EULAR report on the use of ultrasonography in painful knee osteoarthritis. Part 1: Prevalence of inflammation in osteoarthritis

• Published in: Annals of the rheumatic diseases 2005-12, Vol.64 (12), p.1703-1709
• Main Authors: D’Agostino, M A, Conaghan, P, Le Bars, M, Baron, G, Grassi, W, Martin-Mola, E, Wakefield, R, Brasseur, J-L, So, A, Backhaus, M, Malaise, M, Burmester, G, Schmidely, N, Ravaud, P, Dougados, M, Emery, P
• Format: Article
• Language: English
• Subjects: Aged; Arthritis; Biological and medical sciences; Cross-Sectional Studies; Diseases of the osteoarticular system; effusion; Europe - epidemiology; Extended Report; Exudates and Transudates; Exudates and Transudates - diagnostic imaging; Female; Human health sciences; Humans; Inflammation; K&L; Kellgren and Lawrence; Knee; Knee Joint - diagnostic imaging; knees; magnetic resonance imaging; Male; Medical sciences; Middle Aged; Miscellaneous. Osteoarticular involvement in other diseases; MRI; Multivariate Analysis; NMR; Nuclear magnetic resonance; Osteoarthritis; Osteoarthritis, Knee; Osteoarthritis, Knee - diagnostic imaging; Osteoarthritis, Knee - epidemiology; Pain; Pain Measurement; Prevalence; Rheumatology; Rhumatologie; Sciences de la santé humaine; Severity of Illness Index; Studies; synovitis; Synovitis - diagnostic imaging; Synovitis - epidemiology; Ultrasonic imaging; Ultrasonography; VAS; visual analogue scale; Western Ontario and McMaster Universities Osteoarthritis Index; WOMAC
• ISSN: 0003-4967; 1468-2060; 1468-2060
• DOI: 10.1136/ard.2005.037994

Objectives: To assess the prevalence of inflammation in subjects with chronic painful knee osteoarthritis (OA), as determined by the presence of synovitis or joint effusion at ultrasonography (US); and to evaluate the correlation between synovitis, effusion, and clinical parameters. Methods: A cross sectional, multicentre, European study was conducted under the umbrella of EULAR-ESCISIT. Subjects had primary chronic knee OA (ACR criteria) with pain during physical activity ⩾30 mm for at least 48 hours. Clinical parameters were collected by a rheumatologist and an US examination of the painful knee was performed by a radiologist or rheumatologist within 72 hours of the clinical examination. Ultrasonographic synovitis was defined as synovial thickness ⩾4 mm and diffuse or nodular appearance, and a joint effusion was defined as effusion depth ⩾4 mm. Results: 600 patients with painful knee OA were analysed. At US 16 (2.7%) had synovitis alone, 85 (14.2%) had both synovitis and effusion, 177 (29.5%) had joint effusion alone, and 322 (53.7%) had no inflammation according to the definitions employed. Multivariate analysis showed that inflammation seen by US correlated statistically with advanced radiographic disease (Kellgren-Lawrence grade ⩾3; odds ratio (OR) = 2.20 and 1.91 for synovitis and joint effusion, respectively), and with clinical signs and symptoms suggestive of an inflammatory “flare”, such as joint effusion on clinical examination (OR = 1.97 and 2.70 for synovitis and joint effusion, respectively) or sudden aggravation of knee pain (OR = 1.77 for joint effusion). Conclusion: US can detect synovial inflammation and effusion in painful knee OA, which correlate significantly with knee synovitis, effusion, and clinical parameters suggestive of an inflammatory “flare”.