Keywords: پیچ پیوندی; Atlantoaxial fixation; Biomechanics; Vertebral artery injury prevention; C1LH; C1 laminar hook; C1LMS; C1 lateral mass screw; C2ILS; C2 intralaminar screw; C2PS; C2 pedicle screw; CT; Computed tomography; ROM; Range of motion; TAS; Transarticular screw; V