Risk factors for the formation of double-contour sign and tophi in gout

BACKGROUND: This study aimed to confirm the diagnostic accuracy of ultrasound (US) on gout and explore the potential risk factors for double-contour sign and tophi formation in gout patients. METHODS: The US analyses were performed on all knee, ankle, and first metatarsophalangeal (MTP 1) joints to reveal the type and location of lesions. While a questionnaire and blood biochemical index were used to explore the potential risk factors for double-contour sign and tophi in gout, the SPSS17.0 software was used for statistical analysis in the present study. RESULTS: Totally, 117 gout patients with 702 joints (38 lesions in knee joint, 93 lesions in ankle joint, and 112 lesions in MTP 1 joint) were enrolled in current analyses. Double-contour sign and joint effusion were the two most outstanding lesion manifestations in knee joints and ankle joints. Tophi and double-contour sign were the two most outstanding lesion manifestations in TMP 1 joints. Moreover, factors including uric acid (UA) level and the highest blood UA were potential risk factors of the double-contour sign, while age and history of US were potential risk factors for tophi. CONCLUSION: US was effective on the joints of gout patients. There was US sensitivity for tophi and double-contour sign in MTP 1 joints. The double-contour sign was a potential specific manifestation in knee joints and ankle joints. Furthermore, UA and highest blood UA level were potential risk factors for double-contour sign, while age and US history were potential risk factors for tophi.