Morphometric analysis of typical cervical vertebral pedicle - An osteological study

Abstract

Background: Successful placement of cervical pedicle screws requires accurate identification of entry point, trajectory and appropriate size of implant. Studies and guidelines regarding the direction of pedicle screw insertion and pedicle dimensions in Indian population are very limited and hence the objective of our study was to do Morphometric analysis of Typical Cervical Vertebral pedicle (C3 to C6) Materials and Methods: Osteological study of the pedicle was performed in 100 typical (C3-C6) dry bone specimens. The vertebral pedicles were evaluated by measuring its height, width, length, lateral mass + pedicle length, total pedicle axis length and transverse pedicle angle. Results: In our study, the mean pedicle length of C3, C4, C5, C6 was 6.04, 5.48, 5.30, and 5.92 respectively. The mean pedicle height in our study ranged from 5.05 mm (C3) to 5.86 mm (C6). The Range of Mean pedicle width was from 4.79 to 5.16 mm. The mean lateral mass + pedilce length ranged from 11.17 to 13.18 mm while the mean total pedicle axis length ranged from 27.05 to 30.04 mm. Conclusions: We found that there were high individual variations. The pedicle dimensions were relatively smaller in Indians compared to previous studies in other population. This mandates preoperative CT evaluation of pedicle and smaller size pedicle screws customized according to pedicle dimensions of Indians.