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Updated: Jun 13, 2025
An Anesthesia, Surgery, and Harvest Method for the Evaluation of Transpedicular Screws Using an In Vivo Porcine Lumbar Spine Model
Published on: May 31, 2017
CT correlation of spinal canal diameter with pedicle size for safer posterior cervical pedicle screw fixation
Yushi Nagano1, Hitoshi Yamahata1, Ryutaro Makino1
1Department of Neurosurgery, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan.
Background:
Utilizing computed tomography (CT) studies, we correlated cervical spinal canal diameters (SCDs) with pedicle size between the C3 and C7 levels to more safely perform posterior cervical surgery.
Methods:
We retrospectively analyzed CT studies for 71 patients with cranial or spinal disorders and correlated the cervical SCD with the pedicle outer width (POW) between the C3 and C7 levels. Patients were divided into normal (SCD ≥12 mm at any level, n = 30) and stenosis groups (SCD <12 mm at any level, n = 41).
Results:
C7 exhibited the largest SCD and POW values, while C3 and C4 exhibited the smallest SCD and POW values. Moderate correlations (r = 0.3, P = 0.002) were observed at the C3 and C4 levels but no significant correlations were observed from the C5 to C7 levels. For SCD values, the normal group demonstrated significantly greater values between the C3 and C7 levels versus the stenosis group. For POW values, only the C4 level differed significantly between the two groups (P = 0.014, Mann-Whitney U-test).
Conclusion:
Preoperative pedicle size evaluation remains an essential manoeuvre before performing cervical C3-C7 pedicle screw placement. In 71 cervical CT studies, we found no consistent correlation between POW and SCD values, indicating that it is difficult to estimate POW values based on spinal canal size.
