Current prevalence and characteristics of cervical spine instability in patients with rheumatoid arthritis in the era of biologics.

OBJECTIVES

Cervical spine instability (CSI) is commonly involved in patients with rheumatoid arthritis (RA). Although the treatment for RA has dramatically changed due to methotrexate and biologics, it is unclear whether this change contributes to the prevalence of CSI or not. Our objectives were to update the current prevalence of CSI and to investigate the factors associated with CSI.

METHODS

A cross-sectional study of patients with RA was conducted in our outpatient clinic. Clinical information and symptoms related to CSI were obtained. Plain radiography and magnetic resonance imaging were performed. CSI included atlantoaxial subluxation (AAS), vertical subluxation (VS), and subaxial subluxation (SAS).

RESULTS

Two hundred and twenty patients were analyzed, 93 (42%) of whom had CSI. A ≥ 10-year disease duration, Steinbrocker stage III, and three or more narrowed disc spaces from C2/3 to C6/7 were significantly associated with CSI. A neck pain VAS was associated with VS, but not with AAS and SAS. In contrast, methotrexate and biologics had no effect on CSI.

CONCLUSION

The prevalence of CSI in this study was lower compared to previous reports before the approval of biologic, although we failed to detect the effect of biologics. Further prospective studies are needed to elucidate the efficacy.