中文摘要：

目的报道儿童症状性外侧盘状半月板损伤患者前交叉韧带（ACL）在MRI图像上的形态及信号特征。方法自2008年3月至2011年10月经关节镜及核磁共振成像（MRI）证实的儿童症状性外侧盘状半月板损伤的26膝（外侧盘状半月板损伤组）和经MRI证实的儿童外侧盘状半月板且无明显损伤的26膝（对照组）被纳入本研究。应用GE Healthcare Centricity RIS/PACKS系统分别测量两组病例在MRI冠状面及矢状面上下止点宽度及体部宽度。比较两组病例ACL形态及信号变化的特征。结果外侧盘状半月板损伤组冠状面ACL体部宽度明显小于对照组（t=2.865,P〈0.01）;矢状面ACL下止点宽度、体部宽度及冠状面下止点宽度与对照组比较差异无统计学意义。外侧盘状半月板损伤组ACL正常走行及形态发生率明显低于对照组（x2=13.019,P〈0.01）;与对照组比较,外侧盘状半月板损伤组在冠状面（x2=10.035,P〈0.01）及矢状面（x2=6.256,P〈0.01）的ACL异常走行及形态发生率均明显增高。外侧盘状半月板损伤组ACL异常信号发生率也高于对照组（x2=3.900,P〈0.05）。结论与无症状、无损伤的儿童外侧盘状半月板相比,症状性儿童外侧盘状半月板损伤可以引发ACL的MRI影像上的形态异常和信号改变,其发生可能与外侧盘状半月板损伤、移位并挤压ACL有关。

英文摘要：

Objective To discuss the MRI morphology and signal characteristics of the anterior cruciate ligament（ ACL） in children with symptomatic discoid lateral meniscus injuries. Methods From March 2008 to October 2011, confirmed by arthroscopy and MRI,26 knees of the children with symptomatic discoid lateral meniscus injuries,were enrolled into the discoid lateral meniscus injury group（ the injury group）,while 26 knees of the children with intact discoid lateral meniscus confirmed by MRI were enrolled into the control group. GE Healthcare Centricity RIS / PACKS System was used to measure the width and the middle width of the tibial attachment of the ACL on the sagittal and coronal MR images for both groups. The morphologic and signal differences of the ACLs between the two groups were compared. Results On the coronal images,the middle width of ACL in the injury group was significantly smaller than that of the control group（ t = 2. 865,P 0. 01）. The width of the tibial attachment measured on both sagittal and coronal MR images of the ACL and the middle width measured on the sagittal image of the ACL showed no significant differences between the two groups. The normal morphology incidence of the ACL in the injury group was significantly lower than the control group（ x2= 13. 019,P 0. 01）.Compared with the control group,the incidences of abnormal direction and abnormal morphology of ACL on the coronal（ x2= 10. 035,P 0. 01） and sagittal images（ x2= 6. 256,P 0. 01） were significantly higher in the injury group. The abnormal signal incidence of the ACL in the injury group was higher than that of the control group（ x2= 3. 900,P 0. 05）. Conclusion Compared with the intact discoid lateral meniscus,the symptomatic discoid lateral meniscus injury could lead to abnormal morphology and signal changes of the ACL on MR images,which seems to be related to the extrusion caused by the displacement of the discoid lateral meniscus injury.