title: Redislocation in a halo vest of an atlanto-occipital dislocation in a child: recommendations for treatment.
abstract: METHODS
  A case of a child with a traumatic atlanto-occipital dislocation (AOD), with unexpected secondary redislocation in a halo vest is presented. An extensive literature review was performed.
  
  
  OBJECTIVE
  To show the difficulties in diagnosing AOD, to emphasize its intrinsic instability, and to make recommendations for treatment of this condition.
  
  
  BACKGROUND
  AOD is a rare condition that is difficult to diagnose. Because of the high neurologic morbidity, this injury often results in death. Different diagnostic approaches have been evaluated throughout the literature. Also, there are different opinions on how to treat AOD. There is no large trial that compares conservative treatment with surgery.
  
  
  METHODS
  A 4-year-old child with a longitudinal distraction of the head is described. Because of his tenuous medical condition, initial treatment was in a halo vest. However, redislocation occurred inside the vest, so surgical stabilization was performed as soon as the patient's condition allowed.
  
  
  RESULTS
  To diagnose AOD, different measuring techniques can be applied on a lateral cervical spine radiograph. Using a combination of these tools, the sensitivity of the examination can be increased. There are 3 types of dislocation. Type II, which is a longitudinal distraction, is most unstable. Once confirmed, AOD should be immobilized. This can temporarily be performed with a halo-frame, but our case shows that this does not necessarily provide a stable situation, and early surgical reconstruction should be considered.
  
  
  CONCLUSIONS
  AOD can be an extremely unstable lesion and is difficult to diagnose. Although initial treatment in a halo vest is recommended, redislocation can occur even in the vest. We recommend urgent surgical stabilization.
authors: Department of Orthopaedic Surgery, Radboud University Nijmegen Medical Centre, The Netherlands.
authors: Gerrit J
authors: GJ
authors: van de Pol
authors: Patrick W
authors: PW
authors: Hanlo
authors: F Cumhur
authors: FC
authors: Oner
authors: René M
authors: RM
authors: Castelein
mesh_terms: D001269:Atlanto-Occipital Joint / Q000000981:diagnostic imaging / Q000293:injuries*; D002675:Child, Preschool; D006801:Humans; D004204:Joint Dislocations / Q000000981:diagnostic imaging / Q000601:surgery / Q000628:therapy*; D007593:Joint Instability / Q000000981:diagnostic imaging / Q000601:surgery / Q000628:therapy*; D008297:Male; D009984:Orthopedic Fixation Devices; D011859:Radiography; D013123:Spinal Fusion; D014474:Unconsciousness