Morphometric Study of C1 Pedicle and Feasibility Evaluation of C1 Pedicle Screw Placement with a Novel Clinically Relevant Radiological Classification in an Indian Population

Abstract

Study DesignA retrospective computed tomography (CT)-based morphometric study of 84 C1pedicles in an Indian population focusing on critical morphometric dimensions vis-a-vis C1 pedicle screw placement.PurposeTo determine the feasibility of C1 pedicle screw placement in an Indian population and propose a novel classification system for the same.Overview of LiteratureAt present, C1 pedicle screws are rarely used, and very few studies have focused on the feasibility of pedicle screw placement in terms of racial, gender, and ethnic variations in anatomical structures. There are no CT-based data on C1 pedicles that assess the feasibility of pedicle screw placement in the Indian population.MethodsWe measured C1 pedicle diameter on CT coronal scan images of 42 adult patients. Extramedullary height (EMH) and intramedullary height (IMH) were measured. We examined the differences between the right and left atlas pedicles and compared measures between males and females. These data were analyzed using significance tests. Based on the results, we propose a novel classification system, which we believe will help in determining the feasibility of C1 pedicle screw placement.ResultsForty-two adult patients (84 pedicles) were examined. Average EMH and IMH were 4.48±0.91 and 0.86±0.77, respectively. Approximately, 32% of the C1 pedicles had bone thicknesses of <4 mm, 49% had IMH of <1 mm, and 38% had no pedicles. The average thickness in women was 4.21±0.93 mm, which was significantly thinner than that in men (4.73±0.81 mm, p=0.004). Right and left pedicles were not significantly different.ConclusionsOur data indicate that approximately one-third of the Indian population may not be suitable candidates for C1 pedicle screw placement. Caution should be exercised while placing type 1B and type 2 pedicles based on our proposed classification system.

Morphometric Study for C1 Pedicle Screw Placement in Thai Patients

“…The current study found C1 pedicle height was 4.77 mm, which was consistent with a study by Christensen et al 15 who reported a C1 pedicle height of 4.80 mm in Western Blacks and White Caucasians. The mean height of the C1 pedicle of the current study was greater than the mean heights of the Tan et al 12 study (4.58 mm), Srivastava et al 16 study (4.48 mm), and the Qian et al 17 study (4.43 mm). This likely occurred due to ethnic differences.…”

The morphological classification and clinical significance of atlas vertebral artery sulcus based on computed tomography three-dimensional reconstruction

“…A The line ab was measured as the C1 pedicle length, and the line cd was measured as the pedicle width affect the placement of pedicle screws [15][16][17]. Some scholars described the morphology of the atlas vertebral artery sulcus, but neither of them classified the vertebral artery sulci and investigated the effect of different types on pedicle screw placement [11,[18][19][20]. Therefore, these previous studies were different from the current study.…”

The morphological classification and clinical significance of atlas vertebral artery sulcus based on Computed Tomography three-dimensional reconstruction

“…The diameter and variation of vertebral artery groove directly affect the placement of pedicle screws [16][17][18]. Some scholars [12,19,20,21]described the morphology of atlas vertebral artery groove, but the classi cation was different. There were also studies to guide the placement of pedicle screws according to the height of atlas pedicle [22][23][24][25]; but few reports on pedicle screw placement guided by vertebral artery groove classi cation.…”