Routine examination of the knee and first metatarsophalangeal joints may improve gout diagnosis, according to a study recently published in the Journal of Clinical Rheumatology. In addition, data show that older individuals who experience frequent and prolonged attacks of gout could be at increased risk for tophus.
The researchers examined 588 joints in 98 individuals with gout to evaluate the distribution of ultrasound features of lower-limb joints and the risk factors of tophus in patients with gout. The most common region for double contour was in the knee (28.6%; P =.005) and the least common was in the ankle (11.2%; P =.005). The first metatarsophalangeal joint hosted the most aggregates (P =.01), erosion (P <.001), tophus (P <.001), and synovitis (P =.001). Patients with a longer disease course presented with more prevalent tophus (P =.002), erosion (P <.001), and double contour (P =.029). Tophus and erosion were detected more among older patients (P =.028 and P =.021, respectively), with an increased risk for tophus among individuals who were older (odds ratio [OR], 3.83; 95% CI, 1.27-11.48), had a more prolonged course (OR, 6.52; 95% CI, 1.37-30.96), and had frequent attacks (OR, 3.80; 95% CI, 1.10-13.15). Effusion did not differ significantly between the 3 most commonly involved sites (P =.220).
Researchers examined participants in the United States between March and August 2017. They used the Cochran Q and chi-squared tests to study the prevalence of tophus, synovitis, effusion, double contour, aggregates, and erosion among different joints, disease courses, and ages in the sample. Finally, they used logistic regression to analyze tophus risk factors.
The study researchers conclude that “both the knee and the first [metatarsophalangeal] joints should be scanned carefully regardless of whether they are symptomatic at the time. Patients of older age with longer course and frequent attacks might have higher risks of tophus. Understanding the distribution of specific and nonspecific features in lower extremity joints and the risk factors of specific signs by [ultrasound] may promise an early diagnosis of gout.”
Zhang W, Jin Z, Xiang W, et al. Ultrasonographic features of lower-limb joints in gout: which joints and clinical characteristics would provide more information for diagnosis? [published online September 18, 2018]. J Clin Rheumatol. doi:10.1097/RHU.0000000000000898