Background

While it is commonly acknowledged that the combined effect of lower limb orientation and ankle and hindfoot alignment play a fundamental role in ankle arthritis, supramalleolar/lower limb alignment has received less attention in valgus ankle arthritis. The purpose of this study was to analyze the lower limb alignment of patients with valgus ankle arthritis with primary origin, compared to that of varus ankle arthritis and normal controls. We hypothesized that patients with valgus ankle arthritis would have the opposite pattern of lower limb alignment as those with varus ankle arthritis.

Methods

A retrospective radiographic analysis was performed on 61 patients (62 ankles, mean age, 59.3 ± 12 years) with primary valgus ankle arthritis. On preoperative radiographs, seven parameters, including talar tilt angle, medial distal tibial angle (MDTA), talar center migration, anterior distal tibial angle, talo-first metatarsal (Meary's) angle, hindfoot moment arm (HMA), and mechanical axis deviation (MAD), were measured and compared to those of primary varus ankle arthritis (n = 55; mean age, 59.7 ± 8.1 years) and control patients (n = 59; mean age, 29.3 ± 7.3 years).

Results

The valgus group had a significantly lower mean MDTA than the control group (p < 0.0001), indicating a varus distal tibial plafond in comparison to the control group. Meary's angle and HMA were significantly lower in the valgus group compared to the varus group (p < 0.05 and p < 0.0001, respectively), indicating a lower medial longitudinal arch and valgus hindfoot alignment. On whole limb radiographs, the valgus group showed a greater MAD than the control group, indicating varus lower limb alignment (p < 0.05). However, the MAD did not differ significantly between the valgus and varus groups (p = 0.7031).

Conclusion

Our findings indicate that a significant proportion of ankles with primary valgus arthritis have a varus tibial plafond and a varus lower limb mechanical axis. This study contributes to our understanding of primary valgus ankle arthritis and suggests that lower limb alignment should be analyzed and considered throughout valgus ankle arthritis realignment procedures.

中文翻译：

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原发性外翻踝关节炎患者的下肢力线：与内翻踝关节炎患者和健康对照者的比较分析

背景

虽然人们普遍认为下肢方向和脚踝和后足对齐的综合影响在踝关节炎中起着重要作用，但在外翻性踝关节炎中，踝上/下肢对齐受到的关注较少。本研究的目的是分析原发性外翻性踝关节炎患者与内翻性踝关节炎患者和正常对照者的下肢排列情况。我们假设外翻性踝关节炎患者的下肢排列方式与内翻性踝关节炎患者相反。

方法

对 61 名原发性外翻踝关节炎患者（62 个脚踝，平均年龄 59.3 ± 12 岁）进行了回顾性放射学分析。术前 X 线片显示距骨倾斜角、胫骨远端内侧角 (MDTA)、距骨中心偏移、胫骨远端前角、距第一跖骨 (Meary's) 角、后足力臂 (HMA) 和机械轴偏差 7 个参数 ( MAD) 进行了测量，并与原发性内翻性踝关节炎患者（n = 55；平均年龄，59.7 ± 8.1 岁）和对照患者（n = 59；平均年龄，29.3 ± 7.3 岁）进行了比较。

结果

外翻组的平均 MDTA 显着低于对照组 (p < 0.0001)，表明与对照组相比，胫骨远端内翻。与内翻组相比，外翻组的 Meary 角和 HMA 显着较低（分别为 p < 0.05 和 p < 0.0001），表明较低的内侧纵弓和外翻后足对齐。在全肢 X 光片上，外翻组显示出比对照组更大的 MAD，表明内翻下肢排列 (p < 0.05)。然而，MAD 在外翻组和内翻组之间没有显着差异 (p = 0.7031)。

结论

我们的研究结果表明，很大一部分患有原发性外翻关节炎的脚踝具有内翻胫骨平台和内翻下肢机械轴。这项研究有助于我们了解原发性外翻踝关节炎，并建议在整个外翻踝关节炎重新排列过程中分析和考虑下肢排列。