Three dimensional morphometric analysis of cervical uncinate process from C3 to C7 with surgical implications

Abstract

The uncinate process is a key anatomical structure in the cervical spine, essential for uncovertebral joint formation and spinal biomechanics. Although its linear dimensions have been previously described, the relationship between its vertical height and angular orientation remains underexplored. This study aimed to evaluate the three-dimensional morphometry of the uncinate process from C3 to C7, focusing on correlations between height and angular parameters. Fifty-one dry human cervical vertebrae (C3-C7), obtained from multiple adult donors (donor count unknown; sex unknown), were analyzed using high-resolution CT (0.75-mm slices). Although specimens were unevenly distributed across vertebral levels, measurements included uncinate height, uncinate angle, and endplate angle on coronal reconstructions. Statistical analysis involved Wilcoxon signed-rank, Kruskal-Wallis, and Spearman's correlation tests. No significant side-to-side differences were found in uncinate height or angle, though the endplate angle was significantly higher on the left. Inter-level comparisons revealed significant differences in left uncinate height and bilateral endplate angles. Importantly, uncinate height showed a strong negative correlation with uncinate angle (Right: rho = - 0.557; Left: rho = - 0.677; both p < 0.001) and a strong positive correlation with endplate angle (Right: rho = 0.777; Left: rho = 0.809; both p < 0.001). These findings underscore the anatomical variability and interdependence of vertical and angular features of the uncinate process, with implications for uncovertebral joint mechanics and surgical approach planning. Recognizing such variations may improve safety and accuracy in anterior cervical spine procedures.