Objective:To determine the prevalence and associated factors ofatlanto-axial subluxation in patients with rheumatoid arthritis (RA).

Material and Method:A cross-sectional study using database of patients with RA who visited rheumatologic clinic inthe authors’ institution between September 2014 and February 2015 was performed. Data collected were demographic, laboratory and imaging data.

Results: During the study period, 231 patients were included. The mean age was 55.2 ± 11.8 years. Majority of patients (92.6%) were female. Atlanto-axial subluxation was found in 40 patients (17.3%): 35 (15.1%) had anterior type only, two (0.9%) had vertical type, and three (1.3%) had combined anterior and vertical subluxation. Factors which were significantly associated with atlanto-axial subluxation were simple disease activity index score (p = 0.024), health assessment questionnaire score (p < 0.001) and modified total sharp score (p = 0.002). There were no association between atlanto-axial subluxation and age, sex, anti–cyclic citrullinated peptide antibody, rheumatoid factor, duration of disease, extra-arthricular manifestation, drug use, disease activity score 28, clinical disease activity index, C-reactive protein, IL-6 and procalcitonin.

Conclusion: Atlanto-axial subluxation is highly prevalent in RA patients. Factors associated with atlanto-axial subluxation represent high disease activity, high degree of functional disability and radiological severity of RA.