Background Cervical spine involvement is common and potentially severe in patients with Rheumatoid Arthritis (RA). The most common abnormality is anterior Atlanto Axial Subluxation (aAAS), which has been reported in 19–70% of patients.
Objectives The aim of this study was to determinate the prevalence of aAAS by plain radiographs and to assess its predictive factors.
Methods A cross-sectional study was carried out with RA patients diagnosed according to ACR 1987 or ACR/EULAR 2010 classification criteria. Demographic characteristics and features of disease were collected. Pain was measured using a visual analogue scale (VAS). RA activity was assessed by the Disease Activity Score (DAS 28). Functional disability was evaluated by the Health Assessment Questionnaire (HAQ). Joint destruction was assessed by the van der Heijde-modified Sharp Score. aAAS was assessed on lateral radiographs taken in flexion. The diagnosis was based on an anterior atlantodental interval (AADI) greater than 4 mm. Data analysis was carried out using the SPSS 20 Software. p<0.05 was considered statistically significant.
Results One hundred and sixteen patients with a mean±SD age of 49.07±13.23 years were recruited. Eighty-five per cent were female. Mean±SD duration of symptoms was 11.3±9.30 years. The diagnosis of aAAS was made in 11 (9.5%) of cases. RA patients with aAAS had longer disease duration, higher Sharp scores, and higher functional disability. On regression analysis, significant predictors of aAAS were disease duration (p=0.008), joint destruction (p=0.002), functional disability (p=0.028) and presence of coxitis (p=0.038). The multivariate analysis showed that structural damage was a predictive factor of aAAS (p=0.007 OR: 1.02, 95% CI 1.006–1.035) adjusted to functional disability and presence of coxitis.
Conclusions The prevalence of aAAS was 9.5% in our RA population. Larger studies are required to identify the profile of RA patients at high risk of cervical spine involvement.
Disclosure of Interest None declared