High mortality rate in rheumatoid arthritis with subluxation of the cervical spine: a cohort study of operated and nonoperated patients

Abstract

Study design: In a prospective cohort study 532 patients with rheumatoid arthritis (RA) and subluxations of the cervical spine were consecutively collected during 1974-1999.

Objective: The aims of the study were to assess important factors affecting the mortality rate and the timing of surgical intervention.

Summary of background data: The average follow-up time from the first visit to death or to the end of the study was 8.5 (SD, 5.7) years. Of the 217 operated patients 144 (66%) died, and of the 315 nonoperated patients 137 (43%) died.

Methods: Patients were selected for operative intervention based on anterior, vertical and subaxial subluxations, pain, and/or cervical neurology. Survival analyses were used for comparisons between patients with RA and the normal population, and between the operated and those treated conservatively.

Results: The survival rate for all RA patients was significantly reduced when compared with average survival in Norway (P < 0.001). The operated group had a significantly lower survival rate than the nonoperated group. In patients with severe instability of the cervical spine, the defined selection criteria for surgical intervention were specific. By comparison of calculated propensity scores, the operated and nonoperated groups were too different to be directly comparable. After surgery only 11 patients (5%) experienced residual pain in the neck or neurologic symptoms. None of these patients were alive at the end of the study, signifying that residual pain or neurologic symptoms are poor prognostic signs (P = 0.015). In the operated group, anterior subluxation and vertical settling greater than the lower indication limits did not have a significant influence on the survival rate, but there was a reduced survival for patients with subaxial subluxations. A clear association was found between increased vertical settling and sudden death.

Conclusion: RA with neck involvement is a progressive and serious condition with reduced lifetime expectancy. Hence, our interpretation is that operative intervention improves local symptoms and most likely changes the condition from worse to better by increasing lifetime expectancy in high risk patients. Since the per- and postoperative complications are few, a changed attitude toward more liberal indications for earlier surgery may reduce the symptoms and the mortality rate even more.