Morphometric Evaluation of Thoracic Pedicles in the Turkish Population: Comparison Between Radiological and Direct Anatomical Measurements

Abstract

The objective of the study was to perform a comprehensive morphometric analysis of thoracic vertebrae in the Turkish population and to evaluate the agreement between CT-based and direct anatomical (dry vertebra) measurements, with a focus on surgical relevance for transpedicular screw placement. A total of 157 thoracic vertebrae were evaluated. Morphometric parameters including vertebral body width, length, height; pedicle width, length, and height; and pedicle transverse and sagittal angles were measured using both CT imaging and direct caliper-based anatomical assessment. Statistical comparisons were performed using the Mann-Whitney U test and Cohen's d effect size. Correlations between vertebral body and pedicle dimensions were assessed using Spearman's correlation analysis. Significant correlations were found between vertebral body dimensions and pedicle morphology, particularly between vertebral body length and pedicle length (r = 0.812, p < 0.001). Notable differences were observed between CT-based and anatomical measurements, especially in pedicle height, length, and transverse angle (p < 0.001). CT-based values tended to be larger than those obtained from direct anatomical measurements. The effect size for some differences (e.g., pedicle width) was small, suggesting limited clinical impact, while others (e.g., pedicle length and height) showed moderate to large discrepancies. This study highlights important morphometric characteristics of thoracic vertebrae in the Turkish population and reveals measurement discrepancies between CT and anatomical methods. These findings emphasize the importance of population-specific morphometric data and suggest caution when relying solely on CT-based measurements- especially in settings where free-hand surgical techniques are used without navigation assistance.