Tarsal sinus: Arthrographic, MR imaging, MR arthrographic, and pathologic findings in cadavers and retrospective study data in patients with sinus tarsi syndrome

PURPOSE: To evaluate the tarsal sinus by using different imaging techniques and specialized planes. MATERIALS AND METHODS: Magnetic resonance (MR) imaging of the tarsal sinus was performed in 10 cadavers. Conventional arthrography of the anterior and posterior subtalar joints was then performed. Tarsal sinus ligaments were evaluated further on initial and reconstructed MR arthrograms along and per pendicular to their axes. Pathologic correlation was performed in five spec imens suspected of having tarsal sinus lesions on the basis of initial imag ing findings. In 37 patients with a clinical diagnosis of sinus tarsi syndr ome, MR images of the ankle were obtained before and after intravenous gado linium-based contrast, material administration and were reviewed to verify the integrity of the tarsal sinus ligaments. RESULTS: Two complete and three partial cervical ligament (CL) tears and on e complete interosseous talocalcaneal ligament (ITCL) tear were diagnosed w ith MR imaging. Only one complete and one partial CL tear were seen after e valuation of both initial and reconstructed MR arthrograms and confirmed wi th pathologic correlation. In 18 patients, the diagnosis was confirmed at M R imaging, which depicted ITCL and CL tears in 11 patients, isolated CL tea rs in three patients, ganglia in three patients, and pigmented villonodular synovitis in one patient. CONCLUSION: Cadaveric study results indicate tha t initial and reconstructed MR arthrograms along and perpendicular to the l igament axes are potentially useful for further evaluation of individual ta rsal sinus structures.