Inflammatory ultrasound features show independent associations with progression of structural damage after over 2 years of follow-up in patients with hand osteoarthritis

Objective: To study the development of inflammatory features and it's relation to structural damage over a 2.3-year period in patients with hand osteoarthritis (HOA).

Methods: Synovial thickening, effusion and power Doppler signal (PDS) in distal interphalangeal (DIP), proximal interphalangeal (PIP), 1st carpometacarpal (CMC) metacarpal phalangeal (MCP) and 1st interphalangeal (IP) joints were assessed using ultrasonography in 56 consecutive HOA patients (mean age 61.2 years, 85.7% female) fulfilling American College of Rheumatology (ACR) classification criteria, at baseline and follow-up. Radiographic progression of osteophytes and joint space narrowing (JSN) was scored using the OARSI atlas. With generalised estimating equations (GEE), OR with 95% CIs were calculated for the associations between inflammatory ultrasound features and radiographic progression taking in account patient effect, age, gender, Body Mass Index, baseline osteophytes and JSN scores, and other inflammatory ultrasound features.

Results: Of 1680 joints, 8.4%, 8.7%, and 19.8% had synovial thickening, PDS or effusion at baseline, respectively. 7.1% and 5.7% of joints had progression of osteophytes and JSN, respectively. Independent associations were found between synovial thickening, effusion and PDS (grade 2-3 vs 0), and progression of osteophytes (OR (95% CI): 2.6 (1.02 to 6.5), 3.5 (1.7 to 7.4) and 5.7 (1.5 to 21.1)) and of JSN (OR (95% CI): 3.4 (1.3 to 8.4), 3.3 (1.5 to 7.6) and 3.1 (1.01 to 9.2)). Persistent inflammatory features at baseline and follow-up showed stronger associations with radiographic progression than fluctuating inflammatory features in comparison with no inflammatory features.

Conclusions: Inflammatory features, especially when persistently present, are independently associated with radiological progression in HOA after 2.3 years, indicating a role of inflammation in the aetiology of structural damage in HOA.