Knee joint synovitis in Sjögren's syndrome. Sonographic study

Ultrasound detects effusion and synovial proliferation caused by synovitis. The study was undertaken to evaluate the signs of synovitis in patients with primary Sjögren's Syndrome (SS). Joint effusion was detected and synovial thickness was measured in the suprapatellar synovial bursa. Results have been compared with those obtained by sonographic assessment of knee joint in patients with secondary SS and RA, with secondary SS and connective tissue diseases, with RA, and in healthy subjects. Synovial thickening was demonstrated in all the diseases (higher grades of thickening were found in secondary SS with RA and in RA). Joint effusion was present with significantly higher frequency in secondary SS with RA and in RA. Results demonstrated signs of slight synovitis in primary SS. More severe synovitis was found both in secondary SS with RA and in RA. This is the first sonographic study demonstrating slight synovitis in primary SS.