Characteristic magnetic resonance imaging entheseal changes of knee synovitis in spondylarthropathy
Article first published online: 28 MAY 2004
Copyright © 1998 by the American College of Rheumatology
Arthritis & Rheumatism
Volume 41, Issue 4, pages 694–700, April 1998
How to Cite
McGonagle, D., Gibbon, W., O'Connor, P., Green, M., Pease, C. and Emery, P. (1998), Characteristic magnetic resonance imaging entheseal changes of knee synovitis in spondylarthropathy. Arthritis & Rheumatism, 41: 694–700. doi: 10.1002/1529-0131(199804)41:4<694::AID-ART17>3.0.CO;2-#
- Issue published online: 28 MAY 2004
- Article first published online: 28 MAY 2004
- Manuscript Accepted: 3 DEC 1997
- Manuscript Received: 22 SEP 1997
To use magnetic resonance imaging (MRI) in patients with rheumatoid arthritis (RA) and spondylarthropathy (SpA) to determine if the primary site of abnormality differs.
Twenty patients with recent-onset knee effusion (10 with SpA and 10 with RA) were evaluated using fat-suppressed MRI. Knee joint effusion and synovitis were confirmed using ultrasonography. MRI scans were independently scored by 2 observers who were blinded to the patient's diagnosis.
All 10 of the SpA patients, but only 4 of the 10 RA patients, had focal peri-entheseal high signal (compatible with fluid or edema) outside the joint (P = 0.01). Six of the SpA patients had bone marrow edema that was maximal at entheseal insertions; in 4 cases this was multifocal. No RA patients showed such an abnormality (P = 0.01).
Prominent entheseal abnormalities on MRI are a consistent feature of new-onset synovitis in SpA but are a minor feature of RA. This finding has important implications for the diagnosis, classification, and mechanisms of synovitis in patients with SpA.