O-Arm Navigated Cervical Pedicle Screw Fixation in the Treatment of Lower Cervical Fracture-Dislocation

To evaluate the safety and efficacy of cervical pedicle screw (CPS) placement with O-arm navigation in the treatment of lower cervical fracture-dislocation.

A retrospective clinical study was performed involving 42 consecutive patients with lower cervical spine fracture-dislocation who underwent CPS fixation surgery with O-arm navigation (CPS group) or received conventional lateral mass screw (LMS) fixation surgery (LMS group) between August 2015 and August 2019. Accuracy of CPS position was evaluated by postoperative CT. The clinical parameters including preoperative and final follow-up Japanese Orthopaedic Association (JOA) score and American Spinal Injury Association (ASIA) Impairment Scale, preoperative Sub-axial Injury Classification (SLIC) score, number of fixation segments, operation time, intraoperative blood loss, injury mechanism, injury location, surgical complications were also assessed between the two groups.

In LMS group, the preoperative SLIC score was 7.5 ± 0.9, ASIA score improvement was 0.8 ± 0.5, JOA score improvement was 3.0 ± 1.8, mean operation time was 204 ± 89 min, intraoperative blood loss was 311 ± 127 ml. In CPS group, the preoperative SLIC score was 7.3 ± 1.2, ASIA score improvement was 0.9 ± 0.5, JOA score improvement was 3.2 ± 2.4, mean operation time is 241 ± 85 min, intraoperative blood loss is about 327 ± 120 ml. There was no significant difference in terms of above clinical parameters between the two groups (P > 0.05), the fixation segments in CPS group (3.5 ± 1.1) were less than that in LMS group (4.2 ± 0.7) (P = 0.037). The accuracy of CPS insertion was evaluated based on postoperative CT. Of all the 118 CPSs, 83 (70.3%) were defined as Grade 0; 27 (22.9%) as Grade 1; eight (6.8%) as Grade 2; and none as Grade 3. CPS malposition rate in this study was 6.8%. In this study, there was no direct intraoperative or postoperative complication caused by CPS or LMS insertion. All the operations were successfully completed in two groups. One of the patients in LMS group presented cerebrospinal fluid leak caused by bone fragment broken of the dural sac, which led to delayed incision healing. CPS group and LMS group both had two patients who suffered pulmonary infection after surgery. A total of 78.6% of the patients showed evidence of neurologic recovery. Satisfactory reduction was achieved in all cases and maintained throughout the follow-up duration.

In the treatment of lower cervical spine fracture-dislocation, cervical pedicle screw insertion with O-arm navigation is a safe and effective method for posterior fixation.