Ankle Disease in Juvenile Idiopathic Arthritis: Ultrasound Findings in Clinically Swollen Ankles

Objective. The ankle joint is frequently involved in juvenile idiopathic arthritis (JIA), but it is unclear whether this is predominantly due to synovitis, tenosynovitis, or both. We performed clinic-based ultrasound examination to assess the prevalence of synovitis and tenosynovitis in children with JIA felt clinically to have active inflammatory disease of the ankle. Methods. Thirty-four patients with 49 clinically swollen ankles were Studied (19 polyarticular JIA, 13 oligoarticular JIA, I systemic JIA, I psoriatic JIA). All cases had at least one clinically swollen ankle joint. The children were assessed clinically and had ultrasound examination during routine clinic appointments. Results. We found 71% of ankles had tenosynovitis and 39% had tenosynovitis alone. Only 29% of swollen ankles had a tibiotalar effusion alone. We found 33% had both tenosynovitis and a tibiotalar effusion. When results were analyzed by JIA subtype, we found 81% of oligoarticular JIA ankles had medial ankle tenosynovitis but Only 19% had tibiotalar effusion alone. There was a significant difference between JIA Subgroups for the frequency of occurrence of medial ankle tenosynovitis (p 0.048) and lateral ankle tenosynovitis (p = 0.001). Conclusion. The tibiotalar joint was not involved in 39% of the swollen ankles; and tenosynovitis, sometimes in isolation, was the dominant finding. This has implications for therapeutic intervention and also for an improved classification of children with JIA, especially with ankle involvement. (First Release May I 2009; J Rheumatol 2009;36:1725-9. doi: 10.3899/jrheum.080508)