Upper cervical instability associated with rheumatoid arthritis: a case report.

Rheumatoid arthritis (RA) affects between 1 and 2 million individuals in the United States. Atlantoaxial instability (AAI) has been shown to have 40-85% prevalence among individuals with RA. Despite the high incidence of craniovertebral involvement, overt symptoms of instability are rare. The high risk of AAI and limited symptomology should increase therapist suspicion of potential contraindications and precautions to initiation of therapy for the cervical spine without prior diagnostic imaging. The purpose of this case study is to describe the historical, clinical, and diagnostic imaging complexity of AAI associated with RA, and to illustrate the use of these factors in the clinical reasoning within a patient case.