title: Positioning study of cervical vertebra pedicle axial line projective point by computed tomography image reconstruction.
abstract: BACKGROUND
  Safe placement of the screws is a critical aspect of trans-pedicle internal fixation, and little information on in vivo morphology of the cervical vertebrae pedicle measured with imaging methods is available. The aim of this study was to measure the dimensions of cervical vertebrae C3 to C7 and provide screw length, screw diameter and tilt angle for clinical cervical vertebra trans-pedicle internal fixation.
  
  
  METHODS
  Thirty Chinese men and women underwent high-speed spiral computed tomography measurements to obtain data for C3 to C7, and the morphology of the cervical vertebra pedicles was reconstructed.
  
  
  RESULTS
  Reconstructed computer tomography image data revealed that: (1) pedicle sponge width increased incrementally from C3 to C7, (2) pedicle depth was similar for C3 to C7, (3) pedicle angle decreased incrementally from 47.20° to 33.76° for C3 to C7, and (4) pedicle point to midline distance was similar for C3 to C7. There were no statistical differences in morphological data between the right and the left side. Men had statistically larger values than women for all morphological parameters.
  
  
  CONCLUSIONS
  Reconstructed computed tomography images can provide useful data for clinical cervical vertebra trans-pedicle internal fixation. The individual measurement of cervical vertebra pedicles is recommended for safe placement of trans-vertebra pedicle screws.
authors.affiliation: Trauma and Orthopaedics Department, Peking University People's Hospital, Beijing 100044, China.
authors.forename: Pei-Xun
authors.initials: PX
authors.lastname: Zhang
authors.forename: Feng
authors.initials: F
authors.lastname: Xue
authors.forename: Dian-Ying
authors.initials: DY
authors.lastname: Zhang
authors.forename: Zhong-Guo
authors.initials: ZG
authors.lastname: Fu
authors.forename: Na
authors.initials: N
authors.lastname: Han
authors.forename: Yu-Hui
authors.initials: YH
authors.lastname: Kou
authors.forename: Bao-Guo
authors.initials: BG
authors.lastname: Jiang
mesh_terms: D000328:Adult; D001863:Bone Screws; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging* / Q000601:surgery*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016268:Internal Fixators; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult