Clinical diagnosis of atlanto-axial joint involvement in patients with rheumatoid arthritis

Objective To investigate the clinical manifestations, laboratory tests, and image modalities on rheumatoid arthritis (RA) accompanied with atlanto-axial joint involvement. Methods Sixty-four cases of RA accompanied with cervical vertebra involvement were divided into 2 groups by lesion location. Twenty-two cases were RA accompanied with atlanto-axial joint involvement, while 42 cases were RA with cervical vertebra other than atlanto-axial joint involvement. The age, course, clinical manifestations and the lab results were compared between the two groups by t test, Chi-square test and Fisher's exact probability. The X-ray, CT and magnetic resonance imaging (MRI) for cervical vertebra were analyzed in RA with atlanto-axial joint invo-lvement. Results Compared with non-atlantoaxial cervical group, the disease course [(15±10) years vs (8±9) years, t=3.030, P=0.004], upper cervical vertebra pain (73% vs 7%, χ2=29.75, P<0.01), lower cervical vertebra pain (9% vs 40%, χ2=6.813, P=0.009), cervical activity limitation (68% vs 14%, χ2=19.023, P<0.01), upper cervical vertebra pressing pain (100% vs 7%, χ2=52.297, P<0.01), lower cervical vertebra pressing pain (9% vs 60%, χ2=15.056, P<0.01) and erythrocyte sedimentation rate (ESR) [(73±34) mm/1 h vs (53±37) mm/1 h, t=2.039, P=0.046)] were significantly different in atlantoaxial joint lesions group. CT combined with MRI exams had high diagnostic value in RA with atlanto-axial joint involvement. CT scan had the conformed diagnostic value. Sixteen cases were positive (73%) by MRI scan, while 3 cases (14%) by X-ray. Conclusion Timely CT scan and/or MRI scan for RA patients with neck pain in upper cervical vertebra, long disease course, cervical activity limitation and high ESR are helpful for early diagnosis of atlanto-axial joint involvement. Key words: Arthritis, rheumatoid; Atlanto-axial joint; Tomography, X-ray; Tomography spiral computed; Magnetic resonance imaging