Clarifying the nomenclature of intervertebral disc degeneration and displacement: from bench to bedside.

As a significant determinant of low back pain, intervertebral disc degeneration (IDD) has attracted more and more attention of both investigators and physicians. Disc herniation, termed as intervertebral disc displacement, is amongst the most prevalent spinal diseases closely linked with IDD. Due to the same origins and similar pathophysiology, the ambiguity regarding the similarity and difference of IDD and intervertebral disc displacement thus remains. The aim of this study was to clarify the nomenclature of IDD and disc herniation in terms of molecular etiology, pathophysiology, nature history and clinical outcomes. Collectively, IDD is a type of multifaceted, progressive spinal disease with or without clinical symptoms as back pain, characterized by extracellular matrix and the integrity of NP and AF lost, fissures formation. Disc herniation (termed as intervertebral disc displacement) is a type of spinal disease based on IDD or not, with local pain and/or sciatica due to mechanical compression and autoimmune cascades upon the corresponding nerve roots. Clarifying the nomenclature of intervertebral disc degeneration and displacement has important implications both for investigators and for physicians.