Radiological morphometric analysis of cervicothoracic junction vertebrae pedicles

To provide detailed morphometric reference data and evaluate demographic correlations of the cervicothoracic junction (CTJ) to support individualized and safer transpedicular fixation.

One hundred consecutive patients (50 males, 50 females; age range 19-83, mean 54.2) who underwent contrast-enhanced cervicothoracic CT from May 2020 to May 2022 were retrospectively analyzed. A total of 1,000 pedicles (C7-T4) were measured for pedicle width (PW), pedicle height (PH), pedicle length (PL), pedicle axial angle (PAA), pedicle sagittal angle (PSA), and central canal diameter (CCD). Intra- and interobserver repeatability was estimated using the intraclass correlation coefficient. Vertebral artery (VA) entry level and transverse foramen hypoplasia were recorded. Relationships with age, height and body mass index (BMI) were assessed.

Males had significantly larger PW, PH and PL across all levels. PW peaked at T1 and narrowed toward T4; PH increased from C7 to a maximum at T3. PAA decreased caudally from C7 to T4, while PSA increased caudally. Significant left-right asymmetries were found. Age correlated positively with PW (except T4), PH (except C7) and PL, which were stronger in females, while height correlated positively with PW, PH, PL and CCD. BMI showed limited associations. VA entered the transverse foramen at C6 in the vast majority of cases and C7 transverse foramen hypoplasia was bilateral in 17%.

These level, side and sex specific CTJ reference data, together with demographic correlations, provide practical guidance for individualized screw diameter, length and trajectory selection to reduce operative risk.