Scrutinizing the cut-off for "pathological" meniscal body extrusion on knee MRI

Journal article

Publication Details

Author(s): Svensson F, Felson DT, Turkiewicz A, Guermazi A, Roemer F, Neuman P, Englund M
Journal: European Radiology
Publication year: 2019
Volume: 29
Journal issue: 5
Pages range: 2616-2623
ISSN: 0938-7994


ObjectivesMedial meniscal body extrusion 3mm on MRI is often considered pathologic. The aims of this study were to (1) assess the adequacy of 3mm as cut-off for pathological extrusion and (2) find an optimal cut-off for meniscal extrusion cross-sectionally associated with radiographic knee osteoarthritis, bone marrow lesions (BMLs), and cartilage damage.MethodsNine hundred fifty-eight persons, aged 50-90years from Framingham, MA, USA, had readable 1.5T MRI scans of the right knee for meniscal body extrusion (measured in mm). BMLs and cartilage damage were read using the whole organ magnetic resonance imaging score (WORMS). Knee X-rays were read according to the Kellgren and Lawrence (KL) scale. We evaluated the performance of the 3-mm cut-off with respect to the three outcomes and estimated a new cut-off maximizing the sum of sensitivity and specificity.ResultsThe study persons had mean age of 62.2years, 57.0% were women and the mean body mass index was 28.5kg/m(2). Knees with radiographic osteoarthritis, BMLs, and cartilage damage had overall more meniscal extrusion than knees without. The 3-mm cut-off had moderate sensitivity and low specificity for all three outcomes (sensitivity between 0.68 [95% CI 0.63-0.73] and 0.81 [0.73-0.87], specificity between 0.49 [0.45-0.52] and 0.54 [0.49-0.58]). Using 4mm maximized the sum of sensitivity and specificity and improved the percentage of correctly classified subjects (from between 54 and 61% to between 64 and 79%).ConclusionsThe 4-mm cut-off may be used as an alternative cut-off for denoting pathological meniscal extrusion.Key Points center dot Medial meniscal body extrusion is strongly associated with dot The 3-mm cut-off for medial meniscal body extrusion has high sensitivity but low specificity with respect to bone marrow lesions, cartilage damage, and radiographic dot The 4-mm cut-off maximizes the sensitivity and specificity with respect to all three osteoarthritis features.

FAU Authors / FAU Editors

Roemer, Frank Prof. Dr.
Radiologisches Institut

External institutions with authors

Boston University
Lund University / Lunds universitet

How to cite

Svensson, F., Felson, D.T., Turkiewicz, A., Guermazi, A., Roemer, F., Neuman, P., & Englund, M. (2019). Scrutinizing the cut-off for "pathological" meniscal body extrusion on knee MRI. European Radiology, 29(5), 2616-2623.

Svensson, F., et al. "Scrutinizing the cut-off for "pathological" meniscal body extrusion on knee MRI." European Radiology 29.5 (2019): 2616-2623.


Last updated on 2019-16-04 at 14:23