Occipitocervical Fusion via Cervical Pedicle Fixation Assisted with O-arm Navigation

Objective To describe the clinical outcomes of occipitocervical fusion (OCF) using cervical pedicle fixation with assistance of O-arm navigation and present its clinical feasibility. Methods From January 2015 to December 2016, eight patients with a variety of diagnoses were surgically treated with occipitocervical fusion using cervical pedicle screws under O-arm navigation. All patients received full workup consisting of clinical and radiological assessments. Perioperative parameters including operating time, intraoperative blood loss, postoperative complications, surgical outcomes were recorded. Postoperative data were acquired resorting to the scheduled follow-up 3, 6 and 12 months after their discharge and annually afterwards. The Japanese Orthopaedic Association (JOA) Scores and American Spinal Injury Association (ASIA) Scale were used to evaluate neurological function. The accuracy of screw placement was classified according to a modified classification of Gertzbein and Robbins. The fusion status was evaluated in reference to the Bridwell's posterior fusion grades. Results The patient cohort comprised of five males and three females, with the average age of 51.9 years (range from 18 to 74 years). The patients all showed indications for OCF and were performed with polyaxial screws through cervical pedicles. The average operation time was 274 min (range from 226 to 380 min), with the intraoperative blood loss of 437.5 mL and the blood transfusion volume of 481.3 mL. The average follow-up time was 23.5 months (range from 17 to 32 months). All patients exhibited radiographic evidence of osseous fusion by X-ray and computed tomography (CT) at the final follow-up. No neurovascular complications were found during the follow-up time, and the clinical symptoms were observed to be significantly improved in all the patients. Thirty-four cervical pedicle screws were implanted within the eight patients, with the accuracy of cervical pedicle screw placements as 94.1% (32/34), among which, two pedicle screws were found to broken through the cervical pedicles that were evaluated as Grade II. Conclusions Occipitocervical fusion via cervical pedicle fixation assisted with O-arm navigation is a feasible and safe procedure with a vast range of indications.