title: Acute axis fractures. Analysis of management and outcome in 340 consecutive cases.
abstract: METHODS
  Retrospective review of acute axis fractures treated at a tertiary referral center.
  
  
  OBJECTIVE
  To determine the optimal treatment of axis fractures based on 340 cases from a single institution.
  
  
  BACKGROUND
  Axis fractures account for almost 20% of acute cervical spine fractures. However, their management and the clinical criteria predictive of nonoperative failure remain unclear.
  
  
  METHODS
  Admission imaging studies and clinical variables were obtained for 340 consecutive axis fracture patients. Fractures were classified as as odontoid Type I, II, or III with dena displacement on admission roentgenograms; hangman's fractures of Francis grade and Effendi type; and miscellaneous fractures. Treatment methods were documented, and outcomes were based on dynamic lateral roentgenograms, clinical examination, or telephone interviews at last follow-up.
  
  
  RESULTS
  Follow-up data were available in 92% of cases. Type II odontoid fractures comprised 35% of all axis fractures, were the most difficult to treat, and had the highest nonunion rate (28.4%). Odontoid displacement of 6 mm or more was associated with Type II nonunion (chi-square = 33.74, P < 0.0001). Patients underwent surgical fusion if fracture alignment could not be maintained by an external orthosis, or if they had odontoid fractures with transverse ligament disruption, Type II odontoid fractures with dens displacement of at least 6 mm, or hangman's fractures of severe Francis grade or Effendi type.
  
  
  CONCLUSIONS
  Type II odontoid fractures have the highest nonunion rate and were associated with dens displacement of 6 mm or greater. Early surgical fusion is recommended for acute fracture instability despite external immobilization, transverse ligament disruption, Type II odontoid fractures with dens displacement of at least 6 mm on admission, or severe Francis grade or Effendi-type hangman's fractures. Otherwise, nonoperative management is sufficient.
authors.affiliation: Division of Neurological Surgery, Barrow Neurological Institute, Mercy Healthcare Arizona, Phoenix, USA.
authors.forename: K A
authors.initials: KA
authors.lastname: Greene
authors.forename: C A
authors.initials: CA
authors.lastname: Dickman
authors.forename: F F
authors.initials: FF
authors.lastname: Marciano
authors.forename: J B
authors.initials: JB
authors.lastname: Drabier
authors.forename: M N
authors.initials: MN
authors.lastname: Hadley
authors.forename: V K
authors.initials: VK
authors.lastname: Sonntag
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001368:Axis, Cervical Vertebra / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery; D001930:Brain Injuries / Q000150:complications; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D005592:Fracture Fixation / Q000379:methods*; D005599:Fractures, Ununited; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012189:Retrospective Studies; D016103:Spinal Fractures / Q000000981:diagnostic imaging / Q000401:mortality / Q000628:therapy*; D013124:Spinal Injuries / Q000150:complications; D016896:Treatment Outcome