Orthopaedic Hospital for Children, Behandlungszentrum Aschau GmbH, Bernauerstr. 18, Aschau i. Chiemgau 83229, Germany; HAWK University of Applied Sciences and Arts, Faculty of Engineering and Health Göttingen, Annastr 25, Göttingen 37075, Germany.
Orthopaedic Hospital for Children, Behandlungszentrum Aschau GmbH, Bernauerstr. 18, Aschau i. Chiemgau 83229, Germany; University of Applied Sciences Technikum Wien, Department of Biomedical, Health & Sports Engineering, Höchstädtpl. 6, Wien 1200, Austria.
Gait Posture. 2024 Mar;109:311-317. doi: 10.1016/j.gaitpost.2024.02.013. Epub 2024 Feb 17.
Leg length discrepancy (LLD) is common in youth and is cause by several conditions. Long leg X-rays is the gold standard technique of measuring LLD. It is highly accurate and reliable compared to clinical method, but expose the subject to radiation. Instrumented Gait Analysis (IGA) serves not only as a means to measure joint kinematics during gait but also as a valuable tool for assessing Leg Length Discrepancy (LLD) while standing.
The purpose of this study was to compare different methods of determining the LLD in paediatric population. We hypothesize that IGA using joint centres is more accurate and precise than the tape measurement.
Thirty-one patients with mean age 12.3 (SD=2.4) years were retrospectively included in the study. Their LLD varied between 0 and 36 mm. Three methods for determining LLD were compared to radiography using Bland-Altman analysis: 1. Tape measurement, 2. IGA, summarizing the distance from the spina iliaca anterior superior to the medial malleolus marker via the medial knee condyle marker. 3. IGA, summarizing distances between ankle, knee, and hip joints centres where the latter is calculated with different equations.
The IGA joints method performed better than the tape measurement or IGA markers method. The equations of Davis calculating the hip joint centre had the highest accuracy with mean difference to radiography of 0.7 mm (SD=6.3). The simple Harrington method resulted in a slightly reduced accuracy but higher precision 0.9 mm (SD=6.2). The Harrington method with leg length as input was less accurate 1.0 mm (SD=6.7), but was still considerably better than the tape measurement 1.8 mm (SD=7.0) or IGA markers method 1.1 mm (SD=11.5).
Determining LLD with IGA using the distances between ankle, knee and hip joints centres is a feasible method that can be applied in clinical practice to calculate LLD.
肢体长度差异（LLD）在青少年中很常见，由多种情况引起。长腿 X 射线是测量 LLD 的金标准技术。与临床方法相比，它高度准确可靠，但会使受试者暴露在辐射下。仪器步态分析（IGA）不仅是测量步态期间关节运动的一种手段，也是评估站立时肢体长度差异（LLD）的有价值工具。
本研究的目的是比较确定儿科人群 LLD 的不同方法。我们假设 IGA 使用关节中心比胶带测量更准确和精确。
回顾性纳入 31 名平均年龄为 12.3 岁（SD=2.4）的患者。他们的 LLD 差异在 0 至 36 毫米之间。使用 Bland-Altman 分析比较了三种确定 LLD 的方法与放射学：1. 胶带测量，2. IGA，通过内侧膝髁标记总结从髂前上棘到内踝标记的距离。3. IGA，总结踝关节、膝关节和髋关节中心之间的距离，其中后者通过不同的方程计算。
IGA 关节方法比胶带测量或 IGA 标记方法表现更好。Davis 计算髋关节中心的方程具有最高的准确性，与放射学的平均差异为 0.7 毫米（SD=6.3）。简单的 Harrington 方法的准确性略低，但精度较高为 0.9 毫米（SD=6.2）。输入腿长的 Harrington 方法准确性较差，为 1.0 毫米（SD=6.7），但仍明显优于胶带测量的 1.8 毫米（SD=7.0）或 IGA 标记方法的 1.1 毫米（SD=11.5）。
使用踝关节、膝关节和髋关节中心之间的距离确定 IGA 的 LLD 是一种可行的方法，可以在临床实践中应用于计算 LLD。
