Peroneal tendons: use of kinematic MR imaging of the ankle to determine subluxation

The purpose of this study was to develop a technique for kinematic MRI of the ankle to evaluate subluxation of the peroneal tendons. A special device was used to perform incremental, passive positioning of the ankle from dorsiflexed to plantarflexed positions for the kinematic MRI examination. A fast spoiled gradient-recalled acquisition in the steady state pulse sequence was used to obtain axial images to assess the peroneal tendons during different positions of the ankle. Seven asymptomatic volunteers and five patients with suspected peroneal tendon subluxation were studied. There was no transverse displacement of the peroneal tendons observed in the asymptomatic subjects nor in two of the patients. Two patients had peroneal tendon subluxation observed on the kinematic MRI studies, and one patient had the peroneal tendons maintained in a displaced position in all ankle positions. The preliminary results suggest that kinematic MRI of the ankle is a potentially useful technique to facilitate evaluation of patients with suspected subluxation of the peroneal tendons, particularly in instances in which subluxation is position-dependent, and spontaneous reduction of the tendons may occur.