Objective: To study the prevalence of cervical spine subluxations and predictive factors for atlantoaxial subluxations (including anterior atlantoaxial subluxation and atlantoaxial impaction, i.e., vertical subluxation) in patients with rheumatoid arthritis (RA) who were treated early and continuously with disease-modifying antirheumatic drugs for 8-13 years.
Methods: Radiographs of the cervical spine were obtained in 103 of 110 patients (the 110 surviving patients of the original 135-patient cohort) at their 8-13-year followup visits. The prevalence of cervical spine subluxations was determined. Demographic variables and the first 5-year serial data concerning disease course were analyzed in a logistic regression model to find predictive factors for atlantoaxial subluxations.
Results: Atlantoaxial subluxations were found in 14 patients (14%), and 5 patients (5%) had subaxial subluxations. Older age at baseline, greater disease activity during the first 5 years, and early erosiveness in peripheral joints predicted the development of atlantoaxial subluxations. Patients who had >or=10% of the maximum possible radiographic damage (by Larsen score) in peripheral joints at 5 years were 15.9 times more likely to develop atlantoaxial subluxations at 8-13 years than patients whose peripheral joint damage remained <10% of the maximum.
Conclusion: Compared with historical control RA cohorts, a lower prevalence of cervical spine destruction was found in the present group of patients. Rapid erosiveness in peripheral joints was the best predictor for atlantoaxial subluxations. Extensive erosiveness in peripheral joints should alert rheumatologists to the possible development of atlantoaxial subluxations in patients with RA.