Limited Diagnostic and Prognostic Value of Routine Radiographs in Newly Presenting Arthritis Suspected of Rheumatoid Arthritis: A Retrospective Study.

Objective: Current recommendations suggest that patients with newly presenting arthritis suspected of rheumatoid arthritis (RA) should undergo routine radiographs of hands and feet (X-HF) as the presence of RA-associated erosions might be of diagnostic and prognostic value. Our objective was to investigate the prevalence, diagnostic, and prognostic value of RA-associated erosions seen on routine X-HF in a large, recent cohort of patients with newly presenting arthritis.

Methods: A retrospective cohort study was performed between 2016 and 2019 in patients with newly presenting arthritis suspected of RA. Patients were included if arthritis was present at diagnosis, rheumatoid factor and anticitrullinated protein antibodies were measured, RA was noted in the differential diagnosis, and routine X-HF were conducted. Outcomes were the prevalence of one or more RA-associated erosion(s), and whether diagnostic or prognostic classification were changed by erosivity. Seronegative patients, patients without acute phase reactants, and patients with longer symptom duration were analyzed as subgroups.

Results: RA-associated erosions were found in 32 of 724 patients (4.4%, 95% confidence interval [95% CI] 3.1-6.2). Erosions led to a change of diagnostic classification in two patients (0.3%, 95% CI 0.01-1.1) and changed prognostic classification in three patients (0.4%, 95% CI 0.1-1.3). Seronegative patients and patients without elevated acute phase reactants had significantly lower prevalence of erosions (χ 9.4, P = 0.002, χ 6.5, P = 0.01). Longer symptom duration was not associated with a different prevalence of erosions (χ 0.4, P = 0.81).

Conclusion: The recommendation of conducting routine X-HF in patients with newly presenting arthritis suspected of RA might be reconsidered due to low prevalence of early erosive disease and lack of diagnostic and prognostic value.