Department of Biomedical, Surgical and Dental Sciences, Università degli Studi di Milano, Via della Commenda, 10, 20122, Milan, Italy.
U.O.C. 1° Clinica Ortopedica, ASST Gaetano Pini-CTO, Piazza Cardinal Ferrari 1, 20122, Milan, Italy.
Knee Surg Sports Traumatol Arthrosc. 2023 Nov;31(11):5005-5011. doi: 10.1007/s00167-023-07525-6. Epub 2023 Aug 31.
This study's goal is to propose a straightforward classification system based on the MEI (Meniscal Extrusion Index), a measure of meniscal extrusion, that relates to various meniscal lesion patterns and has clinical and biomechanical significance. The study's secondary goal is to determine whether the standard 3 mm meniscal extrusion parameter still has value by correlating the MEI with it.
1350 knee MRIs that were performed over the course of 2 years made up the study cohort. Following the application of inclusion and exclusion criteria, 200 of those patients were qualified to participate in the study. All the measurements examined for this study underwent an interobserver reliability test.
In the 1350 MRIs that were examined for this study, meniscal extrusion of any grade was present 18.9% of the time. The use of the MEI revealed three groups of patients: those with a MEI < 20%, who are likely para-physiological; those with a MEY between 20% and 40%, who are in a grey area; and those with a MEY > 40%, who have lesions that are impairing the proper meniscal function. According to the authors' findings, the percentage of meniscal extrusion did not correlate with the finite number (3 mm), making the 3 mm parameter an unreliable evaluation method.
This study is clinically relevant, because it proposes a simple and reproducible classification of meniscal extrusion that may aid in evaluating the severity of an extrusion and help in the diagnosis of lesions that might be difficult to identify on MRI.
Level IV.
本研究旨在提出一种基于半月板挤出指数（MEI）的简单分类系统，该指数与各种半月板病变模式相关，具有临床和生物力学意义。本研究的次要目的是通过将 MEI 与标准 3mm 半月板挤出参数相关联，确定该参数是否仍具有价值。
该研究队列由 2 年内进行的 1350 次膝关节 MRI 组成。在应用纳入和排除标准后，有 200 名符合条件的患者参与了本研究。本研究中检查的所有测量均进行了观察者间可靠性测试。
在本研究中检查的 1350 份 MRI 中，任何等级的半月板挤出的发生率为 18.9%。使用 MEI 显示了三组患者：MEI<20%的患者可能处于生理边缘；MEI 在 20%至 40%之间的患者处于灰色区域；MEI>40%的患者有损伤，会影响半月板的正常功能。根据作者的发现，半月板挤出的百分比与有限的数值（3mm）不相关，这使得 3mm 参数成为一种不可靠的评估方法。
本研究具有临床相关性，因为它提出了一种简单且可重复的半月板挤出分类方法，可能有助于评估挤出的严重程度，并有助于诊断在 MRI 上难以识别的病变。
IV 级。
