title: Treatment modality in type II odontoid fractures defines the outcome in elderly patients.
abstract: BACKGROUND
  Odontoid fractures account for approximately 20% of all fractures of the cervical spine. They represent the most common cervical spine injury for patients older than 70 years, the majority being type II fractures (65-74%), which are considered to be relatively unstable. The management of these fractures is controversial. Possible treatment options are either conservative or surgical. Surgical procedures include either anterior screw fixation of the odontoid or posterior C1/C2 fusion. The aim of this study was to compare the outcome of the three treatment modalities in elderly patients.
  
  
  METHODS
  Between June 2004 and February 2010, all patients older than 65 years (n = 47) with type II fractures of the odontoid according to the Anderson and D'Alonso classification were retrospectively reviewed.
  
  
  RESULTS
  In the non-operatively managed cohort, 11 patients (79%) died postoperatively within a mean period of 23 months. In all other cases (n = 3), radiographs demonstrated non-union. The mean lateral displacement was 1.9 mm (range 0-5,8 mm) and a mean angulation of 29,1° (range 0-55°) was found.Anterior screw fixation was carried out in 17 patients. The non-union rate in this cohort was 77%. In patients with a posterior C1-C2 fusion, a bony fusion of the posterior elements was found in 15 of 16 cases (93%). Survival rates were significantly higher among the group of patients who were treated with anterior screw fixation or posterior C1/C2 fusion compared to the conservatively treated group.
  
  
  CONCLUSIONS
  We found the best clinical results with low rates of non-union as well as low mortality rates following posterior C1/C2 fusion making this our treatment of choice especially in an elderly patient collective.
authors.affiliation: Department of Surgery, Division of Trauma Surgery, University Hospital Zurich, Zurich, Switzerland. maxjscheyerer@gmx.ch.
authors.forename: Max J
authors.initials: MJ
authors.lastname: Scheyerer
authors.forename: Stefan M
authors.initials: SM
authors.lastname: Zimmermann
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Simmen
authors.forename: Guido A
authors.initials: GA
authors.lastname: Wanner
authors.forename: Clément Ml
authors.initials: CM
authors.lastname: Werner
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001863:Bone Screws; D005260:Female; D005500:Follow-Up Studies; D005593:Fracture Fixation, Internal / Q000295:instrumentation; D006801:Humans; D008297:Male; D009809:Odontoid Process / Q000293:injuries* / Q000601:surgery; D009989:Orthotic Devices; D012189:Retrospective Studies; D016103:Spinal Fractures / Q000401:mortality / Q000601:surgery / Q000628:therapy*; D013123:Spinal Fusion; D016896:Treatment Outcome