ABSTRACT

The purpose of this study is to evaluate the anatomical features of C7 vertebra using some specific measurements in order to select the most appropriate screw for implantation of lateral mass and the pedicle.

We retrospectively enrolled 100 consecutive patients who were admitted to our hospital’s emergency Computed Tomography (CT) department suffering from general body trauma in order to evaluate a potential cervical injury with cervical CT. All subjects are Turkish and 18-60 years old. Patients with cervical fractures or malignancies, anatomical variations, cervical deformity, previous cervical surgery were not included in the study. Pedicle width, pedicle screw length and lateral mass screw length were measured in multiplanar reconstructed CT images at workstation. The mean values in Turkish society were determined and these measurements were compared with the previous studies including other societies.

The mean pedicle length, mean pedicle with and mean lateral mass screw length were 29.1 ±1.1, 6.3 ±0.3, 13.5 ±0.6 respectively. Pedicle screw length was higher in men than women and this difference was statistically significant. Additionally, when compared to other studies in the literature, the length of lateral mass screw was higher in Turkish population and this difference was also statistically significant.

C7 vertebra is a transitional vertebra with difficulties in fixation due to its close relation with important anatomical structures. This level is also known as the transition between the lordotic cervical vertebral column which is quite mobile and kyphotic thoracic vertebral column which is fixed biomechanically. When planning the fixation of the cervicothoracic region with instrumentation, it has some difficulties for the spine surgeons due to its anatomical features. Compared to other studies in the literature with Magerl technique usage in measurements, the lateral mass screw length in Turkish society is statistically different than other races. Our study is the first study about the anatomy of C7 vertebra in Turkish society.