Morphometric Analysis of the Uncinate Process–Transverse Foramen Corridor in Older Korean Adults: A Comparison with Younger Adults

Objective: This study aimed to compare the morphometric characteristics of the osseous corridor between the uncinate process (UP) and transverse foramen (TF) in older and younger adults and to explore sex differences within the older cohort.Methods: We retrospectively analyzed cervical computed tomography angiography images from 130 participants: 30 younger adults aged 18-30 years and 100 older adults aged 65-89 years.UP and TF morphometric parameters were measured bilaterally at C3-C6.In an exploratory subgroup analysis, older men and women were compared using skeletal-size-adjusted indices normalized to the interuncinate base width.Linear mixed-effects models evaluated group and cervical-level effects and their interactions; Bonferroni-adjusted pairwise comparisons assessed differences at each level.The older cohort was also assessed for anomalous foraminal anatomy related to the vertebral artery (VA) using a predefined osseous criterion.Results: At C4-C6, the older cohort had significantly shorter UP tip-to-TF medial wall distances and greater interuncinate tip distances than the younger cohort.Group-by-level interactions were significant for UP tip-to-TF medial wall, interforaminal, and interuncinate tip distances.In the exploratory sex-based analysis, only the skeletal-size-adjusted TF diameter showed a significant sex-by-level interaction; the other sex differences were confined to selected pairwise comparisons at individual levels.One older participant (1.0%) met the predefined VA-related osseous criterion.Conclusion: The UP-TF corridor was narrower at selected lower cervical levels in older adults than in younger adults, whereas skeletal-size-adjusted sex differences were limited.These findings may inform individualized preoperative assessment and surgical planning.