A novel C-Arm-free navigation-guided endoscopy-assisted extraforaminal decompression for L5 radiculopathy with far-out syndrome: a surgical technical note.

We describe a C-arm-free, O-arm-based navigation-guided endoscopy-assisted extraforaminal decompression using a navigated burr in a 74-year-old woman with L5 radiculopathy due to far-out syndrome. Navigated instruments were used to plan the skin entry point and accurately target the extraforaminal L5 root corridor. Under endoscopic visualization, a navigated high-speed diamond burr was used to drill the hypertrophic transverse process, followed by meticulous perineural soft-tissue release from the foramen to the extraforaminal zone. No intraoperative complications occurred. The operative time was 78 minutes, and the estimated blood loss was 50 mL. Postoperative computed tomography (CT) and plain radiographs confirmed adequate decompression of the extraforaminal region. Clinically, the patient reported marked improvement in right L5 radicular pain, with resolution of preoperative numbness on standing and disappearance of intermittent claudication. At the 6-month follow-up, she was able to walk more than 1 km without claudication; sensory disturbance in the L5 dermatome had almost completely resolved and Visual Analogue Scale (VAS) score for leg pain (0-100 mm) improved from 65 mm preoperatively to 23 mm at 1 year follow-up. Posterolateral C-arm-free endoscopic extraforaminal decompression using O-arm navigation demonstrates a feasible and minimally invasive option for far-out syndrome, simplifying access to the deep extraforaminal corridor, minimizing soft-tissue trauma, and eliminating continuous fluoroscopic radiation to the surgical team.