Objective: To evaluate the association of abnormal signal intensity within the sinus tarsi with abnormalities of the posterior tibial tendon (PTT) on MR imaging.
Design and patients: Sinus tarsi abnormalities were identified on 30 ankle MR examinations in 29 patients. The PTT and anterior talofibular ligament were retrospectively analyzed for abnormalities in these same patients.
Results and conclusions: Tears of the anterior talofibular ligament were found in 13 of 30 (43%) ankles. PTT abnormalities (complete tear, partial tear or dislocation) were seen in 14 of 30 (47%) studies, and were distributed relatively equally between those patients with and without lateral ligament tears. Our results provide evidence of an association between abnormalities of the PTT and the sinus tarsi. The finding of abnormal signal intensity within the sinus tarsi on MR imaging should alert the radiologist to potential abnormalities of the PTT.