Background:Detection of meniscal ramp lesions concomitant with anterior cruciate ligament (ACL) injury using conventional magnetic resonance imaging (MRI) has low sensitivity, and these lesions are currently difficult to diagnose preoperatively.Purpose/Hypothesis:The purpose of this study was to assess the accuracy of MRI in detecting the presence of meniscal ramp lesions in the 120° flexed-knee position compared with that in the near–extended-knee position. It was hypothesized that the diagnostic performance of MRI in the 120° flexed-knee position would be better than that in the extended-knee position.Study Design:Cohort study (Diagnosis); Level of evidence, 2.Methods:This retrospective study of prospectively collected data between February 2019 and January 2024 included 154 consecutive patients undergoing ACL reconstruction. All patients underwent 3-T MRI examination in the near extended- and 120° flexed-knee positions preoperatively. The presence and Thaunat classification of ramp lesions were separately detected on each MRI scan and confirmed via arthroscopy during ACL reconstruction. Diagnostic sensitivity, specificity, and conditional relative odds ratios for detecting ramp lesions and the classification accuracy were compared between 2 MRI modalities. The accuracies of these MRI scans in acute and chronic cases were also evaluated.Results:This study included 154 patients (79 male and 75 female; mean age, 29.0 ± 14.2 years). A total of 62 ramp lesions (40.3%) were observed on arthroscopy. The sensitivity and specificity of MRI in near extension were 69.4% and 77.2%, respectively, and those in flexion were 91.9% and 94.6%, respectively, with significant superiority in MRI at knee flexion ( P = .003 and P < .001, respectively). The conditional relative odds ratio between the MRI examinations at these 2 positions was 10.3 (95% CI, 4.82-21.8). The classification accuracy of MRI in flexion was significantly higher than that of MRI in near extension (accuracy, 49 vs 11; P < .001). The diagnostic accuracy of MRI in the 120° flexed-knee position was significantly higher than that in the near–extended-knee position in the acute cases ( P < .05); however, no significant differences were observed in the chronic cases.Conclusion:The diagnostic accuracy of MRI in the 120° flexed-knee position for detecting and classifying meniscal ramp lesions was superior to that of MRI in the near–extended-knee position.

中文翻译：

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120° 屈膝位置磁共振成像检测和分类半月板斜坡病变的诊断准确性


背景： 使用常规磁共振成像 （MRI） 检测伴前交叉韧带 （ACL） 损伤的半月板斜坡病变敏感性低，这些病变目前难以术前诊断。目的/假设： 本研究的目的是评估 MRI 检测 120° 屈膝位置与近伸展膝关节位置相比半月板斜坡病变存在的准确性。据推测，MRI 在 120° 屈膝位置的诊断性能会优于在伸展膝关节位置的诊断性能。研究设计： 队列研究 （诊断）;证据水平， 2.方法： 这项回顾性研究对 2019年2月至 2024年1月期间前瞻性收集的数据进行了研究，包括 154 例连续接受 ACL 重建的患者。所有患者术前均在近伸展和 120° 屈膝位置接受 3-T MRI 检查。在每次 MRI 扫描中分别检测斜坡病变的存在和 Thaunat 分类，并在 ACL 重建期间通过关节镜确认。比较 2 种 MRI 模式之间检测斜坡病变的诊断敏感性、特异性和条件相对比值比以及分类准确性。还评估了这些 MRI 扫描在急性和慢性病例中的准确性。结果： 本研究包括 154 例患者 （男性 79 例，女性 75 例;平均年龄 29.0 ± 14.2 岁）。关节镜检查共观察到 62 个 ramp 病灶 （40.3%）。MRI 在近伸展时的敏感性和特异性分别为 69.4% 和 77.2%，屈曲时分别为 91.9% 和 94.6%，膝关节屈曲时 MRI 的敏感性和特异性显著优胜 （分别为 P = .003 和 P < .001）。 这 2 个位置的 MRI 检查之间的条件相对比值比为 10.3 （95% CI，4.82-21.8）。MRI 在屈曲时的分类准确性显著高于 MRI 在近伸展时的分类准确性（准确性，49 对 11;P < .001）.急性病例 120° 屈膝位 MRI 诊断准确性显著高于近伸展膝关节位置 （ P < .05）;然而，在慢性病例中未观察到显着差异。结论： 120° 屈膝位置 MRI 检测和分类半月板斜坡病变的诊断准确性优于近伸展膝关节位置的 MRI。