Analysis of the Mobility of the Distal Tibiofibular Syndesmosis in Movement of the Ankle Joint Using an Echogram

[Purpose] The purpose of this study was to make clear the mobility of the distal tibiofibular syndesmosis (dTS) when the angle of the ankle joint changes, using ultrasonic diagnostic equipment. [Subjects] We investigated 28 bilateral limbs of 14 normal adults. [Methods] The subjects moved their ankle joints from the plantar flexion position to dorsiflexion. Sequential changes of the dissociation of dTS were recorded using ultrasonic diagnostic equipment, and measured by image analysis. [Results] The dissociation increased gradually in the early stages, and rapidly in the later stages, depending on the position of the ankle joint, from plantar flexion to dorsiflexion. [Conclusion] The results suggest that the separation of dTS was related to muscular activity as well as the amplitude of the trochlea of talus.