title: Axis instrumentation: surgical results.
abstract: OBJECTIVE
  Evaluate the surgical results of axis screw instrumentation.
  
  
  METHODS
  Retrospective evaluation of the clinical and radiological data of patients submitted to axis fixation using screws.
  
  
  RESULTS
  Seventeen patients were surgically treated. The mean age was 41.8 years (range: 12-73). Spinal cord trauma was the most common cause of instability (8 patients - 47%). Bilateral axis fixation was performed in all cases, except one, with laminar screw (total of 33 axis screws). Seven patients (41.1%) underwent bilateral pars screws; laminar screws were used in six cases and pedicular screws were used in two. In two cases, we performed a hybrid construction (laminar + pars and pedicle + pars). There was no neurological worsening or death, nor complications directly related to use axis screws.
  
  
  CONCLUSIONS
  Axis instrumentation was effective and safe, regardless of the technique used for stabilization. Based on our learnt experience, we proposed an algorithm to choose the best technique for axis screw fixation.
authors.affiliation: Universidade Estadual de Campinas UNICAMP, Campinas SP, Brazil. andjoaquim@yahoo.com
authors.forename: Andrei F
authors.initials: AF
authors.lastname: Joaquim
authors.forename: Enrico
authors.initials: E
authors.lastname: Ghizoni
authors.forename: Diogo V
authors.initials: DV
authors.lastname: Anderle
authors.forename: Evandro de
authors.initials: Ed
authors.lastname: Oliveira
authors.forename: Helder
authors.initials: H
authors.lastname: Tedeschi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000465:Algorithms; D001368:Axis, Cervical Vertebra / Q000601:surgery*; D001863:Bone Screws; D002648:Child; D005500:Follow-Up Studies; D006801:Humans; D007593:Joint Instability / Q000601:surgery; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013119:Spinal Cord Injuries / Q000601:surgery; D013123:Spinal Fusion / Q000295:instrumentation*; D055815:Young Adult