title: Morphometry of typical cervical vertebrae on dry bones and CT scan and its implications in transpedicular screw placement surgery.
abstract: BACKGROUND
  Transpedicular stabilization of subaxial cervical spine is a very delicate procedure that requires thorough understanding of the pedicle anatomy to minimize the rate of neurovascular complications. The current study was conducted to investigate the morphometric details including dimensions and axis of typical cervical vertebrae (C3-C6) for transpedicular screw insertion surgery.
  
  
  METHODS
  The current study was conducted on 100 sides of 50 dry and 160 sides of 80 vertebrae on computerized tomography scans of typical cervical vertebrae. Parameters that were studied bilaterally included distance between medial aspect of the pedicle and dural sac, pedicle height, pedicle width, interpedicular distance, lateral and medial cortical thickness, transverse pedicle angle and chord length.
  
  
  RESULTS
  Distance between medial aspect of the pedicle and dural sac was found to be 2.2 ± 0.99 mm. Mean pedicle height (6.5 ± 1.1 mm) was found to be greater than pedicle width (4.9 ± 0.9 mm) in all the vertebrae. Mean transverse pedicle angle and chord length was observed to be 39.4° and 32.1 mm, respectively. Mean interpedicular distance, medial and lateral cortical thickness was observed to be 21.8 ± 1.6, 1.43 ± 0.4 and 0.79 ± 0.2 mm, respectively.
  
  
  CONCLUSIONS
  The present study highlights a three-dimensional orientation of subaxial cervical pedicle anatomy, while emphasizing the risks involved in the view of comparatively smaller values of pedicle dimensions of subaxial cervical vertebrae. This knowledge about typical cervical vertebrae, its pedicle and their adjacent neurovascular structures may enhance the safety of transpedicular screw insertion.
authors.affiliation: Department of Anatomy, PGIMER, Government Medical College and Hospital, Sector-32, Chandigarh, India. richagpt7@gmail.com
authors.forename: Richa
authors.initials: R
authors.lastname: Gupta
authors.forename: Kanchan
authors.initials: K
authors.lastname: Kapoor
authors.forename: Anshu
authors.initials: A
authors.lastname: Sharma
authors.forename: Suman
authors.initials: S
authors.lastname: Kochhar
authors.forename: Rajeev
authors.initials: R
authors.lastname: Garg
mesh_terms: D001863:Bone Screws; D002574:Cervical Vertebrae / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008297:Male; D019637:Orthopedic Procedures; D012016:Reference Values; D014057:Tomography, X-Ray Computed