Computerized Tomography-Based Morphometric Analysis of Subaxial Cervical Spine Pedicle in Asymptomatic Indian...

The purpose of this study was to analyze morphometry of the subaxial cervical spine pedicles in an Indian population based on computed tomography (CT), and thus assess the safety and feasibility of cervical pedicle screw in the subaxial cervical spine.

CT scans of 500 subaxial cervical spine vertebrae were analyzed from 100 patients presenting to our institution and undergoing cervical spine CT scan for an unrelated cause as part of ATLS protocol. Pedicle width (PW), pedicle axis length (PAL), pedicle transverse angulation (PTA), and lateral pedicle distance (LPD) were calculated on axial CT scans, and pedicle height (PH), pedicle length (PL), superior pedicle distance (SPD), and pedicle sagittal angulation (PSA) were calculated on sagittal CT scans.

The mean PW ranged from 4.3 mm at C3 to 5.7 mm at C7. Mean PH ranged from 5.5 mm at C3 to 6.1 mm at C7. Mean PTA ranged from 44.5° at C3 to 37.1° at C7. PSA ranged from 16.65° at C3 to 3.29° at C7. Mean LPD ranged from 1.6 mm at C3 to 3.4 mm at C6. Mean SPD ranged from 3.5 mm at C3 to 1.15 mm at C7. Mean PAL ranged from 29.6 mm at C3 to 33.04 mm at C7. Mean PL ranged from 5.2 mm at C3 to 5.78 mm at C7.

Our CT-based morphometric study confirms that cervical pedicle screw placement is possible in most of the Indian population except at C3 in females. A thorough understanding of pedicle anatomy with proper CT-based preoperative planning can mitigate the risk associated with pedicle screw placement in subaxial cervical spine.