Ultrasound-Detected Knee Synovitis in Patients with Rheumatoid Arthritis after Total Knee Arthroplasty.

Objectives: To evaluate the prevalence of ultrasound (US)-detected knee synovitis in patients with rheumatoid arthritis (RA) with a history of total knee arthroplasty (TKA) and to explore its association with RA disease activity and clinical outcomes.

Methods: The present, retrospective, cross-sectional study retrieved the data from electronic medical records of patients with RA who were followed up for TKA and had musculoskeletal ultrasound assessment at the study center from January 1, 2021, through December 31, 2021.

Results: Forty-two patients with 67 post-TKA knee joints were enrolled in the present study. US-detected synovitis of the post-TKA knee was present in 15 knees (22.4%) and 12 patients (28.6%). There was no difference in disease activity scores or the pain domain of Knee Injury and Osteoarthritis Outcome Score between the patients with (n=12) and without (n=30) US-detected knee synovitis. The proportion of patients with the intensification of anti-rheumatic drugs after musculoskeletal ultrasound assessment was significantly higher in patients with US-detected synovitis compared to those without US-detected synovitis (41.7% vs. 6.7%, p = 0.01).

Conclusions: US-detected synovitis of the knee was present at 22.4% of post-TKA knee joints. Patients with US-detected synovitis of post-TKA knees were likely to receive an intensification of anti-rheumatic drugs.