CT analysis of C2 pedicles morphology and considerations of useful parameters for screwing

Abstract

These morphological data come from a large series give some help for the C2 pedicle screwing preoperative planning. These lean on 3D measures but also on accessible mark during the procedure and despite the difference of the patient orientation. A CT preoperative planning of the pedicle screwing remains essential because more than 7 % of the pedicles have a diameter lower than 4 mm.

CT Evaluations for C2 Pedicle Screw Fixation: Multiplanar Computerized Tomography Measurements in 100 Moroccan Patients

“…Outer pedicle width dimensions of C2 in this study (average, range of 5.2 ± 0.5 mm) were similar in both as in females to those in Asian [13] and European [17] studies who reported an average range of 5.2 to 5.4 mm and 5.18 ± 1.25 mm respectively. It showed also that PTW was smaller-sized compared to the result of Jay U et al [16], Tomasino et al [18] and Sakamoto et al [19] with an average range of range 6.4-9 mm, 5.6 ± 1.2 mm and 5.5 -7.7 mm respectively.…”

Clenching Reduction Technique for Osteosynthesis of Atypical C2 Fractures with the Combining Use of Laminar and Pedicle Screw: A Technical Note

“…Analysis of the C2 lamina found there was enough space (width and length) to insert a laminar screw. 7,8 We report the reduction of a displaced hangman's fracture by compression across crossed laminar screws. In addition, we were able to reduce the fracture gap by using the clenching reduction technique with a unilateral pedicle screw and an opposite-site laminar screw.…”

"Two-step" technique with OsiriXTM to evaluate feasibility of C2 pedicle for surgical fixation

“…We use this function of OsiriX™ (version 5.5.2, Pixmeo, Geneva, Switzerland) to determine the anatomical variations (i.e., C2 pedicle/VA route) of this region in only two simple steps and additionally to calculate the position, length and angle of screws, as others have described. [ 4 ]…”

“…[ 2 3 ] However, quite often, it is difficult, and sometimes misleading, to evaluate anatomical bony variations (i.e., C2 pars or pedicle morphology) and vascular anomalies [i.e., high riding vertebral artery (VA)] using only the conventional three orthogonal planes of CT (axial, coronal, and sagittal). [ 4 ] For example, in Figure 1 (a type II odontoid fracture in a 92-year-old patient [case 2]), only by changing the gantry angle of the axial plane (from the plane of the inter-vertebral disc to the possible pedicle angle) is enough to clarify the position of VA. Additionally, frequently the “true” plane is biased either because of suboptimal acquisition technique, or because of patient-related factors, such as scoliosis, rotation, or dislocation of vertebral bodies.…”