Ultrasound-detected synovitis with power Doppler signal is associated with severe radiographic damage and reduced cartilage thickness in hand osteoarthritis

Objectives: To examine ultrasound (US) features of synovitis in hand osteoarthritis (OA) joints, and to evaluate their relationship with radiological damage severity and US-detected cartilage thickness. Methods: US examination was carried out on 14 joints of both hands of 25 patients with symptomatic hand OA (HOA) and 10 age- and sex-matched control subjects. US-detected features were: synovial hypertrophy, effusion, power Doppler signal (PDS), cartilage thickness. Conventional hand radiographs were scored utilizing the Kellgren-Lawrence and Kallman systems. HOA patients were divided into two subsets: non-erosive and erosive. Results: Among the three groups of subjects studied, erosive OA showed the highest values of radiological scores and the highest prevalence of US-detected synovitis. Joints positive for US synovitis features (above all PDS) had higher radiological scores and lower cartilage thickness, while joints with X-ray detected central erosions [the hallmark of erosive HOA were more likely to present PDS positivity. US measured cartilage thickness inversely correlated with radiological damage scores. Conclusions: US-detected synovitis is present in about 10% of HOA finger joints and is associated with more severe radiological damage and reduced cartilage thickness. PDS and cartilage thickness (mm) may represent two innovative additional information tools provided by ultrasonography in HOA evaluation.