Objective:

To analyze the association between joint tenderness and ultrasound abnormalities in anti-cyclic citrullinated peptide-positive patients with musculoskeletal symptoms but no clinical arthritis.

Approach:

• Study Design: Cross-sectional analysis of baseline data from 323 participants in the CCP Study, focusing on those with physical examination, pain questionnaire, and ultrasound scan completed on the same day.
• Participants: Eligible participants were aged 18 years or older, tested positive for anti-cyclic citrullinated peptide antibodies, and had new nonspecific musculoskeletal complaints without clinical arthritis or a history of inflammatory arthritis.
• Assessment Methods: Joint tenderness assessed by a rheumatologist; ultrasound evaluated gray-scale synovitis, power Doppler activity, tenosynovitis, and erosions.
• Statistical Analysis: Joint-level associations were evaluated using generalized estimating equation logistic models, adjusting for age and sex.

Key Findings:

• Joint tenderness was more consistently associated with ultrasound abnormalities than patient-reported joint pain.
• Significant associations were found between tenderness and gray-scale abnormalities, power Doppler activity, tenosynovitis, and erosions.
• Absence of tenderness had high negative predictive values for power Doppler activity, tenosynovitis, and erosions.
• Positive predictive values for tenderness indicating ultrasound abnormalities were generally limited.

Interpretation:

The findings suggest that joint tenderness may be a more reliable indicator of ultrasound abnormalities than patient-reported pain, but the study does not establish a clinical scanning strategy.

Limitations:

• Adjustment was made only for age and sex.
• Regional pain reporting rather than joint-specific.
• Dichotomization of ultrasound scores.
• Protocol and equipment changes during recruitment.
• Low event counts at some joints.
• Absence of formal reliability testing.

Conclusion:

The study highlights the need for further research to evaluate the role of physical examination findings in guiding ultrasound assessments in patients at risk for rheumatoid arthritis.

Sources:

• BMJ Open