后角厚度)与矢状位"领结样"改变层数数据进行测量、分析;同时根据MRI结果将内侧盘状半月板分为完全型与不完全型,比较两种类型内侧盘状半月板的损伤率。结果 28个内侧盘状半月板中,完全型16个,不完全型12个。板面比为0.29±0.06;半月板后角厚度为(5.31±0.92)mm。另外,盘状半月板伴撕裂17个,损伤率为60.7%,其中完全型损伤率为81.2%,不完全型损伤率为33.3%,完全型内侧盘状半月板损伤率高于不完全型,差异有统计学意义(P<0.05)。结论膝关节内侧盘状半月板MRI诊断标准为矢状位连续"领结样"改变层数≥3层、板面比≥0.20、半月板后角厚度≥4.40 mm;内侧盘状半月板分为完全型和不完全型,完全型损伤率大于不完全型。

ObjectiveTo discuss the MRI diagnostic criteria, classification and lesion characteristics of medial discoid meniscus of the knee. MethodsWe retrospectively analyzed the clinical data of all patients who accepted MRI examination of knee from November 2009 to March 2015.Twenty-six of them （28 knees） with medial discoid meniscus were screened out.We measured and analyzed in all cases the ratio of the width of meniscus to that of tibial plateau on coronal slice, and the thickest thickness of the meniscus posterior horn on sagittal slice.All cases were divided into complete and incomplete type according to MRI findings, and then we compared the lesion rate of the two types of medial discoid meniscus. ResultsTwenty-eight cases were divided into complete type （n=16） and incomplete type （n=12）;there were 17 cases of medial discoid meniscal tears, with a lesion rate of 60.7%.The ratio of the width of meniscus to that of tibial plateau on coronal slice was 0.29±0.06, and the thickest thickness of the meniscus posterior horn was （5.31±0.92） mm.The lesion rate of complete type was 81.2%, and 33.3% of the incomplete type.The lesion rate of the complete type was higher than that of the incomplete type, and the difference was statistically significant （P 〈 0.05）. ConclusionsThree MRI diagnostic criteria for medial discoid meniscus are 3 or more than 3 consecutive layers discoid meniscus ＂tie-like＂ change in sagittal slice, the ratio of the width of meniscus to that of tibial plateau≥0.20, and the thickest thickness of the meniscus posterior horn≥4.40 mm.Medial discoid meniscuses are divided into complete and incomplete type; the lesion rate of complete type of medial discoid meniscus is higher than that of the incomplete type.