Morphological study of the posterior osseous structures of subaxial cervical spine in a population from northeastern China.

Background: Laminar screws and lateral mass screws have been increasingly used in the treatment of cervical diseases. The purpose of this study is to determine the morphological characteristics of the posterior anatomical structures of the subaxial cervical vertebrae in a northeastern Chinese population.

Methods: Sixty-one consecutive patients underwent cervical spine computed tomography (CT). We analyzed a total of 610 axial images and 61 sagittal images. The following parameters were measured: lamina outer width (LOW), lamina inner width (LIW), lamina axis length (LAL), lamina transverse angle (LTA), lateral mass longitudinal diameter (LMLD), lateral mass transverse diameter (LMTD), sagittal spinous process length (SSPL), axial spinous process length (ASPL), spinal canal transverse diameter (SCTD), spinal canal longitudinal diameter (SCLD), osseous spinal canal area (OSCA), and Pavlov ratio (PR). The participants were classified into male and female groups and developmental canal stenosis (DCS; PR ≤0.75) and non-DCS (NDCS; PR >0.75) groups.

Results: Significant differences were observed among the different vertebral levels for almost all evaluated parameters, except for LTA and OSCA. Statistical differences were found between the right and left sides in all parameters, except for LIW and LOW. All linear parameters, except for SCLD and the angular parameter LTA, significantly differed between the sexes. Significant differences were found between the DCS and NDCS groups in terms of all parameters, except for SCTD.

Conclusions: Various measurements of the posterior structures of subaxial cervical vertebrae differed between the left and right sides, females and males, and the DCS and NDCS groups. Different techniques for lateral mass screw insertion should be used according to different vertebral level. Only C7 laminar may be able to safely accommodate a 2.5-mm translaminar screw. The study data can help doctors to make better surgical decisions and develop more appropriate implants for northeastern Chinese patients.