Ⅱ期成人获得性平足与正常成人足距下关节运动三维测量对比研究

Comparative analysis of subtalar joint motion in vivo of the stageⅡ flat foot and normal foot at different terminal positions

目的对Ⅱ期成人获得性平足和正常成人足志愿者距下关节运动进行不同终末位置活体测量评估对比,为深入了解平足畸形发病机制及选择治疗手段提供基础依据。方法 2010年3月至2013年9月,分别招募Ⅱ期成人获得性平足和正常成人足志愿者各30名,经过入组前排除标准的筛选,最后选取每组符合入选标准的志愿者各20名。指导入组志愿者将单足固定于自行设计的足踝部运动装置的不同终末位置(中立位、最大背伸位、最大跖屈位、最大内翻位、最大外翻位、最大内旋位及最大外旋位)进行CT扫描,将获得的DICOM格式数据导入三维重建软件Mimics 14.11中进行三维重建,将三维重建骨块模型分别导入Geomagic13.0软件,使用二次配准方法对三维模型各终末位置进行三维测量,并通过Geomagic软件自动测算出距下关节三维旋转和位移,对数据进行统计对比分析。结果Ⅱ期成人获得性平足与正常成人足距下关节在冠状轴、矢状轴和垂直轴上旋转和平移对比显示,中立位至最大背伸位时距下关节活动无明显差异(P>0.05);中立位至最大跖屈位时距下关节活动在冠状轴上表现出更加背伸并向外侧移动,在垂直轴上表现出更加外展(P<0.05);中立位至最大内翻位时距下关节活动在矢状轴上表现出更加外翻,在冠状轴上表现出向外侧移动,在垂直轴上表现出更加外展并向肢体远侧移动(P<0.05);中立位至最大外翻位时距下关节活动在矢状轴上表现出更加内翻并向前侧移动,在冠状轴上表现出向内侧移动,在垂直轴上表现出更加内收(P<0.05);中立位至最大内旋位时距下关节活动在垂直轴上表现出更加外展(P<0.05);中立位至最大外旋位时距下关节活动在垂直轴上表现出更加内收(P<0.05)。结论在足踝部不同终末位置,Ⅱ期成人获得性平足距下关节活动度较正常成人足增大,尤其以最大内翻位及最大外翻位为甚。

Objective To evaluate the motion in vivo of the subtalar joint and make the comparison in volunteers with normal foot and stage Ⅱ fiat foot, thus to provide the basis for advanced understanding pathogenesis and choices of treatment on stage Ⅱ flat foot. Methods From March 2010 to September 2013, thirty volunteers with normal foot and stage Ⅱ flat foot were recruited respectively. Before being assigned to the group, some of them were excluded by the exclusion standard. Finally, twenty in each group were selected. CT scans were performed on their feet which were fixed in different terminal postions （including neutral position, maximal dorsiflexion/plantarflexion, maximal varus/valgus position, maximal internal rotation/external rotation） on the device for the motion of foot and ankle designed by our department. The digital imaging and communications in medicine （DICK）M） data obtained from the CT could be imported to Mimics 14. 11 software to reconstruct a three-dimensional model, then exported it to the Geomagic 13.0 software for three-dimensinal analysis of different positions using a twice registration method. Collected data were compared and analyzed. Results The motion analysis of the flat foot in contrast to normal ones were listed below： No significant difference were presented between the two groups from the neutral position to the maximal dorsiflexion （P〉0. 05）. The talus presented more dorsiflexion and translated more to the lateral side at the coronal axis while more abducted at the vertical axis from the neutral position to the maximal plantarflexion, the difference between the two groups was significant （P〈0.05）. The talus presented more valgus at the sagittal axis, translated more to the lateral side at the coronal axis, more abducted and translated more to the bodily distal side at the vertical axis from the neutral position to the maximal varus position, the difference between the two groups was significant （P〈0. 05）. The talus presented more valgus and translated more to the anterior side at the sagittal axis, translated more to the medial side at the coronal axis, and more adducted at the vertical axis from the neutral position to the maximal valgus position, the difference between the two groups was significant （P〈C0. 05）. The talus presented more abducted at the vertical axis from the neutral position to the maximal internal rotation, the talus presented more adducted at the vertical axis from the neutral position to the maximal external rotation, the difference between the two groups was significant （P〈0.05）. Conclusions Stage n flat foot presented more range of motion in the subtalar joint, especially in terms of varus and valgus positions compared with normal foot.