Persistent, extensive effusion-synovitis is associated with progression of cartilage damage over time in patients with knee osteoarthritis (OA) and meniscal tear, according to the results of a study published in Arthritis & Rheumatology.
Researchers analyzed data from the Meniscal Tear in Osteoarthritis Research (MeTeOR) trial (ClinicalTrials.gov identifier: NCT00597012), which compared surgery and physical therapy for the treatment of meniscal tear. They performed semiquantitative grading of effusion-synovitis and cartilage damage on MRI. Effusion-synovitis was categorized as either minimal or extensive. Data were collected at baseline and at the 18-month follow-up. Using Poisson regression models, the authors explored the relationship between baseline cartilage assessment and changes in effusion-synovitis on cartilage damage over the course of 18 months. The MRI OA Knee Score (MOAKS) was used to assess the extent of the cartilage damage.
The investigators analyzed data from 221 participants with baseline OA and meniscal tear. In 45.3% of these patients, effusion-synovitis was persistently minimal, whereas in 21.3% it was persistently extensive. In 33.5% of the cohort, effusion-synovitis was minimal on one occasion and extensive on the other. The adjusted analyses demonstrated a relative risk (RR) of 1.7 (95% CI, 1.1-2.6) for progression of cartilage damage depth for those with extensive effusion-synovitis at baseline. Those with extensive effusion-synovitis had a statistically significant increased risk for cartilage damage depth progression, with an RR of 2.0 (95% CI, 1.1-3.4) compared with those with persistently minimal effusion-synovitis.
The authors note that only 7% of participants developed extensive effusion-synovitis during the 18-month period. In contrast, 26% experienced a decrease in grade from extensive to minimal. The authors suggest that treatment may have affected the severity of effusion-synovitis over time.
The study was limited by the use of semiquantitative grading of effusion-synovitis, rather than quantitative grading. However, the authors note that their results appear to be consistent with previous studies using quantitative measures. They also point out that MOAKS was developed to score knee OA on MRI and that the clinical relevance for this application is unknown.
The authors note that this study demonstrates that changes in synovitis, either persistently extensive or intermittent, are associated with cartilage damage over time in patients with OA and meniscal tear. As synovitis may be modifiable, the authors suggest that future research be conducted to determine whether treatment of synovitis could alleviate cartilage damage.
MacFarlane LA, Yang H, Collins JE, et al. Association of changes in effusion-synovitis and progression of cartilage damage over 18 months in patients with osteoarthritis and meniscal tear [published online August 22, 2018]. Arthritis Rheumatol. doi: 10.1002/art.40660