Unilateral destructive wrist synovitis in juvenile idiopathic arthritis.

OBJECTIVE To describe the clinical and radiographic features of a group of juvenile idiopathic arthritis (JIA) patients who developed unilateral destructive wrist synovitis. METHODS All wrist radiographs performed yearly between 1986 and 2002 in JIA patients who had wrist involvement were retrospectively reviewed to identify patients who had unilateral erosive wrist synovitis, defined as a difference of at least -3 units in the Poznanski score between the affected wrist and the unaffected wrist, with the Poznanski score in the unaffected wrist being > -2 units throughout the follow-up period. Clinical and radiographic data obtained during follow-up were recorded for all patients. RESULTS Of a total of 250 patients for whom we had approximately 900 wrist radiographs, 6 patients were found to have unilateral erosive wrist synovitis. The JIA onset subtype was oligoarticular in 5 patients and polyarticular in 1 patient and the disease duration from presentation to the last follow-up visit ranged from 2 to 16 years. The arthritis course was polyarticular in all patients. Five patients had positive antinuclear antibodies (ANA) and 1 had positive rheumatoid factor (RF). At the last follow-up visit, all patients had some impairment of wrist function and 2 patients had wrist subluxation. There was a marked radiographic damage in all affected wrist, with the Poznanski ranging from -8.0 to -8.50 units in 3 patients and being -5.5, -3.1 and -2.4 units, respectively, in 3 patients. The severity of radiographic damage in the ANA-positive patients with the longest disease duration was comparable to that observed in the RF-positive patient. CONCLUSION Unilateral erosive wrist synovitis seems to be uncommon in JIA. Patients with unilateral wrist synovitis may be at risk of a destructive course irrespective of the JIA onset subtype.