During the poster session at the 2015 CRA meeting on Friday, Dr. Tony Zhang presented a systematic review of the literature to determine if cervical spine (C-spine) complications in rheumatoid arthritis (RA) are changing over time. It has been the impression of rheumatologists that RA has become less severe over the last few decades, e.g., there is less vasculitis, corneal melts, rheumatoid nodules and less damage overall.
With that in mind, Dr. Zhang performed a meta-analysis of published literature to determine if the rate of C-spine involvement is decreasing over time. Only studies of at least 100 RA patients were included. Over 12,000 citations resulted in 59 articles being selected for inclusion. The prevalence of anterior atlanto-axial subluxations (aAAS) decreased from 36% (95%CI: 30%-42%) before the 1980s to 24% (95%CI: 13%-36%) in the 2000s (p=0.04). These were the most common RA subluxations found throughout the years.
The overall prevalence of vertical subluxations (VS) was 11% (95%CI: 10%-19%), 13% (95%CI: 12%-20%) for subaxial subluxations (SA) and cervical myelopathy 5% (95%CI: 3%-9%) without significant temporal changes. The rate of progression of aAAS, VS, and SA subluxations was 4, 6, and 3 lesions per 100 patients per year, respectively.
The incidence of new or progressive cervical myelopathy occurred at a rate of 2 cases per 100 patients with known cervical subluxations per year. Since the 1960s, only rates of aAAS have decreased dramatically. It is still more than twice as common as VS or SA. No temporal changes in the development of cervical myelopathy in affected RA patients were noted. The progression rate of cervical subluxations and myelopathy was unchanged over time.
The second question was to determine what the rate of progression of cervical lesions was in RA. Cervical myelopathy was assessed in 1,310 RA patients with 9,131 person-years follow-up. A total of 772 people had AAS, VS, SA or a combination of subluxations. Seventy-nine had new or progressive cervical myelopathy at the end of follow-up. The rate was found to be 1.5 new or progressive cervical myelopathy per 100 patients with known cervical subluxations per year.
There was heterogeneity in the meta-analysis. There could have been publication of cohorts with high rates of C-spine involvement in any of the time periods. Dr. Zhang was unable to ascertain the contribution of effective treatment and the lower rate of subluxations over time.
This may indeed demonstrate that the most common form of neck involvement in RA is decreasing over time and supports the hypothesis that RA complications are lower in the present era.
Dr. Janet Pope is Professor of Medicine at Western University and Division Head of Rheumatology. Dr. Pope's research interests include epidemiologic studies in scleroderma, classification criteria in systemic sclerosis, systemic lupus erythematosus and rheumatoid arthritis.View Full Bio