双膝关节盘状半月板MRI分型及损伤特点

目的 探讨膝关节盘状半月板的诊断标准，双膝盘状半月板的MRI分型及损伤特点。 方法 通过对2009年11月－2013年3月，13 936膝大样本量的MRI检查的盘状半月板流行病学研究，筛查出双膝关节盘状半月板956膝，并对诊断为盘状半月板的全部患者行冠状位髁间棘层面半月板宽度与胫骨平台宽度之比（板面比）、矢状位“领结样”改变层面中半月板后角最厚层面的厚度（半月板后角厚度）及矢状位“领结样”改变层数测量并分析；根据盘状半月板MRI表现分为板型、楔型、肥角型；分析双膝盘状半月板分型，比较双膝盘状半月板损伤率与总体损伤率的差别。 结果 956膝盘状半月板中伴撕裂392膝，损伤率为41.0%；筛查出45例90膝双膝盘状半月板，外侧44例，内侧1例，其中板型58膝、楔型32膝，无肥角型，伴盘状半月板撕裂23膝，损伤率为25.5%；双膝盘状半月板的损伤率低于盘状半月板总体平均值。 结论 板面比≥0.20、半月板后角厚度≥4.40 mm、矢状位连续“领结样”改变层数≥3层为盘状半月板的MRI诊断标准；双膝盘状半月板多见于外侧，分型中未见肥角型，损伤率较总体损伤率低。

MRI Classification and Lesion Characteristics of Bilateral Discoid Meniscus

Objective To discuss the diagnostic criteria for and lesion characteristics of bilateral discoid meniscus. Methods discoid meniscus of the knee, and the MRI classification We carried out a study of the discoid meniscus with a large sample, and discoid meniscus of the knee was screened out from Noverber 2009 to March 2013. For all the cases, we measured and analyzed 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 ＂butterfly＂ change layers on sagittal slice. Discoid meniscus was divided into slab type, wedge type and hypertrophied-horn type. We analyzed the classification of bilateral discoid meniscus, and compared lesion rate of bilateral discoid meniscus and the general lesion rate of discoid meniscus. Results In all 956 cases of discoid meniscus, there were 392 cases of meniscal tears, and the lesion rate was 41.0%. Forty-five patients （90 knees） of bilateral discoid meniscus were screened out （44 patients of lateral and 1 patient of medial）, including 58 knees of slab type, 32 knees of wedge type, without cases of hypertrophied-horn type. There were 23 cases of meniscal tears, and the lesion rate was 25.5%. The lesion rate of bilateral discoid meniscus was lower than the general rate of discoid meniscus. Conclusions Three MRI diagnostic criteria for discoid meniscus are the ratio of the width of meniscus to that of tibial plateau≥0.20, the thickest thickness of the meniscus posterior horn on ＂butterfly＂ change layers ≥ 4.40 mm, and 3 or more than 3 consecutive layers discoid meniscus ＂butterfly＂ change. Bilateral discoid meniscus is more common in the lateral side, and there is no hypertrophied-horn type in classification. The lesion rate of bilateral discoid meniscus is lower than the general rate.