To describe the ultrasound features of nonstructural damage (effusions, synovitis, Doppler signal abnormalities) in the proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints of the fingers in patients with finger osteoarthritis compared to healthy controls.

We included patients at a hospital-based outpatient rheumatology clinic who met American College of Rheumatology criteria for finger osteoarthritis and we compared them to healthy controls. Exclusion criteria were the same in both groups. We collected demographic data and symptoms. Ultrasonography (Esaote Technos machine, two sonographers) was performed in all participants in both groups and plain radiography in the patients only. The PIP and DIP joints on fingers 2 to 5 were evaluated. Ultrasound features were compared between the two groups.

We included 55 patients (51 women; 440 PIPs and 440 DIPs) and 46 healthy controls (368 PIPs and 368 DIPs). The rate of PIP joint effusion was similar in the two groups (patients, 2.05±2.03; controls, 1.6±1.7; P>0.05), whereas the rate of DIP effusion was significantly higher in the patients (2.09±1.87 versus 0±0.6 in the controls; P<0.05). Increased vascularization by Doppler evaluation was rare and occurred chiefly in the DIP joints of the patients. None of the participants in either group had synovitis. The ultrasound abnormalities were not significantly different between right- and left-handed individuals, and neither did they correlate with clinical disease expression or severity of the radiographic damage.