Key clinical point: Ultrasound (US), magnetic resonance imaging (MRI), and X-ray could differentiate psoriatic arthritis (PsA) from psoriasis and hand osteoarthritis (OA) based on the degree of structural involvement in the distal interphalangeal (DIP)-joint and synovio-entheseal complex (SEC).
Major finding: US-detected new bone formation (NBF; risk ratio [RR] 0.52; P < .001) and DIP-joint synovial hypertrophy (RR 0.66; P = .005) along with PsA MRI scores (all P < .001) were associated with a lower risk for PsA vs. OA. Patients with PsA vs. psoriasis had a higher prevalence of X-ray entheseal change (mean difference 0.42; P = .024) and a higher trend toward US-detected NBF and erosions.
Study details: This prospective, cross-sectional study included 50 patients with DIP-joint PsA and nail involvement, 12 patients with psoriasis and nail involvement, and 13 patients with erosive and nonerosive OA.
Disclosures: The study was funded by Novartis, The Oak Foundation, and others. Some authors declared receiving speaker/consulting fees, research grants, or honoraria or serving as members of advisory board or consultants for several sources.
Source: Guldberg-Møller J et al. Multimodal imaging of the distal interphalangeal-joint synovio-entheseal complex in psoriatic arthritis (MIDAS): A cross-sectional study on the diagnostic accuracy of different imaging modalities comparing psoriatic arthritis to psoriasis and osteoarthritis. RMD Open. 2022;8:e002109 (Mar 28). Doi: 10.1136/rmdopen-2021-002109