Department of Biology, Duke University, Durham, NC.
Department of Mathematics, College of Natural Sciences, Ajou University, Gyeonggi, Korea.
Medicine (Baltimore). 2021 Nov 12;100(45):e27637. doi: 10.1097/MD.0000000000027637.
There has been no study evaluating the change of limb alignment for patients with genu valgum. The purpose of this study was to investigate the change of limb alignments in children and adolescents with idiopathic genu valgum through evaluating distal femur, proximal tibia, and knee joint line.Consecutive children and adolescents, under the age of 18, with genu valgum were included. Mechanical tibiofemoral angle, mechanical lateral distal femoral angle, mechanical medial proximal tibia angle, and joint line convergence angle were measured. The rate of changes for each radiographic measurement were analyzed using a linear mixed model.A total of 1539 teleroentgenograms from 518 limbs of 273 individuals were included in this study. Linear mixed model showed that the change of limb alignment was significantly associated with age, but not associated with gender and laterality. The mechanical tibiofemoral angle was most valgus initially, decreasing until reaching its lowest value of 2.8° at 10 years old. The mechanical lateral distal femoral angle decreases from initial neutral alignment and increases in valgus continuously. The mechanical medial proximal tibia angle decreases from initial valgus and progresses to be neutral at around the age of 10. The joint line convergence angle decreases sharply from initial valgus alignment to 0° at the age of 5.Valgus alignment in children with idiopathic genu valgum decreases until approximately the age of 10. In younger children, the tibia and joint line contribute most to overall valgus alignment; in older children, the femur contributes the most. Based on our results, we recommend monitoring patient limb alignment until it stabilizes around the age of 10, and then carefully planning and performing corrective surgery with complete consideration of the changing bony alignment.
尚未有研究评估膝内翻患者下肢对线的变化。本研究旨在通过评估远端股骨、近端胫骨和膝关节线来研究特发性膝内翻儿童和青少年下肢对线的变化。
连续纳入特发性膝内翻的儿童和青少年，年龄在 18 岁以下。测量机械胫股角、机械外侧远端股骨角、机械内侧近端胫骨角和关节线会聚角。使用线性混合模型分析每个影像学测量值的变化率。
本研究共纳入 273 名患者 518 侧肢体的 1539 张下肢全长正位片。线性混合模型显示，下肢对线的变化与年龄显著相关，与性别和侧别无关。机械胫股角最初最外翻，直到 10 岁时降至 2.8°的最低值。机械外侧远端股骨角从初始中立对线开始减小，逐渐变为外翻。机械内侧近端胫骨角从初始外翻开始减小，大约 10 岁时变为中立。关节线会聚角从初始外翻对线急剧减小至 5 岁时的 0°。
特发性膝内翻儿童的外翻对线在大约 10 岁时减小。在年幼的儿童中，胫骨和关节线对线对整体外翻对线的影响最大；在较大的儿童中，股骨对线的影响最大。根据我们的结果，我们建议在 10 岁左右监测患者下肢对线，直到其稳定，然后仔细规划和进行矫正手术，并充分考虑不断变化的骨骼对线。
