Department of Orthopaedic Surgery, Okayama University Hospital, 2-5-1 Shikatacho, Kitaku, Okayama, 700-8558, Japan.
Department of Orthopaedic Surgery, Ako Central Hospital, 52-6 Sohmon-cho, Ako, Hyogo, 678-0241, Japan.
Knee Surg Sports Traumatol Arthrosc. 2022 Nov;30(11):3726-3732. doi: 10.1007/s00167-022-06983-8. Epub 2022 May 4.
This study aimed to evaluate changes in the cleft width, defined as the distance between the lateral edge of the medial tibial plateau and that of the medial meniscus (MM) posterior root, using open magnetic resonance imaging (MRI) in patients with MM posterior root tear (MMPRT).
This study included 25 patients (20 women and 5 men; mean age: 65.2 years) who were diagnosed with MMPRT and underwent pullout repair. Upon coronal imaging, the cleft width was evaluated at the 10° and 90° flexed knee positions. The difference in the cleft width (defined as the cleft width at 90° minus the cleft width at 10°) was also calculated. Upon sagittal imaging, the MM posterior extrusion (MMPE) at 90° was also evaluated. Separate univariate linear regression models were used to determine the association between the time from injury to MRI and radiographic measurements.
The mean cleft width at 10° and 90° was 4.9 ± 2.6 mm and 7.4 ± 3.7 mm, respectively; the mean difference in cleft width was 2.5 ± 1.5 mm, and the mean MMPE at 90° was 3.7 ± 1.3 mm. There was a significant difference in cleft width at 10° and 90° (p < 0.001). The time from injury to MRI was significantly associated with the cleft width at 10° (R = 0.42; p = 0.023), cleft width at 90° (R = 0.59; p = 0.002), the difference in the cleft width (R = 0.62; p = 0.008), and MMPE at 90° (R = 0.53; p = 0.008).
This study demonstrates that the cleft width is significantly larger during knee flexion than during knee extension. Increased cleft width during knee flexion ("graben" sign) may help diagnose MMPRT, especially in cases where the cleft sign is unclear during knee extension.
III.
本研究旨在通过开放磁共振成像（MRI）评估半月板后根撕裂（MMPRT）患者的内侧胫骨平台外侧边缘与内侧半月板（MM）后根之间的裂宽度（定义为后裂宽度）的变化。
本研究纳入了 25 名（20 名女性，5 名男性；平均年龄：65.2 岁）被诊断为 MMPRT 并接受了抽出修复术的患者。在冠状成像上，评估膝关节 10°和 90°屈曲时的裂宽度。还计算了裂宽度的差异（定义为 90°时的裂宽度减去 10°时的裂宽度）。在矢状成像上，评估 90°时的 MM 后突（MMPE）。使用单独的单变量线性回归模型来确定损伤至 MRI 和影像学测量之间的时间与放射学测量之间的相关性。
10°和 90°时的平均裂宽度分别为 4.9±2.6mm 和 7.4±3.7mm；裂宽度的平均差异为 2.5±1.5mm，90°时的 MMPE 平均为 3.7±1.3mm。10°和 90°时的裂宽度存在显著差异（p<0.001）。损伤至 MRI 的时间与 10°时的裂宽度（R=0.42；p=0.023）、90°时的裂宽度（R=0.59；p=0.002）、裂宽度的差异（R=0.62；p=0.008）和 90°时的 MMPE（R=0.53；p=0.008）显著相关。
本研究表明，膝关节屈曲时的裂宽度明显大于膝关节伸展时的裂宽度。膝关节屈曲时裂宽度的增加（“graben”征）可能有助于诊断 MMPRT，尤其是在膝关节伸展时裂征不明显的情况下。
III。
