膝关节半月板桶柄状撕裂的磁共振影像学特征分析

Magnetic resonance imaging features of bucket handle meniscus tear of knee and their diagnostic values

目的分析、总结膝关节半月板桶柄状撕裂(bucket handle meniscus tears,BHMT)的MRI特征表现及其诊断价值。方法回顾性分析2015-2019年我院75例膝关节半月板MRI图像,其中25例经关节镜证实为半月板桶柄状撕裂,分析BHMT的MRI影像特征包括髁间窝碎片征、双前交叉韧带征、双后交叉韧带征、半月板翻转征/双前角征、空领结征、外周残半月板征。以关节镜结果为金标准,分别计算不同MRI表现诊断桶柄状撕裂的敏感度、特异性、符合率、阳性预测值及阴性预测值,并同时评价指标A(髁间窝碎片征、双前交叉征、双后交叉征、半月板翻转征这四种征象中至少1种)与指标B(空领结征、外周残半月板征中至少1种)的联合诊断价值,两个指标均符合可以诊断BHMT。结果在25例BHMT中,MRI影像出现空领结征22例、髁间窝碎片征23例、双前交叉征5例、双后交叉征18例、半月板翻转征/双前角征6例、外周残半月板征22例;6种征象中,髁间窝碎片征诊断BMHT的敏感度为92.0%,符合率为90.7%,阴性预测值为96.2%,在6个指标中最高。A和B组合指标的特异性、符合率、阳性预测值较单独征象提高,分别为98.0%、94.7%、96.2%。结论膝关节半月板桶柄状撕裂具有较典型的MRI特征表现,MRI可作为诊断半月板桶柄状撕裂的重要辅助检查,其中髁间窝碎片征是诊断桶柄状撕裂最可靠的征象。

Objective To analyze MRI features of bucket handle meniscus tears(BHMT)of knee and their diagnostic values.Methods MRI images of 75 cases with meniscus in our hospital from 2015 to 2019 were analyzed retrospectively.Of the 75 cases,25 cases were confirmed to be bucket handle meniscus tear by arthroscopy.Analysis of MRI image features of BHMT included fragment in intercondylar notch sign,double anterior cruciate ligament(ACL)sign,double posterior cruciate ligament(PCL)sign,flipped meniscus sign/double anterior horn,absent bow tie sign,and peripheral residual meniscus sign.The sensitivity,specificity,accuracy,positive predictive value and negative predictive value were calculated,respectively.The diagnostic performance of combination of indicator A(had at least one of the former 4 signs)and indicator B(had at least one of the latter 2 signs)was also evaluated.Results In 25 cases of BHMT,22 cases had absent bow tie sign,23 cases had fragment in intercondylar notch sign,5 cases had double ACL sign,18 cases had double PCL sign,6 cases had flipped meniscus/double anterior horn,and 22 cases had peripheral residual meniscus sign.Among the six signs,the"fragment in intercondylar notch sign"had the highest sensitivity(92.0%),accuracy(90.7%)and negative predictive value(96.2%).Combination of the indicator A and B had greater diagnostic performance with specificity of 98.0%,accuracy of 94.7%,and positive predictive value of 96.2%.Conclusion Bucket handle meniscus tears(BHMT)of knee joint has typical imaging features on MRI.Among them,fragment in intercondylar notch sign is the most basic and reliable sign for the diagnosis of BHMT.