Mid-Term Results of Computer-Assisted Cervical Pedicle Screw Fixation

Study Design: A retrospective study. Purpose: The present study aimed to evaluate mid-term results of cervical pedicle screw (CPS) fixation for cervical instability. Overview of Literature: CPS fixation has widely used in the treatment of cervical spinal instability from various causes; however, there are few reports on mid-term surgical results of CPS fixation. Methods: Record of 19 patients who underwent cervical and/or upper thoracic (C2-T1) pedicle screw fixation for cervical instability was reviewed. The mean observation period was 90.2 months. Evaluated items included Japanese Orthopaedic Association (JOA) score and C2-7 lordotic angle before surgery and at 5 years after surgery. Postoperative computerized tomography was used to determine the accuracy of screw placement. Visual analog scale (VAS) for neck pain and radiological evidence of adjacent segment degeneration (ASD) at the 5-year follow-up were also evaluated. Results: Mean JOA score was significantly improved from 9.0 points before surgery to 12.8 at 5 years after surgery (p=0.001). The C2-7 lordotic angle of the neutral position improved from 6.4 degrees to 7.8 degrees at 5 years after surgery, but this was not significant. The major perforation rate was 5.0%. There were no clinically significant complications such as vertebral artery injury, spinal cord injury, or nerve root injury caused by any screw perforation. Mean VAS for neck pain was 49.4 at 5 years after surgery. The rate of ASD was 21.1%. Conclusions: Our mid-term results showed that CPS fixation was useful for treating cervical instability. Severe complications were prevented with the assistance of a computed tomography-based navigation system.