Unilateral Versus Bilateral Ultrasound of the Hands in Patients With Clinically Suspect Arthralgia: What Is the Difference? A Longitudinal Study

Objective In clinically suspect arthralgia (CSA), ultrasound (US) can be used to detect subclinical joint inflammation, which is a known predictor for progression to clinically apparent inflammatory arthritis (IA). Although most US protocols include both hands, a more efficient, unilateral US approach is also sufficient but has never been investigated. Therefore, we described US findings for 1 hand and both hands in patients with CSA and investigated if a US protocol that includes 1 hand is as predictive as a protocol with 2 hands.

Methods Two cohorts of patients with CSA underwent bilateral US. Subclinical synovitis and tenosynovitis (grayscale ≥ 2 and/or power Doppler ≥ 1) in 1 hand and both hands were described per hand and joint. Additionally, we analyzed the association between IA development and US positivity.

Results In total, 320 patients with CSA were studied. In cohort 1, 23% of patients had bilateral US-detected subclinical (teno)synovitis, 20% in the dominant hand only, and 10% in the nondominant hand only. In cohort 2, 10% had bilateral involvement, 12% in the dominant hand only, and 8% in the nondominant hand only. US of the dominant hand predicted IA development almost equally as US of both hands, with hazard ratios (HRs) of 2.8 (95% CI 1.3-6.0) for both hands and 2.6 (95% CI 1.3-5.3) for the dominant hand in cohort 1. In cohort 2, HRs were comparable.

Conclusion US-detected subclinical (teno)synovitis in patients with CSA is partly bilateral and partly unilateral. Predictive values for IA development are comparable. To reduce scanning time in clinical practice, clinicians could consider scanning 1 hand instead of both hands in patients with CSA.