Background/Purpose: To study structural and inflammatory ultrasound lesions in elderly subjects with hand osteoarthritis (HOA) as well as in pain-free subjects with bony enlargements of finger joints.

Methods: Prospective study of 331 subjects [mean age 75.2 (±SD 7.2) years, 49.5% female], of the Bruneck Study cohort, recruited from the official population register by random sampling. Sixteen joints (wrist, CMC, MCP1-5, PIP1-5, DIP2-5) were clinically evaluated for the presence of bony enlargements, soft tissue swelling and tenderness. Ultrasound of the dorsal and palmar side of these joints was conducted using a GE Logic E ultrasound device. Osteophytes, synovial hypertrophy and/or joint effusion (SH/E), Power Doppler (PD), and erosions were subjectively graded from 0 to 3 in accordance with prior publications. The Health Assessment Questionnaire (HAQ), the Short Form Score for the Assessment and Quantification of Chronic Rheumatic Affections of the Hands (SF-SACRAH) and the Functional Index for Hand Osteoarthritis (FIHOA) were used to assess functional impairment of hands. We defined two groups according to the presence or absence of HOA: Group A were subjects fulfilling the ACR criteria (n=89, 26.9%) whereas group B were individuals with bony enlargements at finger joints, but without any hand pain, aching, tenderness or soft tissue swelling (which are entry parameters for the ACR criteria). A global ultrasound sum score was calculated for each group by summing all semiquantitative scores of the investigated US abnormalities.

Results: Eighty-nine subjects (26.9%) fulfilled the ACR criteria for HOA, 176 subjects (53.2%) were in group B. Sixty-sixpatients (19.9%) did neither fulfil the definition of group A nor that of group B and were excluded. Osteophytes were the most common finding in both groups (n=89, 100% and n=175, 99%, respectively), whereas SH/E (n=83, 93% and n=119, 68%, respectively, p<0.001) and PD (n=29, 33% and n=23, 13%, respectively, p<0.001) were more frequent in group A as compared to group B. Erosions were the least common finding (n=15, 17% and n=24, 14%, respectively, p>0.2). Grade 2 or 3 ultrasound changes were more frequently observed in group A than in group B (see Table 1). In group A, the SF-SACHRA correlated with the global SH/E (corr_coeff0.46, p<0.001) and the osteophyte score (corr_coeff0.27, p=0.036). The FIHOA score correlated with the osteophyte score (corr_coeff0.39, p=0.0028 ) as well as with the PD score (corr_coeff0.4, p<0.001). There was no association between ultrasound findings and the level of pain.

Conclusion: US-verified SH/E and PD were more common in patients with clinical HOA as compared to subjects with bony enlargement without pain. This indicates that inflammation might drive clinical symptoms in people with degenerative joint disease at hands. Whether US signs of structural changes and inflammation in asymptomatic subjects precedes clinical HOA needs to be investigated by future studies.