title: Posterior atlanto-axial arthrodesis for fixation of odontoid nonunions.
abstract: METHODS
  A retrospective case series.
  
  
  OBJECTIVE
  To determine the clinical and radiographic long-term results after posterior atlanto-axial arthrodesis of odontoid nonunions.
  
  
  BACKGROUND
  Nonunion of odontoid fractures is a relatively common and dreaded complication after surgical and nonoperative treatment of these injuries. Although there might be a significant rate, which require surgical stabilization due to atlanto-axial instability, only few publications have covered this issue and presented reliable long-term results.
  
  
  METHODS
  We retrospectively analyzed the clinical and radiographic records of 9 (4 women and 5 men) patients with an average age of 68 (42-78) years at the time of injury who had undergone posterior atlanto-axial arthrodesis for surgical treatment of odontoid nonunions between 1988 and 2004. For posterior atlanto-axial arthrodesis, we performed either C1-C2 transarticular screw fixation, or posterior wiring and bone grafting, or a combination of these 2 techniques.
  
  
  RESULTS
  Eight patients achieved a satisfactory clinical outcome and returned to their preinjury activity level. The Smiley-Webster scale showed an overall functional outcome score of 2.2, which was 0.9 points superior to the outcome score before surgery. Neurologic deficits after operative treatment of the odontoid nonunion were evaluated in 2 patients. In all the other patients with primary neurologic deficits or delayed neurologic sequelae we saw a full recovery. Solid bony fusion of the cervical arthrodesis was achieved in all of the patients. Failures of reduction or fixation were noted in 2 patients, but no reoperations were necessary.
  
  
  CONCLUSIONS
  In summary, we had a satisfactory outcome after surgical treatment of odontoid nonunions in patients with atlanto-axial instability and severe motion pain at the cervical spine. With a bony union rate of 100% and a noticeable improvement of clinical results and neurologic function, posterior atlanto-axial arthrodesis seems to be an appropriate option for nonunited odontoid fractures that require surgical stabilization.
authors.affiliation: Department of Traumatology, Medical University of Vienna, Waehringer Guertel, Vienna, Austria. patrick.platzer@gmx.at
authors.forename: Patrick
authors.initials: P
authors.lastname: Platzer
authors.forename: Vilmos
authors.initials: V
authors.lastname: Vécsei
authors.forename: Gerhild
authors.initials: G
authors.lastname: Thalhammer
authors.forename: Gerhard
authors.initials: G
authors.lastname: Oberleitner
authors.forename: Mark
authors.initials: M
authors.lastname: Schurz
authors.forename: Christian
authors.initials: C
authors.lastname: Gaebler
mesh_terms: D000328:Adult; D000368:Aged; D001174:Arthrodesis / Q000295:instrumentation / Q000379:methods; D001268:Atlanto-Axial Joint / Q000000981:diagnostic imaging / Q000601:surgery; D001270:Cervical Atlas / Q000000981:diagnostic imaging / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016268:Internal Fixators; D008297:Male; D008875:Middle Aged; D009809:Odontoid Process / Q000000981:diagnostic imaging / Q000601:surgery*; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000601:surgery; D011446:Prospective Studies; D011859:Radiography; D012086:Reoperation; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000295:instrumentation* / Q000379:methods*; D017211:Treatment Failure