Ultrasound characterization of ankle involvement in Löfgren syndrome.

BACKGROUND: Bilateral ankle arthritis is a classic diagnostic criterion for Löfgren syndrome. The objective of this study was to use ultrasonography to characterize the articular and periarticular involvement of the ankles in patients with Löfgren syndrome. METHODS: Multicenter descriptive cohort study of patients with Löfgren syndrome who underwent ultrasonography of the ankles. We collected clinical data, imaging study findings, blood test results, and joint fluid properties in patients who underwent joint aspiration. RESULTS: Findings from ultrasonography of the ankles in 40 patients were analyzed. The most common B-mode abnormality was subcutaneous edema (26/40), followed by tenosynovitis (22/40), with no differences in frequency across compartments. Joint involvement manifested as synovitis in 7 patients and effusion in 10 patients. Synovitis with increased vascularity by power Doppler was found in 3 patients. No statistically significant associations were found linking synovitis or tenosynovitis to clinical features (age and gender), laboratory tests, or imaging study findings. CONCLUSION: Contrary to the classical view, our results indicate that ankle involvement in Löfgren syndrome is more often abarticular than articular. The inclusion of bilateral ankle arthritis among the diagnostic criteria for Löfgren syndrome deserves reappraisal.