title: [Anatomic identification of the location of the pedicle of atlas with the lateral mass of C2 to C4 as the landmark].
abstract: OBJECTIVE
  To study the relevant position of the pedicle of C1 to the lateral mass of C(2-4), set up an identification technique for the entry point decision of C1 pedicle screw by using the lateral mass of C(2-4) as anatomic landmarks.
  
  
  METHODS
  Twenty cadaver specimens were used to measure the distance from the sagittal midline of spine to the medial border, the midpoint and the lateral border of C1 pedicle or the lateral mass of C2, C3 or C4. The anatomic relation between the measurements data of C1 pedicle and that of the lateral masses of the cervical vertebrae were analyzed, and the technique of C1 pedicle screw fixation was established.
  
  
  RESULTS
  The average medial border of the lateral mass of C2, C3 and C4 was 0.37 mm, 0.27 mm and 0.24 mm lateral to that of C1 pedicle, the average midpoint of the lateral mass of C2, C3 and C4 was 1.18 mm, 1.41 mm and 1.74 mm lateral to that of C1 pedicle, and the average lateral border of the lateral mass of C2, C3 and C4 was 1.96 mm, 2.54 mm and 3.24 mm lateral to that of C1 pedicle, respectively.
  
  
  CONCLUSIONS
  There is a steady anatomic location relation between C1 pedicle and the lateral mass of C2, C3 or C4. As well as the lateral mass of C2, the lateral mass of C3 or that of C4 could be convenient anatomic landmarks to determine the location of C1 pedicle and the position of C1 pedicle screw entry point.
authors.affiliation: Department of Orthopaedics, Guangzhou General Hospital of Guangzhou Military Command, Guangzhou 510010, China. maxy1001@sina.com
authors.forename: Xiang-yang
authors.initials: XY
authors.lastname: Ma
authors.forename: Qing-shui
authors.initials: QS
authors.lastname: Yin
authors.forename: Zeng-hui
authors.initials: ZH
authors.lastname: Wu
authors.forename: Hong
authors.initials: H
authors.lastname: Xia
authors.forename: Shi-zhen
authors.initials: SZ
authors.lastname: Zhong
authors.forename: Jing-fa
authors.initials: JF
authors.lastname: Liu
authors.forename: Da-chuan
authors.initials: DC
authors.lastname: Xu
mesh_terms: D000328:Adult; D002102:Cadaver; D001270:Cervical Atlas / Q000033:anatomy & histology* / Q000601:surgery; D002574:Cervical Vertebrae / Q000033:anatomy & histology* / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D013123:Spinal Fusion / Q000379:methods