Aim: To conduct a detailed computed tomography (CT) assessment of dimensions of the subaxial cervical spine pedicle in volunteers without any cervical spine pathology.
Materials and methods:Sixty-six asymptomatic subjects were analyzed in a single center using cervical spine CT, with imaging reconstruction of each vertebra in axial plane with 1 mm, and in sagittal plane reconstruction with 2 mm slice thickness. Height and weight of each volunteer were measured and body mass index (BMI) was calculated. Parameters, such as pedicle width (PW), pedicle axis length (PAL), pedicle transverse angle (PTA) in axial plane, and pedicle height (PH) in sagittal plane were measured and analyzed. Height and weight of each subject were measured and BMI was calculated as per the formula.
Results:The analysis of CT scan images of the cervical spine of 66 asymptomatic subjects with mean age of 45 years with equal distribution of males and females gave mean BMI values as males: 24.58 ± 2.6 and females: 24.03 ± 2.07. Mean values of PAL were smaller in females compared with males, PAL progressively increased from C3 to C6 vertebrae level for both males and females, while C6 and C7 were similar. The PTA showed no gender variation. However, PTA among C3 to C7 demonstrated the same pattern among the left and right pedicles as they had wide angle in the upper subaxial cervical spine, C3 to C6, and became slightly narrow in the lower cervical region at C7. The PH was found to be smaller in females in comparison with males. The PH difference was observed between left and right-side values for men and women, men's right-side values were higher, whereas higher left-side values were observed in females. The PW was found to be smaller in females in comparison with males, PW increased from C3 to C7 vertebrae level, but we found little difference between left side and right side for both men and women.
Conclusion:Our results are in correlation with previous studies, but our study showed strong correlation between BMI and PW, and the frequency of subjects with PW < 3.5 mm in our population especially in females is higher, suggesting an increased risk to the neurovascular structures while attempting transpedicular screw technique, especially in females.