Prevalence of cervical spine subluxations and dislocations in a community-based rheumatoid arthritis population.

The prevalence of rheumatoid cervical spine subluxations was studied by plain radiography in a population of 13,000 adults with 98 out of 103 detected cases of rheumatoid arthritis. Anterior atlantoaxial subluxation (AAS) of 4 mm or more was found in 33% of the cases and vertical dislocation in 14% or 27% depending on the diagnostic method. Lateral, posterior and subaxial subluxations were found in 14%, 2% and 21% respectively. These figures agree with former findings in clinical populations. One patient had been operated on for subaxial subluxation. Anterior AAS of 9 mm or more was found in four cases, subaxial subluxation of more than 4 mm in one case and a combination of anterior AAS of 6-9 mm and vertical dislocation in six cases. If these limits are taken as indications for surgery, as recommended earlier, about 10% of the RA patients should be operated, an unrealistic figure. It is concluded that intolerable pain or cervical myelopathy, and not the plain radiological findings alone, are indications for surgery. Most cases are treated by conservative methods.