1. 2018;21;E215-E223Minimally Invasive Full-Endoscopic Posterior Cervical Foraminotomy Assisted by O-Arm-Based Navigation
   Retrospective Study
   Chao Zhang, MD, PhD, Junlong Wu, MD, PhD, Chuang Xu, MD, Wenjie Zheng, MD, PhD, Yong Pan, MD, PhD, Changqing Li, MD, PhD, and Yue Zhou, MD, PhD.

BACKGROUND: Navigated percutaneous endoscopic cervical discectomy (PECD) is a promising minimally invasive surgery for treating cervical spondylotic radiculopathy. PECD has been described as a safe, effective, and minimally invasive method for patients with radiculopathy, but it comes with a steep learning curve. Due to the limited field of vision, anatomic localization is difficult for surgeons until using the O-arm based navigation. In this study, patients with radiculopathy due to foraminal disc herniation or foraminal stenosis in the lower cervical spine underwent the single level full endoscopic posterior cervical foraminotomy procedure assisted by O-arm-based navigation.

OBJECTIVE: The purpose of this study was to evaluate the clinical, radiological outcome and the factors predicting an excellent outcome of patients who underwent full endoscopic posterior cervical foraminotomy procedure assisted by O-arm-based navigation.

STUDY DESIGN: A retrospective analysis of consecutively prospectively collected data.

SETTING: This study was conducted by a university-affiliated hospital in a major Chinese city.

METHODS: Forty-two patients who had single-level foraminal disc herniation or foraminal stenosis were retrospectively reviewed. Radicular arm pain was the most common presenting symptom in patients. All patients underwent full-endoscopic posterior cervical foraminotomy assisted by O-arm-based navigation. Clinical outcomes were assessed by the visual analog scale (VAS) for neck and radicular arm pain, neck disability index (NDI), and the short form-36 health survey questionnaire (SF-36) in the immediate preoperative period, immediately postoperative, and at the final follow-up. The clinical parameters and radiological parameters included cervical curvature (CA), segmental angle (SA), and range of motion (ROM), which were assessed preoperatively and at the last follow-up.

RESULTS: The mean follow-up for the patients was 15 months. There were no perioperative complications. The VAS score for radicular arm pain and neck pain and the NDI score improved significantly in all of the patients. The SF-36 score reflected significant improvement in all 8 domains. Excellent and good outcomes were achieved in 38 out of 42 patients. The cervical curvature range of motion (CA-ROM) statistically and significantly improved at the final follow-up period compared with the preoperative period. The SA was less kyphotic after PECD at the final follow-up. The postoperative CA and CA-ROM improved but did not significantly change. On the univariate analysis, patients with a symptom duration of less than 3 months had a better outcome than patients with a symptom duration of more than 3 months (excellent, 83.33% vs. 50.00%).

LIMITATIONS: This was a retrospective study with medium follow-up outcomes (mean 15 months).

CONCLUSIONS: The results of this study show that the full endoscopic posterior foraminotomy assisted by O-arm-based navigation is a safe and effective option for cervical radiculopathy, with the advantages of a minimally invasive method. Patients with symptom duration less than 3 months had a better outcome than patients with symptom duration more than 3 months.

KEY WORDS: Minimally invasive, cervical foraminotomy, endoscopic, navigation, O-arm, percutaneous endoscopic cervical discectomy