title: Outcomes of surgery for unstable odontoid fractures combined with instability of adjacent segments.
abstract: BACKGROUND
  At present, traumatic atlantoaxial dislocation or C2-3 instability complicating odontoid fractures remains rarely reported. The aim of this study was to further investigate the surgical treatment strategies and curative effects for odontoid fractures combined with instability of adjacent segments.
  
  
  METHODS
  This is a retrospective study of 12 patients (5 females and 7 males; age, 21-65 years) who underwent internal fixation for odontoid fractures (type II and shallow type III) and atlantoaxial instability in 6 cases, C2-3 instability in 4 cases, simultaneous C1-2 and C2-3 instability in 2 cases between January 2005 and June 2012. Accordingly, individualized surgeries were performed. Fracture healing and bone fusion were determined on X-ray scan. Upper limbs, lower limbs and sphincter functions were assessed using the Japanese Orthopaedic Association (JOA) score. Frankel grading system was used for the evaluation of neurological situation.
  
  
  RESULTS
  Mean follow-up time of all 12 cases was 16.4 months (range, 12 to 48 months). Odontoid fracture healing was obtained in all patients within 9 months, and graft fusion was achieved within 6 months. JOA score was significantly improved from 6.3 ± 3.1 preoperatively to 11.1 ± 4.6 at 12 months after operation (P = 0.007), with 50.5 ± 25.7% recovery rate and 66.7% excellent and good rate. Except one patient still had Frankel grade B neurological injury at 12 months after surgery, the other patients improved their neurological situation (at 1 grade in Frankel scale). One patient developed wound fat liquefaction which resolved by changing the dressing. Cerebrospinal fluid leakage occurred in three patients, which resolved after the continuous drainage for 2 days.
  
  
  CONCLUSIONS
  According to the characteristics of odontoid fractures, the individualized operative procedure should be performed, resulting in high fracture healing rate, function recovery rate, and less, transient complications.
authors.affiliation: Department of Orthopedics, Shanghai Jiaotong University Affiliated the first people's Hospital, No,1878 North Sichuan Road, Shanghai 200080, China. wangleikimi@hotmail.com.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Chao
authors.initials: C
authors.lastname: Liu
authors.forename: Qing-Hua
authors.initials: QH
authors.lastname: Zhao
authors.forename: Ji-Wei
authors.initials: JW
authors.lastname: Tian
mesh_terms: D000328:Adult; D000368:Aged; D001268:Atlanto-Axial Joint / Q000293:injuries* / Q000601:surgery; D005260:Female; D005593:Fracture Fixation, Internal; D017102:Fracture Healing; D006801:Humans; D004204:Joint Dislocations / Q000601:surgery*; D007593:Joint Instability / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009809:Odontoid Process / Q000293:injuries* / Q000601:surgery; D012189:Retrospective Studies; D016103:Spinal Fractures / Q000601:surgery*; D016896:Treatment Outcome; D055815:Young Adult