屈曲90°位核磁共振诊断陈旧性后交叉韧带损伤的意义（开放获取）

Significance of MRI examination at 90° knee flexion for diagnosis of old posterior cruciate ligament rupture

摘要:

[目的]评价膝关节屈曲 90°位核磁共振影像检查（magnetic resonance imaging, MRI）对陈旧性后交叉韧带（posterior cruciate ligament, PCL） 损伤的诊断意义。[方法] 选取本院 2018 年 1 月—2023 年 12 月收治的 32 例膝关节单侧 PCL 损伤患者进行临床和影像资料回顾性分析。MRI 图像由 2 名放射科医生进行评估，并达成共识。全部患者都通过抽屉试验筛查出有存在 PCL 损伤，并均通过膝关节镜手术确诊。所有患者均接受伸直位、膝关节屈曲 90°位 MRI 检查，将检查结果与关节镜手术结果进行比较和分析。[结果] 屈曲位 MRI 测量结果得出，正常 PCL 平均长度 （43.6±1.2） mm，宽度 （7.5±0.8） mm，矢状角 （77.9±1.2）°；损伤 PCL 平均长度 （46.8±2.5） mm，宽度 （9.4±0.9） mm，矢状角 （74.3±1.3）°。而伸直位 MRI 测量损伤 PCL 平均长度（37.3±1.1）mm，宽度（10.1±0.9）mm，矢状角（70.2±1.4）°。PCL 损伤 MRI 检查伸直位与损伤屈曲位在宽度、长度及角度测量值指标比较差异均有统计学意义 （P＜0.001）。伸膝位是否损伤的 PCL 长度变化率为 3.6%，而屈曲 90°位否损伤的 PCL 长度 7.3%。健侧伸膝位与屈膝位 PCL 长度变化率为 21.1%，伤侧伸膝位与屈膝位 PCL 长度变化率为 25.5%。[结论]采用屈曲位 MRI 检查可显著扩大 PCL 长度的变化率，有利于提升陈旧性 PCL 损伤诊断的准确性。

Abstract:

[Objective] To evaluate the significance of magnetic resonance imaging (MRI) examination at 90° knee flexion for the diagnosis of old posterior cruciate ligament (PCL) rupture. [Methods] A retrospective study was conducted on 32 patients who had unilateral PCL tear treated surgically in our hospital from January 2018 to December 2023. All patients were screened for PCL injury by drawer test, underwent MRI examination in extension position and 90° knee flexion, and got old PCL rupture confirmed by arthroscopic surgery. The MRI images were evaluated by two radiologists and a consensus was reached. The MRI measurments were compared and analyzed with those of arthroscopic surgery. [Results] The MRI at 90° knee flexion showed that the normal PCL was of (43.6±1.2) mm in length, (7.5±0.8) in mm width and (77.9±1.2)° in sagittal angle, while the old torn PCL was of (46.8±2.5) mm in length, (9.4±0.9) mm in width and (74.3± 1.3)° in sagittal angle. By comparison, the MRI at knee extension measured the old torn PCL (37.3±1.1) mm in length, (10.1±0.9) mm in width and (70.2±1.4)° in sagittal angle. There were statistical significant differences in the old torn PCL in width, length and sagittal angle between the knee extension and 90° knee flexion position (P＜0.001). The length variation ratio between the normal PCL and torn PCL increased from 3.6% at knee extension position to 7.3% at 90° knee flexion, while the length variation ratio between the knee extension and 90° knee flexion was 21.1% for normal PCL, while 25.5% for the old torn PCL. [Conclusion] MRI examination at 90° knee flexion can significantly expand the length variation ratio of the PCL, which is conducive to improving the accuracy of diagnosis of old PCL injury.