Knee joint synovitis in Behcet's disease: a sonographic study

Objective. The aim of this study was to investigate, using ultrasound (US), knee involvement in patients with Behcets disease (BD). Methods. Knee US was performed in 30 unselected Italian BD patients. Signs of arthritis (joint effusion, synovial proliferation) and presence of bone erosions and Baker's cysts were recorded. Power Doppler evaluation was performed. A semi-quantitative score was used for each structure examined, whereby 0 was to indicate the absence of any change and score from 1 to 3 the presence of mild to severe changes. A sum of the single scores was obtained. Disease activity was evaluated to identify the correlation with the US modifications. Results. Twenty (66.6%) patients had symptomatic articular involvement and US showed knee involvement in 18 of them (60%). Synovial proliferation was detected in 14 (46%, positive power Doppler in 4), joint effusion in 14 (46%), bone surface erosions in 3 (10%). Four patients, asymptomatic for joint involvement, showed US alterations. Eleven patients showed a total score between 1 and 3, while the other 7 had a score between 4 and 6. Subjects with a higher US score presented an increased prevalence of acneiform skin lesions with respect to the group with US score 1-3. Statistical analysis showed a positive correlation between disease activity and US score in group 2 (p=0.04). Conclusion. This study confirms that peripheral joint involvement represents an important clinical aspect in italian BD patients and US evaluation is useful for the detection of this aspect.