University of Toronto, Toronto, ON, Canada.
Foot Ankle Int. 2013 Dec;34(12):1669-76. doi: 10.1177/1071100713500489. Epub 2013 Aug 21.
The sagittal relationship of the talus to the tibial shaft can prove invaluable to the orthopedist in understanding and effectively treating ankle pathologies such as ligamentous laxity and ankle arthritis. Any useful radiographic analysis tool to assess the lateral position of the talus must be employable reliably in the clinical setting. Previously published measurements to assess the lateral translational relationship of the talus relative to the tibial axis may not be available in the clinical setting or may be subject to significant inaccuracies. We have defined a sagittal talar position measurement (lateral talar station; LTS), which we postulated could be used reproducibly on clinical radiographs by the orthopedist to define the position of the talus as it relates to the anatomic tibial axis. In addition, we defined the normal range of the LTS measurement.
A retrospective cohort of patients (121 ankles, 104 patients) who presented to our clinic with foot pain between 2005 and 2011 was evaluated for inclusion in the study. Exclusion criteria included patients with ankle trauma, instability, prior ankle surgery, or radiographic evidence of ankle osteoarthrosis. The final cohort consisted of 82 ankles. The LTS was measured digitally for each subject on weight-bearing lateral ankle radiographs by 3 observers. The mean LTS and standard deviation was determined for the entire cohort. In addition, as a means of validating our methodology, we performed an assessment of interobserver and intraobserver reliability in terms of the LTS measurements.
The LTS measurements for the entire cohort fit a Gaussian distribution with a mean of 1.17 mm (SD = 0.9893 mm). Interobserver intraclass coefficients for 2 observers (medical student and radiologist) and intraobserver intraclass coefficients for 1 reader (orthopaedic surgeon) indicated excellent reliability, being above 0.9.
The LTS was a reliable measure that could be used on weight-bearing lateral ankle radiographs to define sagittal position of the talus in a clinical setting. The normal distribution for the LTS was described in our study population.
Level IV, case series.
距骨与胫骨骨干的矢状关系对于理解和有效治疗踝关节韧带松弛和关节炎等踝关节疾病的骨科医生来说非常有价值。任何用于评估距骨外侧位置的有用影像学分析工具都必须能够在临床环境中可靠地使用。以前发表的评估距骨相对于胫骨轴的横向平移关系的测量方法可能无法在临床环境中使用，或者可能存在很大的误差。我们定义了一个距骨矢状位置测量值（外侧距骨站；LTS），我们推测骨科医生可以在临床 X 光片上重复使用该测量值来定义距骨相对于解剖胫骨轴的位置。此外，我们还定义了 LTS 测量值的正常范围。
对 2005 年至 2011 年间因足部疼痛就诊于我们诊所的患者（104 例患者，121 个踝关节）进行回顾性队列研究，评估其是否符合纳入标准。排除标准包括踝关节创伤、不稳定、既往踝关节手术或 X 线证据显示有踝关节骨关节炎的患者。最终纳入 82 个踝关节。3 位观察者对每位患者负重侧踝关节 X 线片上的 LTS 进行数字测量。确定整个队列的 LTS 平均值和标准差。此外，作为验证我们方法的一种手段，我们还评估了 LTS 测量值的观察者间和观察者内可靠性。
整个队列的 LTS 测量值符合高斯分布，平均值为 1.17 毫米（SD=0.9893 毫米）。2 位观察者（医学生和放射科医生）的观察者间组内相关系数和 1 位读者（骨科医生）的观察者内组内相关系数均表示具有极好的可靠性，均大于 0.9。
LTS 是一种可靠的测量方法，可用于负重侧踝关节 X 线片，以在临床环境中定义距骨的矢状位置。本研究人群中描述了 LTS 的正态分布。
IV 级，病例系列。
