超声检查对膝关节外侧盘状半月板的诊断价值

Diagnostic value of ultrasound in the discoid lateral meniscus of the knee

目的:基于外侧盘状半月板(discoid lateral meniscus,DLM)与形态正常外侧半月板(normal lateral meniscus,NLM)之间的解剖学差异,设置具有区分二者潜能的超声检查参数,并探讨这些参数对DLM的诊断价值。方法:收集2019年10月至2020年6月住院治疗的DLM患者(DLM组,66例)和患有其他膝关节疾病的NLM患者(NLM组,132例)。DLM组男18例,女48例;年龄3~60(36.9±12.1)岁。NLM组男36例,女96例;年龄3~60(40.0±12.2)岁。采用飞利浦高频(3.0~12.0 MHz)线阵超声探头检查两组患者膝关节外侧半月板,分别测量外侧半月板前角厚度、前角宽度、前角夹角角度、体部厚度、体部宽度、体部夹角角度、后角厚度、后角宽度以及后角夹角角度共9个参数。采用独立样本t检验分析DLM组与NLM组之间所测参数差异。采用接收者工作特征(receiver operating characteristic,ROC)曲线评估各参数对DLM的诊断界值,以及相应的灵敏性、特异性、阳性预测值、阴性预测值及ROC曲线下面积(area under the ROC curve,AUC)。结果:DLM组与NLM组之间的9项超声测量参数差异均有统计学意义(P<0.001)。经ROC曲线分析方法评估这9项超声参数对DLM的诊断界值及诊断效能,结果显示前角夹角角度、体部夹角角度和后角夹角角度的诊断界值分别为25.85°、24.85°和29.15°,其灵敏度、特异度、阴性预测值、阳性预测值及AUC均明显高于其他参数,分别为:88%、91%、79%、95%、0.94;89%、94%、82%、97%、0.96;92%、97%、86%、98%、0.97。结论:超声诊断DLM是可行和可靠的。应用超声测量膝关节外侧半月板前角、体部和后角的夹角角度诊断DLM的诊断效能明显优于其他超声测量参数,其灵敏度和特异度接近MRI。因此,超声可作为初步诊断DLM的可靠方法。

Objective:Based on the anatomical differences between discoid lateral meniscus(DLM)and normal lateral meniscus(NLM),this study aims to setting up the ultrasound examination parameters to distinguish DLM and NLM and explore the diagnostic value of these parameters on DLM.Methods:According to the inclusion,exclusion and matching criteria,66 DLM patients(DLM group)and 132 NLM patients with other knee joint diseases(NLM group),hospitalized from October 2019 to June 2020,were included in this study.There were 18 males and 48 females in the DLM group,ranging in age from 3 to 60 years old,with a mean of(36.9±12.1)years old;36 males and 96 females in the NLM group,ranging in age from 3 to 60 years old,with a mean of(40.0±12.2)years old.Philips high frequency(3.0 to 12.0 MHz)linear array ultrasound probe was used to examine the lateral meniscus of all patients in two groups.Nine parameters including the thickness,width and the included angle of the anterior angle,body and posterior angle respectively in the lateral meniscus were measured.The included angke is formed by the chords of the upper and lower curved surfaces of the meniscus at the free edge.The independent t test was used to analyze the difference of the measured parameters between the DLM group and the NLM group.The receiver operating characteristic(ROC)curve was used to evaluate the cut-off value of each parameter for diagnosing DLM and the corresponding sensitivity,specificity,positive predictive value,negative predictive value,and area under the ROC curve(AUC).Results:The above 9 ultrasound measurement parameters between the DLM group and the NLM group had significant statistical differences(P<0.001).The ROC curve analysis method evaluated the cut-off value and diagnostic capabilities of these nine ultrasound parameters for DLM.The results showed that the cut-off value of the included angle of anterior part,body and posterior part were 25.85°,24.85°and 29.15°,respectively;and the sensitivity,specificity,negative predictive value,positive predictive value and AUC were significantly higher than other parameters,which were 88%,91%,79%,95%,0.94;89%,94%,82%,97%,0.96;92%,97%,86%,98%,0.97,respectively.Conclusion:Ultrasound diagnosis of DLM is feasible and reliable.The diagnostic ability of the included angle of the anterior part,body and posterior part in the lateral meniscus measured by ultrasound to diagnose DLM are significantly better than other ultrasound measurement parameters,and the sensitivity and specificity of those parameters are close to MRI.Therefore,ultrasound can be used as a reliable method for preliminary diagnosis of DLM.