Department of Orthopaedics and Rehabilitation, Larner College of Medicine at the University of Vermont, Burlington, VT; and.
Department of Biomedical Statistics; University of Vermont, Burlington, VT.
J Orthop Trauma. 2022 Jan 1;36(1):e12-e17. doi: 10.1097/BOT.0000000000002151.
To evaluate the accuracy and reliability of a novel fluoroscopic technique for assessing tibial rotation and compare it with a previously described fluoroscopic method.
A multiplanar circular ring external fixator was secured to the tibial diaphysis of 5 cadaveric lower extremity specimens. Using deformity correction software, the frame and tibia were programed to randomly rotate 5, 10, 15, 20, 25, and 30 degrees of internal and external rotation. After each rotation, 2 blinded, independent observers measured the degree of tibial rotation using 2 different fluoroscopic methods: the previously described "mortise" method and the novel "intermalleolar" method. A total of 65 measurements were made by each observer. Accuracy and interobserver reliability were calculated.
Both intermalleolar and mortise methods had a mean absolute rotational difference from the true torsion of 3 degrees (standard error 1; range, 0-10 degrees intermalleolar vs. 0-18 degrees mortise). We found that 98.5% (128/130) of measurements using the intermalleolar method were less than 10 degrees from the true rotation compared with 93.8% (122/130) using the mortise method. Both the intermalleolar and the mortise methods had excellent interobserver reliability (intraclass correlation coefficient 0.99 and 0.96, respectively).
Measuring tibial rotation fluoroscopically using the intermalleolar method is both accurate and reliable. Compared with the previously described mortise method, it has similar accuracy and provides a value that approximates the true tibial rotation. Also, it can be used reliably and effectively intraoperatively to identify tibial malrotation and assist in intraoperative rotational corrections.
评估一种新的评估胫骨旋转的透视技术的准确性和可靠性，并与之前描述的透视方法进行比较。
将多平面圆形环外固定器固定在 5 个尸体下肢标本的胫骨骨干上。使用畸形矫正软件，将框架和胫骨编程为随机旋转 5、10、15、20、25 和 30 度的内旋和外旋。每次旋转后，2 名独立的盲法观察者使用 2 种不同的透视方法（之前描述的“榫眼”方法和新的“踝间”方法）测量胫骨旋转的程度。每位观察者共进行了 65 次测量。计算了准确性和观察者间可靠性。
踝间和榫眼方法的平均绝对旋转差异与真实扭转度均为 3 度（标准误差 1；范围，踝间 0-10 度与榫眼 0-18 度）。我们发现，与使用榫眼方法相比，98.5%（128/130）的踝间方法测量值小于 10 度，而使用榫眼方法的测量值为 93.8%（122/130）。踝间和榫眼方法均具有极好的观察者间可靠性（组内相关系数分别为 0.99 和 0.96）。
使用踝间方法透视测量胫骨旋转既准确又可靠。与之前描述的榫眼方法相比，它具有相似的准确性，并且提供了接近真实胫骨旋转的数值。此外，它可以在手术中可靠有效地用于识别胫骨旋转不良，并协助术中旋转矫正。
