后角肥大型盘状半月板的动态MRI研究

目的 通过后角肥大型盘状半月板的动态分析,探讨后角肥大型盘状半月板的形成原因.资料与方法 总共40例患者分为两组,一组为后角肥大型盘状半月板,另一组为随即选取的板型或凹面镜型盘状半月板.首先对所有患者进行膝关节伸直位MR扫描,再令患者适当活动膝关节,然后膝关节维持在屈曲30°位进入磁体扫描.分别观察前后两次扫描半月板的形态变化,并测量半月板后缘的最大厚度.结果 20例后角肥大型盘状半月板患者中,有9例在活动后半月板发生了明显的形态变化,最大厚度明显降低,转变为板型或凹面镜型盘状半月板.而板型或凹面镜型盘状半月板没有发生明显形态变化.两组病例在伸直位向屈曲位变化时半月板后缘的最大厚度的改变量间差异有统计学意义(P<0.01).结论 后角肥大型盘状半月板可能是板型或凹面镜型盘状半月板变形后的一种表现.

Dynamic MRI Study of the Gross Posterior Horn Typed Discoid Meniscus

Objective To analyze the reasons that the gross posterior horn typed discoid meniscus formed by the study of the dynamic MRI.Materials and Methods 40 patients were divided into two groups including twenty patients with gross posterior horn typed discoid meniscus and twenty patients with slab typed or biconcave typed discoid meniscus.MRI was performed in the positions of both knee extension and knee flexion at 30 degree.The changes of the meniscus were observed and the maximal thickness of the post edge of the meniscus was measured.Results In twenty patients with gross posterior horn typed discoid meniscus,changes of the meniscus were found with the maximal thickness of the post edge of the meniscus decreased.No obvious change was identified in another group.There was a significant difference in the change of the meniscus from knee extension to knee flexion between two groups(P<0.01).Conclusion The gross posterior horn typed discoid meniscus might form from slab typed or biconcave typed discoid meniscus.