Anterolateral ankle impingement: MR arthrographic assessment of the anterolateral recess

PURPOSE: To determine the accuracy of magnetic resonance (MR) arthrography in assessing the anterolateral recess of the ankle. MATERIALS AND METHODS: Thirty-two patients with chronic ankle pain prospect ively underwent gadolinium-enhanced MR arthrography of the tibiotalar joint . All underwent clinical examination and were included if anterolateral imp ingement (n = 13) or a control condition (n = 19; suspected osteochondral d efect, intraarticular bodies, instability, osteoarthritis) was diagnosed. M R imaging included transverse and coronal T1-weighted and sagittal T2-weigh ted imaging sequences. Images were prospectively analyzed by two readers bl inded to the clinical diagnosis. The anterolateral gutter contour was asses sed. MR arthrographic findings were correlated with subsequent arthroscopic appearances. RESULTS: MR arthrographic assessment of the anterolateral soft tissues had an accuracy of 97%, sensitivity of 96%, specificity of 100%, negative predi ctive value of 89%, and positive predictive value of 100%. Accuracy was 100 % with clinical anterolateral impingement, with an arthroscopically confirm ed abnormality in 12 cases and a normal appearance in one. Anterolateral so ft-tissue thickening was identified at MR arthrography in 11 control cases, with arthroscopic confirmation in all. The remaining cases had normal appe arances, with an arthroscopic soft-tissue abnormality in one case and a nor mal appearance in seven. CONCLUSION: MR arthrography of the tibiotalar joint is accurate in assessin g the anterolateral recess of the ankle.