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.