Atlantoaxial subluxation.
D001172:Arthritis, Rheumatoid / Q000473:pathology*; D001368:Axis, Cervical Vertebra / Q000473:pathology; D001270:Cervical Atlas / Q000473:pathology; D006801:Humans; D004204:Joint Dislocations / Q000473:pathology*; D011379:Prognosis