title: [The feasibilty study of posterior laminar screw fixation techniques in axis].
abstract: OBJECTIVE
  Observation and measurement were done on axial laminar to get the parameters of morphology in Chinese. To evaluate the possibility of the placement of axial laminar screw.
  
  
  METHODS
  The relative parameters of 28 sets of fresh Chinese adults' axial specimens were measured with a digital caliper, a goniometer and imageology, including the distance from superior and inferior the anchor point of the axial laminar screw to superior margin of the axial laminar, the superior,middle and inferior thickness of axial laminar, the height of axial laminar, the length and the angle of the axial laminar screw trajectory, the distance from the anchor point of the axial laminar screw to hole of vertebral artery and the central point of inferior articular process and so on. The data were statistically analyzed.
  
  
  RESULTS
  The distance from superior and inferior the anchoi point of the axial laminar screw to superior margin of the axial laminar was 4 mm and 8 mm respectively. The superior, middle and inferior thickness of axial laminar was 3.2, 6.7, 5.5 mm respectively. The height of axial laminar was 12.8 mm. The superior and inferior length of axial laminar screw trajectory was 26.2 mm and 25.5 mm respectively.
  
  
  CONCLUSIONS
  It is feasible and reliable for posterior laminar screw fixation techniques of axis in Chinese. C2 laminar screw fixation techniques could be used as a supplementary method for conventional posterior screw fixation techniques of C2.
authors.affiliation: Departmnt of Orthopaedics, Ningbo NO.6 Hospital, Ningbo 315040, Zhejiang, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Hu
authors.forename: Rong-ming
authors.initials: RM
authors.lastname: Xu
authors.forename: Wei-hu
authors.initials: WH
authors.lastname: Ma
authors.forename: Yong-ping
authors.initials: YP
authors.lastname: Ruan
authors.forename: Jian-xiang
authors.initials: JX
authors.lastname: Feng
authors.forename: Hui
authors.initials: H
authors.lastname: Xie
authors.forename: Rong
authors.initials: R
authors.lastname: Lin
mesh_terms: D000328:Adult; D000368:Aged; D001368:Axis, Cervical Vertebra / Q000033:anatomy & histology / Q000601:surgery*; D001863:Bone Screws; D005260:Female; D005593:Fracture Fixation, Internal / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged