Журнал позвоночника

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

Abstract

Said Hilmani, Rim Amzil and Abdessamad El-Azhari

Background: Transpedicular screw fixation in the Axis is difficult due to its relation with adjacent anatomic features. Successful placement requires a sufficient understanding of axis pedicle.

Objective: The aim was to assess length and width of the C2 pedicle in Moroccan population in order to evaluate the safety of pedicle screw fixation.

Patients and methods: We evaluated the C2 pedicle morphology using computed tomography (CT) imaging in 100 patients (30 females and 70 males; age range, 18–70; mean, 36,2 ± 11,9 years). Axial CT cutting was made at 1.25 mm intervals. The measurements of C2 pedicles were performed on CT images using its measurement tools. The pedicle transverse width was defined as the mediolateral diameter of the pedicle isthmus. Pedicle length (distance from the posterior cortex of the lateral mass to the middle of the vertebral body).

Results: The overall mean pedicle transverse widths (PTW) were 5.3 mm (4.1 to 7.1 mm), in males were 5.2 ± 0.5 mm and 5 ± 0.4 mm in females. The overall mean pedicle lengths (PL) were ranged from 19,7 to 26.7 mm with average 22.5 mm. The mean PL in female was 21.8 ± 1.4 mm and 22.8 ± 1.7 mm in male. The mean PTW and PL were greater in males than in females at both sides, and this difference was statistically significant. On the other hand, they were not correlated to age in our adult patients.

Conclusion: Our findings suggest that there were significant differences between individuals and ethnics. The preoperative CT scans undergoing cervical transpedicular fixation should be thoroughly analyzed for successful pedicle screws placement.