Rheumatoid arthritis: evaluation of wrist extensor tendons with clinical examination versus MR imaging--a preliminary report.

To determine whether magnetic resonance (MR) imaging can improve assessment of the extensor tendons of the wrist and their propensity to rupture, the dorsal tendons in 23 wrists in 20 patients with rheumatoid arthritis were clinically assessed and then examined with MR imaging. Clinical and MR imaging evaluations were performed blindly and independently. The six extensor tendon compartments were assessed with MR imaging for presence of pannus, synovial effusion, and tendon involvement or rupture. Clinical scores of systemic disease, dorsal tendon sheath swelling, and risk of tendon rupture ranged from 0 to 3 in each category; the overall score was not associated with any MR imaging category. Clinical assessment of enlargement of the dorsal tendon sheath and clinical risk of rupture correlated poorly with findings on MR images. All eight wrists with clinically minimal risk of rupture had pannus, effusions, and tendon involvement on MR images; the findings were similar in the wrists with moderate (grade 2) risk of rupture. MR imaging depicts involvement of the dorsal tendon sheath and dorsal tendons that cannot be assessed with other radiologic or clinical means.