The Influence of Reducing Disease Activity Score on Cervical Spine Deformity in Rheumatoid Arthritis: A Systematic Review.

Background: Rheumatoid arthritis (RA) can cause deformity in particularly the craniocervical but also in the lower cervical region. Objectives: The aim of this study is to give an overview of current literature on the association of disease activity score (DAS) and the prevalence and progression of rheumatoid arthritis-associated cervical spine deformities. Methods: A literature search was done in PubMed, Embase, and Web of Science using a sensitive search string combination (Supplemental File). Studies describing the association between DAS and the incidence and progression of atlantoaxial subluxation, vertical subluxation, and subaxial subluxation were selected by predefined selection criteria, and risk of bias was assessed using a Cochrane checklist adjusted for this purpose. Results: Twelve articles were retrieved, and risk of bias on study level was low to moderate. In the eight longitudinal studies, patients demonstrated high DAS at baseline, which decreased upon treatment with medication: cervical deformity at the end of follow-up was associated with higher DAS values. The four cross-sectional studies did not demonstrate a straightforward correlation between DAS and cervical deformity. Deformity progression was evaluated in three studies, but no convincing association with DAS was established. Conclusion: A positive association between prevalence of cervical spine deformities and high disease activity was demonstrated, but quality of evidence was low. Progression of cervical deformity in association with DAS control over time is only scarcely studied, and future investigations should focus on halting of deformity progression.