Department of Orthopaedic Surgery, Sapporo Medical University School of Medicine, Sapporo, Hokkaido, Japan.
Graduate School of Health Science, Sapporo Medical University, Sapporo, Hokkaido, Japan.
Foot Ankle Int. 2021 Aug;42(8):1074-1080. doi: 10.1177/1071100721996714. Epub 2021 Mar 26.
Manual evaluation is an important method for assessing ankle instability, but it is not quantitative. Capacitance-type sensors can be used to measure the distance on the basis of the capacitance value. We applied the sensor to the noninvasive device for measuring ankle instability and showed its utility.
First, 5 ankles embalmed by Thiel's method were used in an experiment using a cadaver. The capacitance-type sensor was fixed alongside the anterior talofibular ligament (ATFL) of a specially made brace, and the anterior drawer test was performed. The test had been performed for the intact ankle, with the ATFL transected and with both the ATFL and calcaneofibular ligament (CFL) transected. The anterior drawer distance was calculated by the sensor. Intra- and interinvestigator reliability were also analyzed.Next, as a clinical study, a brace with a sensor was fitted to 22 ankles of 20 patients with a history of ankle sprain. An anterior drawer test at a load of 150 N was conducted using a Telos stress device. The anterior drawer distances measured by the sensor and based on radiographic images were then compared.
The mean anterior drawer distances were 3.7 ± 1.0 mm for the intact cadavers, 6.1 ± 1.6 mm with the ATFL transected ( < .001), and 7.9 ± 1.8 mm with the ATFL and CFL transected ( < .001). The intrainvestigator intraclass correlation coefficients (ICCs) were 0.862 to 0.939, and the interinvestigator ICC was 0.815. In the experiments on patients, the mean anterior drawer distance measured by the sensor was 2.9 ± 0.9 mm, and it was 2.7 ± 0.9 mm for the radiographic images. The correlation coefficient between the sensor and the radiographic images was 0.843.
We quantitatively evaluated anterior drawer laxity using a capacitance-type sensor and found it had high reproducibility and strongly correlated with stress radiography measurements in patients with ankle instability. Capacitance-type sensors can be used for the safe, simple, and accurate evaluation of ankle instability.
手动评估是评估踝关节不稳定的重要方法，但它不是定量的。电容式传感器可以基于电容值来测量距离。我们将传感器应用于测量踝关节不稳定的非侵入性设备，并展示了其实用性。
首先，我们在一项使用尸体的实验中使用了 5 只经过 Thiel 法防腐处理的踝关节。将电容式传感器固定在特制支具的前距腓韧带（ATFL）旁边，进行前抽屉试验。试验已在完整踝关节、ATFL 切断和 ATFL 和跟腓韧带（CFL）切断的情况下进行。传感器计算前抽屉距离。还分析了内部和外部观察者的可靠性。
接下来，作为一项临床研究，将带有传感器的支具适配于 20 例有踝关节扭伤病史的患者的 22 个踝关节。使用 Telos 应力装置在 150 N 的负荷下进行前抽屉试验。然后比较传感器和基于放射图像测量的前抽屉距离。
完整尸体的平均前抽屉距离为 3.7 ± 1.0 毫米，ATFL 切断时为 6.1 ± 1.6 毫米（<.001），ATFL 和 CFL 切断时为 7.9 ± 1.8 毫米（<.001）。内部观察者的组内 ICC 为 0.862 至 0.939，外部观察者的 ICC 为 0.815。在患者的实验中，传感器测量的平均前抽屉距离为 2.9 ± 0.9 毫米，放射图像为 2.7 ± 0.9 毫米。传感器和放射图像之间的相关系数为 0.843。
我们使用电容式传感器定量评估了前抽屉松弛度，发现其具有高重复性，与踝关节不稳定患者的应力放射照相测量结果密切相关。电容式传感器可用于安全、简单和准确地评估踝关节不稳定。
