Abstract
Pseudotumor of the preodontoid soft tissue seen on magnetic resonance imaging (MRI) is a well known manifestation of atlantoaxial subluxation with rheumatoid arthritis (RA). We report a case of atlantoaxial dislocation pseudotumor with RA reduced remarkably three weeks after posterior fixation. The patient was a 55-year-old male with RA for 10 years. Onset of numbness in the arms and legs dated back to three months before. He was referred from a private M.D. for gradual gait disturbance. His RA stage was classified as stage 3 and class 3. Lateral flexion radiographs showed ADI 14 mm, SAC 12 mm. extension led to reduction. Compression of the medulla and upper cervical spine, due to periodontoid pannus (pseudotumor) extending into the spinal canal, was seen in MRI. Bone resorption most likely caused by geodes was found at the base of odontoid by computed tomography. We performed posterior atlantoaxial fixation. Neck pain and cervical myelopathy improved. His Ranawat neurological score also improved to 2 from 3A. Post three weeks operative MRI showed a significant decrease of the pseudotumor.
