Prevalence of Abnormal Anterior and Posterior Atlantodental Interval of Anterior Atlantodental Subluxation in Rheumatoid Arthritis Patients

Rheumatoid arthritis is an abnormal of immune system which affected several systems in the body. Cervical spine is one of the target organs. Patients may represent with neck pain, instability of neck, bony subluxation, spinal cord or brain stem compression, and no symptom in some cases. Cervical spine instability was classified to three types: atlantoaxial subluxation, atlantoaxial impaction and subaxial subluxation. The most common level of cervical spine involvement is C1-2 (atlantoaxial subluxation). Forty seven rheumatoid arthritis patients in Khon Kaen Hospital were recruited. Abnormal anterior atlantodental interval were found in 11 patients (23.4%). None of them showed abnormal posterior atlantodental interval and neurological deficit. There was no significant difference in relation to age, gender, duration to diagnosed, steroid usage, serology of rheumatoid factor and anterior atlantodental subluxation between those with normal & abnormal anterior atlantodental interval. Rheumatoid arthritis patients had tendency to have abnormal anterior atlantodental interval which more frequent than abnormal posterior atlantodental interval. Therefore, we should aware of anterior atlantdental suluxation in rheumatoid arthritis patients.