MRI Diagnosis of the Tear Pattern of Menisci

반월상 연골판 파열 양상의 자기공명영상 진단

In the diagnosis of the meniscal tear of the knee, the high accuracy of the MRI diagnosis is well-known, but the accuracy of the MRI in the diagnosis of the very pattern of the tear of menisci is not well-established. The purpose of this study is to give some informations to consider in the diagnosis and therapeutic planning of torn menisci. The authors performed a retrospective study comparing the MRI and arthroscopic findings of 141 knees which had undergone arthroscopic surgery from Mar. 1997 to Mar. 1998. The results are as follows. In the diagnosis of tear of the menisci, MRI had sensitivity of 91%, specificity of 96%, accuracy of 95%. The mismatch of the tear patterns of the menisci between MRI and arthroscopic findings was identified in 59%, especially high in flap tear(100%), complex tear(84%), peripheral tear(55%). In conclusion, MRI is very accurate in the diagnosis of the tear of menisci, but the tear patterns of the menisci cannot be accurately determined by MRI. In the cases of flap tears, complex tears and peripheral tears, it is more difficult to determine the tear patterns of the menisci by MRI. False-negative rate of MRI was especially high(44%) in the peripheral tear type. So, other clinical correlations should be made in determination of the presence of the tear in the diagnosis of peripheral tear of the menisci.