title: Pedicle morphology in thoracic adolescent idiopathic scoliosis: is pedicle fixation an anatomically viable technique?
abstract: METHODS
  A radiographic study of thoracic pedicle anatomy in a group of adolescent idiopathic scoliosis (AIS) patients.
  
  
  OBJECTIVE
  To investigate the anatomic constraints of the thoracic pedicles and determine whether the local anatomy would routinely allow pedicle screw insertion at every level.
  
  
  BACKGROUND
  In spite of the clinical successes reported with limited thoracic pedicle screw-rod constructs for thoracic AIS, controversy exists as to the safety of this technique.
  
  
  METHODS
  Twenty-nine patients with right thoracic AIS underwent preoperative thoracic CT scans and plain radiographs. Anatomic parameters were measured from T1 to T12.
  
  
  RESULTS
  Information on 512 pedicles was obtained. The transverse width of the pedicles from T1 through T12 ranged from 4.6-8.25 mm. The medial pedicle to lateral rib wall transverse width from T1 through T2 ranged from 12.6 to 17.9 mm. Measured dimensions from the CT scans showed the actual pedicle width to be 1-2 mm larger than would have been predicted from the plain radiographs. Age, Risser grade, curve magnitude, and the amount of segmental axial rotation did not correlate with the morphology or size of the thoracic pedicles investigated. In no case would pedicle morphology have precluded the passage of a pedicle screw.
  
  
  CONCLUSIONS
  Based on the data identified in this group of adolescent patients, it is reasonable to consider pedicle screw insertion at most levels and pedicle-rib fixation at all levels of the thoracic spine during the treatment of thoracic AIS.
authors.affiliation: University of Colorado and Woodridge Orthopedic and Spine Clinic, Wheat Ridge, Colorado 80033, USA.
authors.forename: M F
authors.initials: MF
authors.lastname: O'Brien
authors.forename: L G
authors.initials: LG
authors.lastname: Lenke
authors.forename: S
authors.initials: S
authors.lastname: Mardjetko
authors.forename: T G
authors.initials: TG
authors.lastname: Lowe
authors.forename: Y
authors.initials: Y
authors.lastname: Kong
authors.forename: K
authors.initials: K
authors.lastname: Eck
authors.forename: D
authors.initials: D
authors.lastname: Smith
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D001863:Bone Screws; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D012600:Scoliosis / Q000000981:diagnostic imaging* / Q000601:surgery; D013904:Thoracic Vertebrae / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000601:surgery; D014057:Tomography, X-Ray Computed