How to score the wrist joint by ultrasound: exploration of the most sensitive joint assessment during follow-up of early or established rheumatoid arthritis

BACKGROUND: Wrist inflammation is common in patients with rheumatoid arthritis (RA), and thus there is room for debate on which joints to include in an ultrasound-based scoring of wrist synovitis in RA. This study aimed to identify the most treatment-sensitive major wrist joint, and assess potential differences between patients with early and established RA.

METHODS: This post-hoc study analysed data from two independent cohorts, the ARCTIC trial (early RA) and the ULTRABIT study (established RA), with ultrasound-based semi-quantitative scoring of 36 joints and four tendons, including the radio-carpal (RC), inter-carpal (IC), and radio-ulnar (RU) joints of the wrists. Each joint was explored separately, along with the maximum score from two (RC, IC) or three (RC, IC, RU) joints, and the sum score of two (RC and IC, IC and RU, or RU and RC) or all three (RC, IC, and RU) joints. Sensitivity to change over 12 months for each wrist joint score was assessed using the standardised response mean (SRM).

RESULTS: We included 208 and 162 patients with early and established RA, respectively. Patients with established RA showed a higher prevalence of wrist joint synovitis at baseline and 12 months than those with early RA. The maximum score of the three wrist joints was most sensitive to change in early RA; SRMs of the greyscale (GS) and power Doppler (PD) were -0.82 and -0.73, respectively. The SRM of the sum score of the three wrist joints was highest in established RA, with SRMs for GS of -0.56 and PD of -0.54, which were comparable to SRMs of maximum score of the three wrist joints.

CONCLUSIONS: To assess changes in follow-up studies, ultrasound scoring should include all three major wrist joints in both early and established RA.

TRIAL REGISTRATION: The ARCTIC trial: ClinicalTrials.gov identifier: NCT01581294. Registered on 21 September 2010. ULTRABIT trial: Australian New Zealand Clinical Trials Registry; identifier: ACTRN12610000284066. Registered on 8 April 2010.

SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13075-025-03668-8.