Background: If tibiofibular syndesmotic injury is undetected, chronic instability may lead to persistent pain and osteoarthritis. So far, no reliable diagnostic method has been available. The primary objectives of this study were to determine whether defined lesions of the syndesmosis can be correlated with specific tibiofibular joint displacements caused by external rotational torque and to compare the performance of bilateral external torque computed tomography (BET-CT) and arthroscopy. Secondary objectives included an evaluation of the reliability of CT measurements and the suitability of the healthy contralateral ankle as a reference. Methods: Seven pairs of healthy, cadaveric lower legs were tested and assigned to 2 groups: (1) supination-external rotation (SER) and (2) pronation-external rotation (PER). In the intact state and after each surgical step, an ankle arthroscopy and 3 CT scans were performed. During the scans, the specimens were placed in an external torque device with 2.5, 5.0, and 7.5 Nm of torque applied. Results: The arthroscopic and CT parameters showed significant correlations in all pairwise comparisons. The receiver operating characteristic (ROC) curve analyses yielded the best prediction of syndesmotic instability with the anterior tibiofibular distance on CT, with a sensitivity of 84.1% and a specificity of 95.2% (area under the curve [AUC], 94.8%; 95% confidence interval [CI], 0.916 to 0.979; p < 0.0001) and with the middle tibiofibular distance on arthroscopy, with a sensitivity of 76.2% and specificity of 92.3% (AUC, 91.2%; 95% CI, 0.837 to 0.987; p < 0.0001). Higher torque amounts increased the rate of true-positive results. Conclusions: BET-CT reliably detects experimental syndesmotic rotational instability, compared with the healthy side, with greater sensitivity and similar specificity compared with the arthroscopic lateral hook test. Translation of these experimental findings to clinical practice remains to be established. Level of Evidence: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

中文翻译：

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双侧外部扭矩 CT 在实验性尸体研究中可靠地检测韧带联合病变


背景：如果未发现下胫腓联合损伤，慢性不稳定性可能会导致持续性疼痛和骨关节炎。迄今为止，还没有可靠的诊断方法。本研究的主要目的是确定韧带联合的明确病变是否与外旋转扭矩引起的特定下腓关节位移相关，并比较双侧外扭矩计算机断层扫描 (BET-CT) 和关节镜检查的性能。次要目标包括评估 CT 测量的可靠性以及健康对侧踝关节作为参考的适用性。方法：对七对健康的尸体小腿进行了测试，并将其分为 2 组：(1) 旋后外旋 (SER) 和 (2) 旋前外旋 (PER)。在完整状态下以及每个手术步骤后，进行踝关节镜检查和 3 次 CT 扫描。在扫描过程中，将样本放置在外部扭矩装置中，施加 2.5、5.0 和 7.5 Nm 的扭矩。结果：关节镜和 CT 参数在所有成对比较中均显示出显着相关性。受试者工作特征 (ROC) 曲线分析通过​​ CT 上的前下胫腓距离对下胫腓联合不稳定性进行了最佳预测，敏感性为 84.1%，特异性为 95.2%（曲线下面积 [AUC]，94.8%；95%）置信区间 [CI]，0.916 至 0.979；p < 0.0001）以及关节镜检查中下胫腓距离，敏感性为 76.2%，特异性为 92.3%（AUC，91.2%；95% CI，0.837 至 0.987；p < 0.0001）。较高的扭矩量会增加真阳性结果的发生率。 结论：与健康侧相比，BET-CT 能够可靠地检测实验性韧带联合旋转不稳定性，与关节镜侧钩测试相比，具有更高的敏感性和相似的特异性。将这些实验结果转化为临床实践仍有待确定。证据级别：诊断三级。有关证据级别的完整描述，请参阅作者须知。