[Contribution of dynamic radiographs in atlantoaxial subluxation in rheumatoid arthritis]

Cervical spine (CS) involvement is common during rheumatoid arthritis (RA) and it is distinguished by its potential gravity.

To determinate the occurrence of atlantoaxial subluxation (AAS) by dynamic incidences X-Ray and to assess its predictive factors.

Our study included a cohort of 40 patients carrying RA, who fulfilled the American College of Rheumatology criteria, for more than 2 years. All patients had a complete physical and laboratory evaluation. Radiological evaluation included CS radiographs in anteroposterior, lateral, and lateral in full flexion and extension views.

The occurrence of CS involvement was about 47.5% by XRay dominated by AAS which found in 42,5% of the cases. Among AAS, anterior AAS was the most frequent with a prevalence of 22,5% followed by lateral AAS in 12,5% then vertical and rotatory AAS in 10% of cases each one and posterior AAS in 2,5% of the cases. Comparison between patients with and without CS involvement indicated the presence of two predictive factors: the sharp modified score and the C - reactive protein (p=0.002 and p=0.004 respectively).

Our study demonstrated that AAS is frequent in RA particularly in active forms with structural lesions. AAS can be asymptomatic, for this reason systematic diagnosis by X-Ray with dynamic views is important.