NEW findings from the LIHOA cohort indicate that ultrasound-detected synovitis in symptomatic hand osteoarthritis (HOA) is associated with impaired hand function, even in the absence of increased pain. The study adds to growing evidence that inflammatory changes in HOA may have important functional consequences that are not fully captured by symptom severity alone.
Investigating the Role of Inflammation in Hand OA
Hand osteoarthritis is traditionally considered a degenerative joint disease, but increasing attention has been given to the role of local inflammation. Ultrasound (US) offers a sensitive method to detect synovial changes, yet the clinical relevance of these findings in HOA remains debated.
In this cross-sectional analysis, researchers evaluated 72 patients with painful HOA who met American College of Rheumatology criteria and were assessed between 2019 and 2023. The cohort was predominantly female, with a mean age of approximately 62 years. Clinical assessments included pain scores, grip and pinch strength, functional indices, and inflammatory markers, alongside semi-quantitative ultrasound evaluation of the most painful interphalangeal joint.
Synovitis Associated With Reduced Hand Strength
The analysis showed that higher grades of grey scale synovitis were significantly associated with reduced grip strength. Patients with more pronounced synovial thickening also demonstrated lower grip strength and worse functional scores on the Functional Index for Hand Osteoarthritis, with similar trends observed on the Cochin Hand Functional Scale.
In contrast, ultrasound features were not associated with pain at rest or during movement, nor with the number of painful or nodal interphalangeal joints. Power Doppler signal was largely absent across the cohort, limiting assessment of active hypervascular inflammation.
Functional Impact Beyond Pain
The findings suggest that structural inflammatory changes within the joint may contribute to functional decline independently of pain perception. This dissociation highlights the complexity of HOA, where patients may experience reduced hand performance despite relatively stable pain levels.
Notably, ultrasound findings were not influenced by systemic inflammation, as measured by C-reactive protein, nor by the presence of osteoarthritis in joints outside the hands. This supports the idea that local joint pathology plays a central role in hand function.
Implications for Assessment and Management
The authors conclude that grey scale synovitis and synovial thickening detected by ultrasound are associated with worse physical function in symptomatic HOA, particularly reduced grip strength, but not with pain intensity. These results suggest that imaging may provide additional information beyond symptom assessment when evaluating functional impairment in hand osteoarthritis.
While the study’s cross-sectional design limits causal interpretation, the findings raise the possibility that targeting inflammatory joint changes could help preserve hand function in selected patients. Further longitudinal studies will be needed to determine whether ultrasound-detected synovitis predicts disease progression or response to therapy in hand osteoarthritis.
