title: Efficacy of anterior odontoid screw fixation in elderly patients with Type II odontoid fractures.
abstract: OBJECTIVE
  Type II odontoid fractures are the most common trauma-related dens fracture. Although Type III odontoid fractures have a high union rate when external immobilization is applied, Type II fractures are associated with high rates of nonunion, particularly in elderly patients and those with posteriorly displaced fractures or fractures displaced by more than 6 mm. Because elderly patients may not also tolerate external immobilization in a halo vest, alternative techniques should be explored to identify a method for managing these higher-risk patients. In this study the authors examine the efficacy of anterior odontoid screw fixation in a high-risk group of 10 elderly patients (> 65 years of age) treated for Type II odontoid fractures.
  
  
  METHODS
  A retrospective review of all patients with Type II odontoid fractures treated at two institutions between September 1997 and March 2000 was performed. Demographic data, neurological examination, fracture type and degree of displacement, treatment method, and outcome data were examined at discharge. Ten patients older than 65 years who had sustained a trauma-related odontoid fracture and had undergone an anterior odontoid screw placement procedure were retrospectively reviewed. Fracture displacement (mean 6.6 mm) was observed in all but one patient, and in seven there were posteriorly displaced fractures. Seven were successfully treated with anterior screw fixation and external orthosis alone; in one patient in whom poor intraoperative screw purchase had been observed, the fracture healed after undergoing halo vest therapy. Only one patient was shown to develop a nonunion requiring a subsequent posterior fusion procedure.
  
  
  CONCLUSIONS
  Odontoid screw fixation can be safely performed in elderly patients, and frequent bone union is demonstrated. However, osteopenia may preclude adequate screw fixation in some patients.
authors.affiliation: Department of Neurosurgery, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, USA. EJHarrop@aol.com
authors.forename: J S
authors.initials: JS
authors.lastname: Harrop
authors.forename: G J
authors.initials: GJ
authors.lastname: Przybylski
authors.forename: A R
authors.initials: AR
authors.lastname: Vaccaro
authors.forename: K
authors.initials: K
authors.lastname: Yalamanchili
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001863:Bone Screws; D005260:Female; D005500:Follow-Up Studies; D005593:Fracture Fixation, Internal / Q000523:psychology*; D006801:Humans; D008297:Male; D009809:Odontoid Process / Q000293:injuries* / Q000601:surgery*; D016103:Spinal Fractures / Q000601:surgery*; D013123:Spinal Fusion; D016896:Treatment Outcome