MRI of the wrist in early rheumatoid arthritis can be used to predict functional outcome at 6 years.

Objectives: To determine whether magnetic resonance (MR) scans of the dominant wrist of patients with early rheumatoid arthritis (RA) can be used to predict functional outcome at 6 years' follow up.

Methods: Dominant wrist MR scans were obtained in 42 patients with criteria for RA at first presentation. Patients were followed up prospectively for 6 years, and further scans obtained at 1 year (42 patients) and 6 years (31 patients). Two radiologists scored scans for synovitis, tendonitis, bone oedema, and erosions. The Stanford Health Assessment Questionnaire (HAQ) score, indicating functional outcome, and standard measures of disease activity were assessed at 0, 1, 2, and 6 years. The physical function component of the SF-36 score (PF-SF36) was also used as a functional outcome measure at 6 years.

Results: Baseline MR parameters, including bone oedema score and the total baseline MR score, were predictive of the PF-SF36 at 6 years (R2 = 0.22, p = 0.005 and R2 = 0.16, p = 0.02, respectively). The PF-SF36 score correlated strongly with the HAQ score at 6 years (rs = -0.725, p<0.0001); none of the baseline MR parameters predicted the 6 year HAQ score. The total MR score obtained at 1 year was predictive of the 6 year HAQ (R2 = 0.04, p = 0.01). Standard clinical and radiographic measures at baseline were not predictive of the 6 year PF-SF36, but when combined in a model with baseline MR oedema score, prediction increased from 0.09 to 0.23, or 23% of the 6 year variance.

Conclusion: MR imaging of the wrist in patients with early RA can help to predict function at 6 years and could be used to plan aggressive management at an earlier stage.