Analysis of the factors affecting the formation of tophi

Abstract

Objective To explore the factors what may influence the formation of tophi by high frequency ultrasound. Methods The gouty patients who were experiencing an acute attack and were clinically diagnosed with gouty arthritis were divided into two groups: the tophi group (44 cases) and the no tophi group (101 cases) group, clinical data and ultrasound features of joints were collected. The differences of ultrasound features and clinical characteristics between the two groups were analyzed. Results ① Ultrasound features showed that synovitis (χ2=8.479, P=0.004) and effusion (χ2=9.740, P=0.002) of the first metatarsophalangeal joint (MTP1) were most frequently observed in the no tophi group; bone erosion of MTP1 (χ2=9.593, P=0.003), double contour (DC) sign (χ2=14.069, P=0.000) and bone erosion (χ2=5.870, P=0.020) of ankle joint, DC sign of knee joint (χ2=8.224, P=0.006) were most frequently observed in the tophi group. Hyperechoic aggregates of MTP1 (χ2=9.649, P=0.003) were most frequently observed in no tophi group. ② Logistic regression analysis showed that MTP1 was the first attacked joint [OR=9.725, 95%CI(2.765, 34.209), P=0.000], the multiple joints involved [OR=1.908, 95%CI (1.190, 3.057), P=0.007] and bone erosion of MTP1 [OR=4.339, 95%CI(1.300, 14.490), P=0.017] were the main risks of the formation of tophi. Synovitis of MTP1 often presented in no tophi patients [OR=0.108, 95%CI(0.026, 0.441), P=0.002]. Conclusion High frequency ultrasound combine with clinical data is of great value for evaluating the development and treatment of gout. Key words: Arthritis, gouty; Musculoskeletal Ultrasound; Metatarsophalangeal joint; Hyperuri-cemia