“Double Compression” at L5 – S1: A Case Treated with a Minimally Invasive Spine Endoscopic Pain Procedure (MisEpp)

Abstract

Introduction: Lumbar disc herniation at L5–S1 may coexist with lateral recess narrowing caused by adjacent facet-related bony encroachment. When both structures contact or constrain the traversing S1 nerve root, the resulting anatomical configuration may be described as “double compression.” In this report, the term is used descriptively rather than as an established diagnostic entity. We describe a case of simultaneous anterior disc-related and posterolateral facet-related compression of the traversing S1 nerve root and the clinical outcome following targeted endoscopic decompression of both components. Case Presentation: A woman in her fifth decade with a 1-year history of refractory left lumbosacral radicular pain underwent lumbar magnetic resonance imaging (MRI) and a minimally invasive spine endoscopic pain procedure (MisEpp) via an interlaminar endoscopic approach. MRI demonstrated a large left paracentral L5 – S1 disc extrusion and marked medial encroachment of a sagittalized left facet complex into the lateral recess. Targeted bony decompression was performed by undercutting the medially encroaching articular process, followed by removal of the extruded disc fragment. Neural decompression was assessed endoscopically. Intraoperatively, the traversing left S1 nerve root was visibly compressed anteriorly by the extruded disc and posterolaterally by the facet-related medially encroaching bony margin. After targeted bony decompression and discectomy, the nerve root was freely mobile and pulsatile, with no residual disc or bony compression. Radicular pain resolved by 2 weeks. The Oswestry Disability Index (ODI) improved from 54% preoperatively to 14% at 3 months. Conclusions: This case illustrates a potential dual-compression pattern in which disc herniation and facet-related lateral recess encroachment coexist at L5–S1. Although this case does not establish that combined decompression is superior to discectomy alone, it highlights the potential value of carefully assessing the lateral recess and facet morphology when planning treatment for selected patients with lumbar disc herniation.