title: A congenital anomaly of the atlas as a diagnostic dilemma: a case report.
abstract: OBJECTIVE
  The purpose of this case report is to draw attention to the differences between a Jefferson fracture and a congenital anomaly of the anterior and/or the posterior arch of the atlas.
  
  
  METHODS
  A 42-year-old woman visited the chiropractic practice complaining of headache, neck pain, dizziness, and numbness in both of her arms after she fell vertically and directly on her head twice on a playground. Before this fall, she had no such complaints. After taking x-rays of the cervical spine, a Jefferson fracture was suspected.
  
  
  RESULTS
  After computed tomography and magnetic resonance imaging scanning, the patient was diagnosed with a congenital anomaly that looked very similar to a Jefferson fracture. After instability of the cervical spine was excluded by the neurosurgeon, chiropractic treatment was delivered. After 6 treatments, the complaints were significantly reduced.
  
  
  CONCLUSIONS
  It is important to be familiar with the differences between a congenital anomaly of the atlas and a Jefferson fracture and to exclude instability of the upper cervical spine before treatment is started.
authors.affiliation: Praktijk Chiropractie Heiloo, Kennemerstraatweg 69, 1851 BB Heiloo, The Netherlands. info@roosenberg.nl
authors.forename: Annemarie
authors.initials: A
authors.lastname: de Zoete
authors.forename: Ursula A
authors.initials: UA
authors.lastname: Langeveld
mesh_terms: D000328:Adult; D001270:Cervical Atlas / Q000002:abnormalities* / Q000000981:diagnostic imaging* / Q000293:injuries; D002574:Cervical Vertebrae / Q000002:abnormalities* / Q000000981:diagnostic imaging* / Q000293:injuries; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D026882:Manipulation, Chiropractic / Q000379:methods; D019838:Neck Injuries / Q000175:diagnosis; D011859:Radiography; D016103:Spinal Fractures / Q000175:diagnosis; D016896:Treatment Outcome