title: Anatomical considerations for cervical pedicle screw insertion: the use of multiplanar computerized tomography reconstruction measurements.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the linear and angular parameters of the vertebral body (VB) required for cervical pedicle screw (CPS) insertion by using multiplanar computerized tomography (CT) reconstructions.
  
  
  METHODS
  Three hundred fifteen vertebrae from C-3 to C-7 in 63 patients were studied. Pedicle dimensions such as pedicle transverse angle (PTA), pedicle sagittal angle (PSA), and pedicle outer width (POW) were measured on axial CT reconstructions, as were linear parameters including the lateral mass thickness (LMT), the anteroposterior (AP) and mediolateral distances between spinal canal and transverse foramen, and spinal canal longitudinal and transverse diameter. In addition, the correlations between PTA and other parameters were calculated using univariate linear regression analysis. The overall mean LMT ranged from 10.7 to 12.6 mm. The smallest mean AP spinal canal-transverse foramen distance was found at C-7 (1.1 mm),whereas the largest mean distance was at C-4 (3.1 mm). The smallest mean mediolateral spinal canal-transverse foramen distance was found at C-4 (1.2 mm), whereas the largest mean distance was at C-7 (4.7 mm). There were significant intergroup differences between male and female patients except for PTA and spinal canal longitudinal diameter. The PTA had a direct linear correlation with AP and mediolateral spinal canal-transverse foramen distances. The largest Pearson coefficient was 0.71 between the PTA and AP spinal canal-transverse foramen distance and the inverse one was -0.73 between the PTA and mediolateral spinal canal-transverse foramen distance.
  
  
  CONCLUSIONS
  Analysis of the data obtained in this study suggests that not only pedicle dimensions but also linear and angular parameters of the VB can be useful data when inserting a CPS.
authors.affiliation: Department of Orthopaedic Surgery, Jikei University School of Medicine, Tokyo, Japan. chazono@jikei.ac.jp
authors.forename: Masaaki
authors.initials: M
authors.lastname: Chazono
authors.forename: Shigeru
authors.initials: S
authors.lastname: Soshi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Inoue
authors.forename: Yoshikuni
authors.initials: Y
authors.lastname: Kida
authors.forename: Chikara
authors.initials: C
authors.lastname: Ushiku
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001837:Body Weights and Measures; D001863:Bone Screws; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures; D012737:Sex Factors; D013122:Spinal Diseases / Q000000981:diagnostic imaging* / Q000601:surgery*; D014057:Tomography, X-Ray Computed