Rheumatoid arthritis (RA) is the most common inflammatory disorder affecting the cervical spine. The purpose of this study was to characterize the atloaxial involvement with magnetic resonance imaging (MRI) in patients with early RA at the moment of diagnosis and after 18 months of a tight control therapy.
Twenty consecutive patients with early RA without cervical symptoms and 20 healthy controls were enrolled. The patients underwent unenhanced and enhanced gadolinium MRI study of the upper cervical spine at diagnosis and after 18 months of therapy. The presence of pannus tissue at MRI was considered active synovitis.
Five (25%) of the 20 patients presented craniocervical involvement with active synovitis at MRI. At onset, patients with cervical involvement presented higher levels of erythrocyte sedimentation rate, a higher swollen joint count, and a higher Disease Activity Score in 44 joints level. All 5 patients (100%) with cervical involvement presented already peripheral erosions. After 18 months, 1 of 5 patients with atloepistrophic synovial involvement at baseline presented complete regression of the enhancement of synovial periodontoid process, and 1 presented a decrease of this enhancement. None of the patients developed erosive process at the odontoid. The only patient with complete regression of the enhancement presented a very early disease (<3 months).
Our study demonstrates involvement of the atloaxial junction in 25% of early RA patients, in particular in patients with active and erosive arthritis. An early diagnosis and aggressive treatment with a combination therapy, aiming for remission, does not always reduce atlantoaxial synovitis.