Identification and prevalence of rheumatoid nodules in the finger tendons using high frequency ultrasonography

Rheumatoid nodules are classical diagnostic feature of rheumatoid arthritis (RA). The prevalence of rheumatoid nodules in the finger tendons is not known. We determined the prevalence of rheumatoid nodules of finger tendons in patients with RA, using high frequency linear transducers with high resolution ultrasonography.

The study comprised 54 consecutive patients with RA and 20 controls. Dynamic ultrasound examination of various tendons was performed using real-time equipment, the Apogee 800 ATL, with an 11 MHz linear array transducer.

RA nodules were identified in 9 patients (16.66%); their sizes ranged from 0.21 to 0.95 cm (mean 0.35+/-0.12 cm), in 4 cases (7.4%) the nodules were intratendinous. The flexor tendons were affected in the 9 patients. The finger tendon ultrasonography identified RA nodules that had escaped routine clinical detection.

The ultrasonography technique was valuable in the confirmation of rheumatoid nodule involvement of the finger tendons. The prevalence of rheumatoid nodule in finger tendons was 16.66%. We believe that ultrasonography should be the screening procedure of choice for diagnosis of RA nodules of the fingers.