Pedicle screw placement with use of a navigated surgical drill at subaxial cervical spine

Abstract Study design Retrospective cohort study. Objective This study was performed to evaluate the accuracy of cervical pedicle screw (CPS) placement with use of a navigated surgical drill (ND) and to compare it with navigated manual probe (MP) at C3–C6. Methods 47 consecutive patients (27 males and 20 females, 67.2 [33–91] years) underwent a posterior cervical fixation using CPSs under an intraoperative 3D - – CT based navigation system (total 207 CPSs). For initial probing, ND with 2.2-mm steel burr was used since Apr. 2017 (Group ND; 33 patients, 152 CPSs). MP was used earlier (Group MP; 14 patients, 55 CPSs). There were no other different procedures between the two groups. The accuracy of CPS placement was graded with postoperative CT and compared between the two groups. Results There were no significant differences in the total perforation rates both in axial and sagittal planes between Groups ND and MP (axial; 7.2% vs. 14.5%, p = 0.25, sagittal; 10.5% vs. 14.5%, p = 0.46). However, the lateral and rostral perforation rates were significantly reduced in Group ND compared to Group MP (lateral: 36.4% vs. 87.5%, p = 0.04; rostral: 6.3% vs. 100%, p = 0.001). Conclusion Although ND did not decrease the total perforation rate significantly, it reduced the incidence of lateral and rostral perforation. ND is likely to make initial probing easier without a forcible manipulation which might cause vertebral rotation.