PURPOSE The purpose of this study was to compare the reliability and accuracy of existing computed tomography (CT) methods for measuring the distal tibiofibular syndesmosis in uninjured, paired cadaveric specimens and in simulated malreduction models. It was hypothesized that a repeatable set of measurements exists to accurately and quantitatively describe the typical forms of syndesmotic malreduction using contralateral ankle comparison. METHODS Twelve cadaveric lower-leg specimen pairs were imaged with CT to generate models for this study. Thirty-five measurements were performed on each native model. Next, four distinct fibular malreductions were produced via digital simulation and all measurements were repeated for each state: (1) 2-mm lateral translation; (2) 2-mm posterior translation; (3) 7-degree external rotation; (4) the previous three states combined. The modified standardized response mean (mSRM) was calculated for each measurement. To assess rater reliability and side-to-side agreements of the native state measurements, intraclass correlation coefficients (ICC) and Pearson correlation coefficients (PCC) were calculated, respectively. RESULTS The most responsive measurements for detecting isolated malreduction were the Leporjärvi clear space for lateral translation, the Nault anterior tibiofibular distance for posterior translation, and the Nault talar dome angle for external rotation of the fibula. These measurements demonstrated fair to excellent inter-rater ICCs (0.64-0.76) and variable side-to-side PCCs (0.14-0.47). CONCLUSIONS The most reliable method to assess the syndesmosis on CT was to compare side-to-side differences using three distinct measurements, one for each type of fibular malreduction, allowing assessment of the magnitude and directionality of syndesmosis malreduction. Reliable evaluation is essential for assessing subtle syndesmosis injuries, malreduction and surgical planning.

中文翻译：

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定义脚踝下颌联合畸形减少的三个最敏感和特定的CT测量。

目的本研究的目的是比较现有的计算机断层扫描（CT）方法在未受伤，成对的尸体标本和模拟的减少畸形模型中测量远端胫腓联合的可靠性和准确性。假设存在一组可重复使用的测量方法，以使用对侧踝关节比较来准确，定量地描述典型的下颌联合脱瘤的典型形式。方法用CT对十二具尸体小腿标本对进行成像，以生成本研究的模型。在每个本机模型上进行了35次测量。接下来，通过数字模拟产生四个明显的腓骨畸形，并针对每种状态重复进行所有测量：（1）2 mm横向平移；（2）2毫米后平移；（3）7度外旋；（4）前三个州合并。为每次测量计算修改后的标准化响应平均值（mSRM）。为了评估评估者的可靠性和本机状态测量的左右一致，分别计算了组内相关系数（ICC）和皮尔逊相关系数（PCC）。结果对孤立性异常复位的反应最灵敏的测量是Leporjärvi间隙进行侧移，Nault前胫腓距用于后移以及Nault距骨穹顶角用于腓骨外旋。这些测量结果表明，评估者之间的ICC（0.64-0.76）相当，而侧面PCC（0.14-0.47）则各不相同。结论评估CT上病变的最可靠方法是使用三种不同的测量方法来比较侧向差异，一种针对每种类型的腓骨畸形，从而可以评估该病变的程度和方向。可靠的评估对于评估细微的联合症损伤，复位不良和手术计划至关重要。