CT evaluation of cervical pedicle in a Chinese population for surgical application of transpedicular screw placement

Abstract

The lower cervical pedicle size differs between the Chinese and the non-Chinese population. Knowledge of pedicle dimensions and surface landmarks is crucial for the safe placement of screws, but few quantitative data concerning the lower cervical pedicle using CT scan and multiplanar reformations (MPR) in a Chinese population exist. The aim of this study was to evaluate lower cervical pedicle (C3-C7) dimensions in a Chinese population by computed axial tomography for surgical application. The dimensions of the pedicles (C3-C7) were determined in 60 patients from CT images of cervical spinal lesions. Measurements of pedicle height, width, pedicle axis length, effective length, and two angles of the pedicles, the distances from the projection point of the pedicle axis to the lateral edge of the lateral mass and to the inferior edge of the superior facet were measured. The smallest outer pedicle width was found at C3 among the female and C4 among the male. This measurement was significantly different between male and female patients in the outer pedicle width (P < 0.05; independent samples t test) at C3 and C4. The mean values of the outer pedicle width ranged from 5.4 to 6.7 mm in males, and 4.4 to 6.3 mm in females. The projection point of the pedicle axis in the lateral-superior area of the cervical lateral mass was the most important. There were significant correlations (P < 0.01; Kendall's W test) between the vertebral level and both pedicle angles (PTA and PSA). The smallest pedicle transverse angle was at C7 in males and females. The cervical spinal cord or vertebral artery may be at risk of injury if the angulation of the screw insert is over-medial or over-lateral in the transverse plane. Therefore, preoperative CT evaluation of pedicle transverse angle is very important. Considering the amount of variation among individuals, our data on CT measurements of pedicle in a Chinese population in conjunction with evaluation of the results of preoperative CT may enhance the safety of transpedicular screw fixation in the lower cervical spine.

Cervical pedicle morphometry in a Latin American population

“…Despite the cervical pedicle surgical anatomy was well documented in North America, Asia, and Europe, [9,13,14] the anatomical parameters of the cervical spine pedicles may vary among different regions, and there are limited studies about a Latin American population, detailing bony landmarks and parameters to establish the ideal trajectory and feasibility of the cervical transpedicular screw technique. Our hypothesis was that morphometric parameters of the cervical pedicle of a Brazilian population would differ from previously reported data.…”

Anterior transpedicular screw fixation of cervical spine: Is it safe? Morphological feasibility, technical properties, and accuracy of manual insertion

“…6,14,35 In our study, the mean PW and PH values were greater in males than in females and constantly increased from the cephalad to the caudad, as reported in the literature. 11,30,31 There were no significant differences between the right and left pedicles. The overall mean PH values were 1-2 mm greater than the PW values at all levels, as reported by Panjabi et al 28 and Kareikovic et al 14 The overall mean PH ranged from 6.2 to 7.5 mm in their studies, resembling the observations of Onibokun et al 27 None of the PH measurements was below 4 mm.…”

Subaxial Cervical Pedicle Morphometric Assessment in Normal South Indian Subjects using Computed Tomography Scan Images

“…3 Various biomechanical studies have shown that cervical pedicle screw has a better pullout strength than other posterior cervical fixation techniques and failure rate is significantly low. [4][5][6][7] The cervical pedicle surgical anatomy has been studied in North America, Asia, and Europe, [8][9][10][11][12] and it has anatomical parameters of the cervical spine pedicles that may differ in various regions. Indian population have been studied for cervical pedicle morphometry 13,14 but there are no studies about South Indian population without any cervical spine pathology.…”

“…2,8 The transverse pedicle diameter increases from C3 to C7 in both male and female subjects. 9 We observed that mean transverse PW from C3 to C5 was found to be 5.4 mm in males and 4.6 mm in females, C6 to C7 was found to be 5.6 mm in males and 5.3 mm in females, so we recommend 5 mm pedicle screws in C3 to C5 for males and 4 mm pedicle screws for females, and 5.5 mm pedicle screws in males and 5 mm pedicle screws for females in C6, C7 region to avoid vascular and neural injuries (Graph 5, Table 5).…”