Large Knee Swelling may be a Reason to Operate

Association of Changes in Effusion‐Synovitis and Progression of Cartilage Damage Over 18 Months in Patients with Osteoarthritis and Meniscal Tear

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First published: 22 August 2018

This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1002/art.40660



Synovitis is a feature of knee osteoarthritis (OA) and meniscal tear and has been associated with articular cartilage damage. Our study examined the associations between baseline and changes in effusion‐synovitis and changes in cartilage damage in a cohort with OA and meniscal tear.


We analyzed data from the Meniscal Tear in Osteoarthritis Research (MeTeOR) trial of surgery vs. physical therapy for treatment of meniscal tear. We performed semiquantitative grading of effusion‐synovitis and cartilage damage on magnetic resonance imaging (MRI), and dichotomized effusion‐synovitis as none/small (‘minimal’) and medium/large (‘extensive’). We assessed the association between baseline and changes in effusion‐synovitis on changes in cartilage damage size and depth over 18 months, using Poisson regression models. Analyses were adjusted for demographics, treatment, and baseline cartilage damage.


We analyzed 221 participants. Over 18 months, effusion‐synovitis was persistently minimal in 45.3% and persistently extensive in 21.3%. The remaining 33.5% had minimal synovitis on one occasion and extensive on the other. In adjusted analyses, extensive effusion‐synovitis at baseline was associated with a relative risk (RR) of 1.7 (95% CI 1.1, 2.6) for progression of cartilage damage depth. Compared to those with persistently minimal effusion‐synovitis, persistently extensive effusion‐synovitis had a statistically significant increased risk of progression of cartilage damage depth (RR 2.0 95% CI 1.1, 3.4).


The presence of extensive effusion‐synovitis is associated with subsequent progression of cartilage damage over 18 months. Persistence of extensive effusion‐synovitis over time was associated with the greatest risk of concurrent cartilage damage progression.

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