距舟关节在体运动与足内侧纵弓变化的相关性

目的通过数字化技术探讨距舟关节的在体运动特点及其对足内侧纵弓变化的影响。方法采集5名健康志愿者(4男1女)9例足部在进行内翻内收背伸运动时初始体位(中立位)和终末体位(最大内翻内收背伸位)的足部CT影像,利用mimics和geomagic逆向工程软件,结合刚体运动学原理,计算出距舟关节在足部这一运动过程中的三维空间6个自由度的变化及其与足内侧纵弓变化之间关系。结果足内翻内收背伸运动时,距舟关节发生了内翻内收跖屈运动,其内翻幅度:(38.82±5.98)°,内收幅度:(19.71±6.33)°,跖屈幅度:(-5.09±6.89)°;距舟关节运动中足舟骨向内侧移位与足内弓顶角变化具有显著相关性(P<0.05)。结论数字化技术解决了距舟关节在体三维运动测量的难题,通过这一技术的测量与分析发现:距舟关节虽然是一个杵臼状关节,但其主要进行绕矢状轴旋转,距舟关节的运动是引起足内侧纵弓变化的主要因素之一。

Correlation between talonavicular joint movement and changes of the medial longitudinal arch

Objective To explore the characteristics of the talonavicular joint movement in vivo and its effects on changes of the medial longitudinal arch.Methods Foot CT images in the initial position(neutral position) and terminal position(maximum varus-adduction-dorsiflexion position) were acquired from 9 cases(5 healthy volunteers,including 4 males and 1 female) during foot varus-adduction-dorsiflexion motion.Based on the principle of rigid body kinematics,the CT data were reconstructed and analyzed with Mimics and Geomagic reverse engineering software.The changes of the talonavicular joint in three-dimensional in 6 degrees of freedom were calculated to determine its correlation to the medial longitudinal arch angle.Results During foot varus-adduction-dorsiflexion motion,the talonavicular joint underwent varus-adduction-plantarflexion motion,with the motion range of 38.82±5.98° in varus,19.71±6.33°in adduction,and-5.09±6.89° in plantarflexion.During talonavicular joint motion,the medial shift of the navicular was significantly correlated to the changes of foot medial longitudinal arch(P<0.05).Conclusion Digital technology can solve the problem of measurement of talonavicular joint three-dimensional motion in vivo.Though as a ball-and-socket joint,the talonavicular joint mainly rotates around the sagittal axis,and its movement is a major factor to cause changes of foot medial longitudinal arch.