Rheumatoid arthritis-associated cervical spine deformity and flares in disease activity.

Introduction: While rheumatoid arthritis (RA)-associated cervical spine deformity seems to be less prevalent following the introduction of the medication regimen to suppress inflammation in RA in an early stage, identifying patients at risk for atlantoaxial subluxation (AAS) or subaxial subluxation (SAS) remains challenging. Research question: The aim of the current study is to evaluate the association of the frequency of flares in systemic disease activity (DAS) and RA-associated cervical spine deformity. Materials and methods: This is a sub-analysis of the BeSt Study, where patients were treated to target DAS≤2.4. Lateral X-rays at 5- and 10-years follow-up were assessed for AAS and SAS. Results: Of 272 RA patients with radiographs of cervical spine that were included, 108 (40 %) had cervical deformity (AAS and/or SAS >2 mm). Although the number of patients with 3 or more flares was low, the majority of these patients did not demonstrate cervical spine deformity. After adjustment for the potential confounders age, gender, ACPA-status and RF-status, the presence of 3 or more flares was associated with a non-significant OR of 0.338 (95 % CI: 0.095-1.207) for the presence of RA-associated cervical spine deformity after 10 years. Discussion and conclusion: A trend towards less RA-associated cervical deformity in patients with more flares was discerned, though no statistically significant differences could be established. It is hypothesized that the occurrence of a flare leads to an increase in medication, which may in turn protect the cervical spine from developing deformities. Future studies should more in detail explore the effect of medication on cervical deformity.