Intra-articular steroids in radiologically confirmed tarsal and hip synovitis of juvenile idiopathic arthritis.

OBJECTIVE To estimate the value of MRI or US imaging in the diagnosis of synovitis and the response to local steroid therapy in tarsal and hip synovitis. METHODS 32 patients with juvenile idiopathic arthritis (JIA), 19 of them with 22 tarsal and 13 of them with 20 hip synovitis, were followed up for 12 months after intra-articular corticosteroid treatment (IAST). MRI was taken from swollen ankles/feet to target the inflamed area before IAST. The synovitis in hip joints was assessed by both clinical and ultrasonographic examination. RESULTS MRI showed that in the swollen tarsal area the inflammation was distributed widely in the joints and tendon sheaths. In 13/22 (59%) ankles/feet, synovitis was observed in multiple joint spaces. In 17/22 (77%) ankles/feet, tenosynovitis was present. In 32% of cases, the IAST induced clinical remission for up to 12 months. In hip synovitis, ultrasound supplemented clinical assessment. At 12 months after IAST a successful treatment response was seen in 10/20 (50%) hips. CONCLUSION In unresponsive tarsal arthritis, the synovitic sites should be targeted by radiological imaging to improve the efficacy of corticosteroid injections. For pediatric rheumatologists, easy access to US is preferable to optimize the treatment of hip and tarsal synovitis in JIA.