Liujun Zhao1, Jinjiong Hong2, Meghan E Wandtke3, Rongming Xu2, Weihu Ma2, Weiyu Jiang2, Yongjie Gu2, Jianqing Chen2, Liran Wang2, Jiayong Liu3, Nabil A Ebraheim3. 1. Department of Orthopaedic Surgery, Ningbo 6th Hospital, Ningbo University, 1059#, Zhongshan Dong Road, Ningbo, Zhejiang, People's Republic of China. zhaoliujun555@sina.com.cn. 2. Department of Orthopaedic Surgery, Ningbo 6th Hospital, Ningbo University, 1059#, Zhongshan Dong Road, Ningbo, Zhejiang, People's Republic of China. 3. Department of Orthopaedic Surgery, University of Toledo Medical Center, Toledo, OH, 43614, USA.
Abstract
STUDY DESIGN: We evaluated the trajectory and the entry points of anterior transpedicular screws (ATPS) in the cervicothoracic junction (CTJ). OBJECTIVE: This study aimed at investigating the feasibility of ATPS fixation in the CTJ. Application of an ATPS in the lower cervical spine has been reported; however, there were no reports exploring the feasibility of anterior transpedicular screw fixation in the CTJ. METHODS: CT scans were performed in 50 cases and multiplanar reformation was used to measure the related parameters on pedicle axis view at C6-T2. Transverse pedicle angle, outer pedicle width, pedicle axis length, distance transverse intersection point (DtIP), sagittal pedicle angle, anterior vertebral body height, outer pedicle height, and distance sagittal intersection point (DsIP) were measured. The prozone of CTJ was divided into three different regions, which were named as the "manubrium region", the region "above" and "below" the manubrium. The distribution of the trajectory of sagittal pedicle axes was recorded in the three regions and the related data were statistically analyzed. RESULTS: There was no statistical difference in gender (P > 0.05). The transverse pedicle angle decreased from C6 (46.77° ± 2.72°) to T2 (20.62° ± 5.04°). DtIP increased from C6 to T2. DsIP was an average of 7.17 mm. The sagittal pedicle axis lines of the C6 and C7 were located in the region above the manubrium. T1 was mainly in the manubrium region followed by the region above the manubrium. T2 was mainly located in the manubrium region followed by the region below the manubrium. CONCLUSION: Implantation of ATPS at C6, C7, and some T1 is feasible through the low anterior cervical approach, while it is almost impossible to approach T2 that way.
RCT Entities:
STUDY DESIGN: We evaluated the trajectory and the entry points of anterior transpedicular screws (ATPS) in the cervicothoracic junction (CTJ). OBJECTIVE: This study aimed at investigating the feasibility of ATPS fixation in the CTJ. Application of an ATPS in the lower cervical spine has been reported; however, there were no reports exploring the feasibility of anterior transpedicular screw fixation in the CTJ. METHODS: CT scans were performed in 50 cases and multiplanar reformation was used to measure the related parameters on pedicle axis view at C6-T2. Transverse pedicle angle, outer pedicle width, pedicle axis length, distance transverse intersection point (DtIP), sagittal pedicle angle, anterior vertebral body height, outer pedicle height, and distance sagittal intersection point (DsIP) were measured. The prozone of CTJ was divided into three different regions, which were named as the "manubrium region", the region "above" and "below" the manubrium. The distribution of the trajectory of sagittal pedicle axes was recorded in the three regions and the related data were statistically analyzed. RESULTS: There was no statistical difference in gender (P > 0.05). The transverse pedicle angle decreased from C6 (46.77° ± 2.72°) to T2 (20.62° ± 5.04°). DtIP increased from C6 to T2. DsIP was an average of 7.17 mm. The sagittal pedicle axis lines of the C6 and C7 were located in the region above the manubrium. T1 was mainly in the manubrium region followed by the region above the manubrium. T2 was mainly located in the manubrium region followed by the region below the manubrium. CONCLUSION: Implantation of ATPS at C6, C7, and some T1 is feasible through the low anterior cervical approach, while it is almost impossible to approach T2 that way.