Abstract / Summary
Although cervical pedicle screws (CPS) improve outcomes in trauma and deformity surgery, existing morphometric studies have not been systematically consolidated. This systematic review aims to pool available data to characterize subaxial cervical pedicle dimensions and insertion angles across geographically diverse populations and evaluate population-level anatomical variation relevant to cervical pedicle screw planning.
PubMed, Embase, and Google Scholar were searched to identify anatomical studies published between database inception and August 1, 2024 that reported computed tomography (CT) measurements obtained from at least 10 patients who underwent CPS placement or from at least 10 cadaveric specimens. Five measurements in these studies were analyzed: pedicle width (PW), pedicle height, mean screw length, pedicle transverse angle (PTA), and the difference between the widest and narrowest PTA along the subaxial cervical spine. Pooled means were analyzed for all subaxial vertebrae from patients in the different geographic regions identified during our literature search.
Forty-eight articles comprising 4014 patients from 18 countries in East Asia, Southern Asia, Southeast Asia, the Middle East, the USA, Europe, and East Africa were included. Statistically significant differences in PW were observed across geographic groups at the C3, C5, C6, and C7 vertebral levels, with the largest mean pedicle dimensions found in East Asian populations and the smallest in South Asian populations. Additionally, PW was consistently greater in men than women at all levels. PTA was significantly different between subgroups at C7, where the sharpest PTA was recorded in the East Asia subgroup (p < 0.05).
This study identified population-level differences in cervical pedicle morphology across geographic regions that may inform individualized preoperative planning. Future studies correlating morphometric variation with surgical outcomes are needed.