title: CT morphometric analysis to determine the anatomical basis for the use of transpedicular screws during reconstruction and fixations of anterior cervical vertebrae.
abstract: BACKGROUND
  Accurate placement of pedicle screw during Anterior Transpedicular Screw fixation (ATPS) in cervical spine depends on accurate anatomical knowledge of the vertebrae. However, little is known of the morphometric characteristics of cervical vertebrae in Chinese population.
  
  
  METHODS
  Three-dimensional reconstructions of CT images were performed for 80 cases. The anatomic data and screw fixation parameters for ATPS fixation were measured using the Mimics software.
  
  
  RESULTS
  The overall mean OPW, OPH and PAL ranged from 5.81 to 7.49 mm, 7.77 to 8.69 mm, and 33.40 to 31.13 mm separately, and SPA was 93.54 to 109.36 degrees from C3 to C6, 104.99 degrees at C7, whereas, 49.00 to 32.26 degrees from C4 to C7, 46.79 degrees at C3 (TPA). Dl/rSIP had an increasing trend away from upper endplate with mean value from 1.87 to 5.83 mm. Dl/rTIP was located at the lateral portion of the anterior cortex of vertebrae for C3 to C5 and ipsilateral for C6 to C7 with mean value from -2.70 to -3.00 mm, and 0.17 to 3.18 mm. The entrance points for pedicular screw insertion for C3 to C5 and C6 to C7 were recommended -2∼-3 mm and 0-4 mm from the median sagittal plane, respectively, 1-4 mm and 5-6 mm from the upper endplate, with TPA being 46.79-49.00 degrees and 40.89-32.26 degrees, respectively, and SPA being 93.54-106.69 degrees and 109.36-104.99 degrees, respectively. The pedicle screw insertion diameter was recommended 3.5 mm (C3 and C4), 4.0 mm (C5 to C7), and the pedicle axial length was 21-24 mm for C3 to C7 for both genders. However, the ATPS insertion in C3 should be individualized given its relatively small anatomical dimensions.
  
  
  CONCLUSIONS
  The data provided a morphometric basis for the ATPS fixation technique in lower cervical fixation. It will help in preoperative planning and execution of this surgery.
authors.affiliation: Department of Anatomy, Southern Medical University and Guangdong Provincial Medical Biomechanical Key Laboratory and Academy of Orthopedics of Guangdong Province, Guangzhou, Guangdong, China ; Department of Orthopedic Surgery, The Navy General Hospital, Southern Medical University, Beijing, China ; The Third School of Clinical Medicine, Southern Medical University, Guangzhou, Guangdong, China.
authors.forename: Chun
authors.initials: C
authors.lastname: Chen
authors.affiliation: Department of Orthopedic Surgery, The Navy General Hospital, Southern Medical University, Beijing, China.
authors.forename: Dike
authors.initials: D
authors.lastname: Ruan
authors.affiliation: Department of Anatomy, Southern Medical University and Guangdong Provincial Medical Biomechanical Key Laboratory and Academy of Orthopedics of Guangdong Province, Guangzhou, Guangdong, China.
authors.forename: Changfu
authors.initials: C
authors.lastname: Wu
authors.affiliation: Department of Anatomy, Southern Medical University and Guangdong Provincial Medical Biomechanical Key Laboratory and Academy of Orthopedics of Guangdong Province, Guangzhou, Guangdong, China.
authors.forename: Weidong
authors.initials: W
authors.lastname: Wu
authors.affiliation: Department of Anatomy, Southern Medical University and Guangdong Provincial Medical Biomechanical Key Laboratory and Academy of Orthopedics of Guangdong Province, Guangzhou, Guangdong, China.
authors.forename: Peidong
authors.initials: P
authors.lastname: Sun
authors.affiliation: Department of Orthopedic Surgery, Affiliated Hospital of Inner Mongolia Medical College, Inner Mongolia, China.
authors.forename: Yuanzhi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Orthopedic Surgery, The 306th Hospital of People's Liberation Army, Beijing, China.
authors.forename: Jigong
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Orthopedic Surgery, Kunming General Hospital, Kunming, Yunnan, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Lu
authors.affiliation: Department of Anatomy, Southern Medical University and Guangdong Provincial Medical Biomechanical Key Laboratory and Academy of Orthopedics of Guangdong Province, Guangzhou, Guangdong, China ; Shenzhen Digital Orthopedic Engineering Laboratory, Shenzhen, Guangdong, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Ouyang
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012984:Software; D014057:Tomography, X-Ray Computed / Q000379:methods*