Full-Endoscopic Lumbar Discectomy vs Standard Discectomy: A Noninferiority Study on Clinically Relevant Changes.

Background: Surgery for lumbar disc herniation (LDH) has had a remarkable technological development during the past 20 years. Microscopic discectomy has traditionally been the gold standard method to treat symptomatic LDH before the introduction of full-endoscopic lumbar discectomy (FELD). The FELD procedure allows unsurpassed magnification and visualization and is currently the most minimally invasive surgical technique. In this study, FELD was compared with standard surgery for LDH, with a focus on medically relevant changes in patient-reported outcome measures (PROMs).

Purpose: The purpose of this study was to investigate whether FELD is noninferior to other surgical methods for LDH surgery in the most common PROMs, including postoperative leg pain and disability, while still reaching the necessary thresholds for relevant clinical and medical improvements.

Methods: Patients undergoing a FELD procedure at the Sahlgrenska University Hospital, Gothenburg, Sweden, between 2013 to 2018 were included. A total of 80 (41 men and 39 women) patients were enrolled. The FELD patients were matched 1:5 to controls from the Swedish spine register (Swespine) who had a standard microscopic or mini-open discectomy surgery. PROMs, including the Oswestry Disability Index (ODI) and the Numerical Rating Scale (NRS), as well as the patient acceptable symptom states (PASS) and the minimal important change (MIC), were used to compare the efficacy of the 2 surgical approaches.

Results: The FELD group achieved medically relevant and significant improvements noninferior to standard surgery within the predefined thresholds of MIC and PASS. No differences could be found in disability measured by ODI FELD -28.4 (SD 19.2) vs standard surgery -28.7 (SD 18.9) or leg pain NRS FELD -4.35 (SD 2.93) vs standard surgery -4.99 (SD 3.12). All intragroup score changes were significant.

Conclusions: The FELD results are not inferior to standard surgery 1 year postoperatively after LDH surgery. There were no medically significant differences regarding MIC achieved or final PASS in any of the measured PROMs, including leg pain, back pain, or disability (ODI) between the surgical methods.

Clinical Relevance: The present study highlights that FELD is noninferior to standard surgery in clinically relevant PROMs.