Accuracy of Magnetic Resonance Imaging in Identifying the Configuration of Meniscus Tears

Background: Knowing the configuration of a meniscus tear is important for planning the treatment protocol. Objectives: The aim of this study was to evaluate the accuracy of magnetic resonance imaging (MRI) in determining meniscus tear configurations through a retrospective assessment of MR images from patients who underwent arthroscopy for an initial diagnosis of meniscus tear. Patients and Methods: A retrospective comparison was made between MRI findings and arthroscopic results of patients to whom arthroscopy was applied by a single experienced surgeon for an initial diagnosis of meniscus tear. The MR images were taken with a 1.5 Tesla unit. The meniscus tears were classified in subgroups as horizontal, longitudinal, radial, flap, bucket handle, and complex. Results: In 60 knees of 57 patients, 32 lateral meniscus and 48 medial meniscus lesions were identified by MRI. Of these tears, 33 were complex, 15 longitudinal, 13 radial, 11 bucket handle, 5 flap, and 3 horizontal. For the total 80 meniscus tears, MRI gave the same diagnosis as arthroscopy in 60 (75%). Longitudinal and flap tears had low sensitivity (79% in medial and 50% in lateral meniscus for longitudinal tears; 33% to 57%, respectively, for flap tears) but high specificity. Conclusion: MRI is an important tool in the imaging of meniscus tears, but for longitudinal and flap tear configurations that require arthroscopy, MRI diagnostics are especially insensitive. Nonetheless, MRI evaluation paired with good clinical evaluation can be considered useful when planning a surgical protocol and when defining the postoperative prognosis.