title: C1-C2 fracture-dislocations in children and adolescents.
abstract: OBJECTIVE
  C1-C2 is the predominant level of cervical spine injuries in children and adolescents. Either a fracture of the dens or atlantoaxial dislocation (AAD) without fracture of the dens can occur. We present a number of cases to compare their clinical presentations and discuss the preferred method of treatment.
  
  
  METHODS
  There were 12 cases of type II odontoid fracture and 10 cases of AAD without fracture over a 13-year period. There was a male predominance and traffic collisions were the major cause of injury. Two thirds of the dens fractures were in children over 13 years of age and seven out of ten dislocations without fracture were under 13 years of age. Eight patients with fractured dens suffered from spinal cord injuries but six of those with dislocations were neurologically intact. Two patients of fractured dens and one with AAD presented with chronic myelopathies because of undetected injuries.
  
  
  RESULTS
  Three patients expired because of irreversible respiratory failure. Most of the fractured dens achieved bony union after 3 months of halo-vest immobilization but those patients with AAD without fracture usually needed a fusion procedure. Transoral decompression was performed in two cases of dens fracture malunion. All of the survivors of the dens fracture returned to normal or independent daily living. Six of the AAD patients returned to normal, one had a mild neural deficit, and one had persistent spastic quadriparesis.
  
  
  CONCLUSIONS
  There is a higher incidence of atlantoaxial dislocation without fracture in children under 13 years of age and a higher incidence of dens fractures in those over 13 years of age. Those with fractures of the dens are more likely to present with evidence of neural injury while those with AAD are more likely to be neurologically intact; however, a correct diagnosis and proper management are mandatory to prevent chronic myelopathy. Halo-vest immobilization is sufficient for most fractures of the dens in children, with AAD usually requiring a fusion.
authors.affiliation: Department of Neurosurgery, Chang Gung Medical College and Memorial Hospital, Taoyuan, Taiwan, Republic of China.
authors.forename: T N
authors.initials: TN
authors.lastname: Lui
authors.forename: S T
authors.initials: ST
authors.lastname: Lee
authors.forename: C W
authors.initials: CW
authors.lastname: Wong
authors.forename: Y S
authors.initials: YS
authors.lastname: Yeh
authors.forename: W C
authors.initials: WC
authors.lastname: Tzaan
authors.forename: T Y
authors.initials: TY
authors.lastname: Chen
authors.forename: S Y
authors.initials: SY
authors.lastname: Hung
mesh_terms: D000293:Adolescent; D001268:Atlanto-Axial Joint / Q000293:injuries*; D002574:Cervical Vertebrae / Q000293:injuries*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005592:Fracture Fixation; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D004204:Joint Dislocations / Q000000981:diagnostic imaging / Q000628:therapy; D008297:Male; D009989:Orthotic Devices; D011859:Radiography; D012189:Retrospective Studies; D016103:Spinal Fractures / Q000000981:diagnostic imaging / Q000628:therapy; D013123:Spinal Fusion; D016896:Treatment Outcome