A Novel Contrast-Enhanced Magnetic Resonance Neurography–Based Spatial Classification and Algorithmic Strategy for Unilateral Biportal Endoscopic Discectomy in Lumbar Disc Herniation

Abstract

Introduction: Although unilateral biportal endoscopic (UBE) discectomy has become increasingly popular for lumbar disc herniation (LDH), the optimal surgical approach remains controversial for different spinal levels and herniation locations. This study aimed to establish a novel contrast-enhanced magnetic resonance neurography (CE-MRN) –based classification system for LDH and propose corresponding surgical strategies for UBE discectomy.

Methods: This retrospective study included 284 patients with LDH who underwent UBE discectomy between March 2023 and March 2024. Patients were classified according to the proposed CE-MRN–based system, and surgical approaches were selected accordingly. Clinical outcomes were assessed using visual analog scale (VAS) scores, the Oswestry Disability Index (ODI), and the modified Macnab criteria during a minimum 12-month follow-up.

Results: At 12 months postoperatively, the mean VAS-back score improved from 5.3 (SD 2.6) to 0.7 (SD 0.7), the mean VAS-leg score improved from 7.4 (SD 2.2) to 0.3 (SD 0.5), and the mean ODI improved from 58.4 (SD 8.0) to 12.5 (SD 2.5) (all p <0.001). The rate of excellent or good outcomes according to the modified Macnab criteria was 92.96%. Twenty-six patients developed postoperative complications, all of which resolved with appropriate management. Thirteen patients experienced recurrence, and four underwent revision surgery. Postoperative complications were significantly more frequent in Zone C/D lesions than in Zone A/B lesions (25.0% vs. 5.3%; p <0.001).

Conclusions: The proposed CE-MRN–based classification system and corresponding surgical algorithm provide a practical framework for surgical approach selection in UBE discectomy. Clinical outcomes support its safety, reproducibility, and effectiveness in the management of LDH.