Hidden gout- Ultrasound findings in patients with musculo-skeletal problems and hyperuricemia

The goal of this study was to investigate the frequency of gout-specific ultrasonography findings in a cohort of hyperuricemic patients with various musculo-skeletal complaints. A blinded examiner regarding the patients' clinical and laboratory assessment performed standardized ultrasound examinations of 12 joints in 74 individuals with diverse musculo-skeletal complaints. Gout-specific changes were assessed and combined with the patients' medical history (diagnosis gout vs. non-gout) and laboratory values of hyperuricemia. Of 74 patients, 58 (mean age 55 yrs) had hyperuricemia (serum uric acid levels > 7 mg/dl/420 mu mol/L). Of those, 27 (47%) had a history of gout attacks. In total, 888 joints were examined by ultrasound. With 44/324 joints (14%) the pathological finding most often found in joints of gout patients was the double contour sign compared to 29/372 joints (8%) in patients with asymptomatic hyperuricemia and 2/192 joints (1%) in normouricemic controls. In patients with gout, the ultrasound showed pathological findings in 67/324 joints (21%). In 26/39 (67%) previously affected joints, gout-specific sonographic indications were found. With regard to the first metatarsophalangeal joint, sonographic pathologies were detectable in 16/22 (73%) so far asymptomatic joints on the contralateral. Ultrasonographic gout-specific signs are not only found in joints affected by gout attacks, but often also in the corresponding contralateral, asymptomatic joint. Patients with asymptomatic hyperuricemia already showed sonographic features implicating an as yet "silent" precipitation of urate crystals. As the examined cohort represents patients at high risk, further research for gout-specific findings is indicated, especially for hyperuricemic patients.