Keyhole Foraminotomy via a Percutaneous Posterior Full-endoscopic Approach for Cervical Radiculopathy: An Advanced Procedure and Clinical Study.

Endoscopic cervical foraminotomy is increasingly used for cervical spondylotic radiculopathy (CSR), but there is great concern about radiation exposure because of the heavy dependence of this surgical method on fluoroscopy. The objective of this study was to introduce in detail an advanced surgical technique of keyhole foraminotomy via a percutaneous posterior full-endoscopic approach as a treatment for CSR and investigate its clinical outcomes. We retrospectively reviewed 33 consecutive patients with CSR who underwent keyhole foraminotomy via a percutaneous posterior full-endoscopic approach from October 2015 to April 2017. The patients' general characteristics, including operative time, blood loss, hospital stay, complications, and recurrence, were obtained. Clinical outcomes were evaluated using the visual analogue scale (VAS) for radicular pain, the neck disability index (NDI) for functional assessment, and the modified MacNab criteria for patient satisfaction. All operations were successfully performed (mean operation time, 62 min), with no measurable blood loss or severe related complications. The mean follow-up was 25 months. The VAS and NDI scores were significantly improved as compared with those in the preoperative period (preoperative vs. final follow-up: 7.6±1.6 vs. 3.83±7.34 for VAS, P<0.01; 69.5%±10.5% vs. 17.54%±13.40% for NDI, P<0.01). Of the 33 patients, 32 (97.0%) had good-to-excellent global outcomes and all patients obtained symptomatic improvement. In conclusion, keyhole foraminotomy via a percutaneous posterior full-endoscopic approach is an efficient, safe, and feasible procedure for the treatment of CSR. Its simplified single-step blunt incision for localization appears to decrease radiation exposure risks.