title: Atlanto-axial subluxation as the initial manifestation of spondyloarthritis.
abstract: Patients with spondyloarthritis (SpA) typically present with inflammatory back pain, peripheral arthritis and enthesitis, often with distinctive clinical features such as psoriasis and inflammatory bowel diseases. Atlanto-axial subluxation (AAS) is a complication occurring rarely in these patients, and usually is seen in patients with longstanding, severe disease. We present three cases of AAS whose initial presentation of AAS was followed by subsequent development of signs and symptoms meeting the European Spondyloarthropathy Study Group (ESSG) classification criteria for SpA. All three patients were less than 30 years of age and had no other explanation for the AAS. Significantly, all three patients required C1/C2 surgical fusion within 1 year of symptom onset due to severe pain, though none of them developed neurologic complications related to AAS such as myelopathy. Peripheral arthritis/tendonitis, the presence of HLA-B27 gene and family history of SpA appeared to be associated with higher risk of evolution to SpA in these patients. No medical therapy has been systematically examined in this condition.
authors.affiliation: Department of Rheumatology and Immunology, Singapore General Hospital (SGH), Singapore.
authors.forename: Nai Lee
authors.initials: NL
authors.lastname: Lui
authors.forename: Robert D
authors.initials: RD
authors.lastname: Inman
mesh_terms: D000293:Adolescent; D000328:Adult; D001268:Atlanto-Axial Joint / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D005260:Female; D006801:Humans; D004204:Joint Dislocations / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D008297:Male; D010146:Pain; D013122:Spinal Diseases / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D013123:Spinal Fusion; D013167:Spondylitis, Ankylosing / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D055815:Young Adult