Chronic ankle instability: evaluation with MR arthrography, MR imaging, and stress radiography.

PURPOSE: To compare the efficacy of conventional magnetic resonance (MR) imaging, MR arthrography, and stress radiography in the detection of lateral collateral ligament abnormalities in patients with chronic ankle instability. MATERIALS AND METHODS: Seventeen patients with chronic lateral ankle instability underwent stress radiography, MR imaging, and MR arthrography after intraarticular injection of gadopentetate dimeglumine. Imaging findings were correlated with surgical findings. RESULTS: The anterior talofibular (ATF) ligament was torn in 14 patients, and the calcaneofibular (CF) ligament was torn in 10. MR arthrography was more accurate and sensitive in the detection of ATF tears than was MR imaging or stress radiography (P < or = .05). Associated injuries were detected with both MR imaging and MR arthrography. CONCLUSION: MR arthrography is a sensitive technique for detecting and staging tears of the lateral collateral ligaments.