Thoracolumbar Fascia Remodeling in Lumbar Spinal Stenosis: Translational Orthopedic Perspectives

Lumbar spinal stenosis (LSS) is a major cause of pain and disability, yet its pathophysiology remains incompletely understood. Although spinal decompression is the standard surgical treatment for LSS with disabling pain or with progressive neurological symptoms, clinical outcomes are often suboptimal, with reoperation required in 5-23% of cases. While degenerative changes in the vertebral canal have been extensively investigated, the potential contribution of the thoracolumbar fascia (TLF) has never been explored at the molecular level. We hypothesized that TLF undergoes extracellular matrix remodeling and inflammatory changes in LSS. Thoracolumbar fascia biopsies were collected from 14 patients undergoing spinal surgery (seven with LSS and seven controls with traumatic vertebral fractures). Total collagen content was quantified by hydroxyproline assay; collagen subtypes (I, III, VI and XII) by Western blotting; and inflammatory activity and extracellular matrix remodeling by ELISA quantification of TNF-α and MMP-2. LSS patients showed significantly higher hydroxyproline content (p = 0.026), indicating increased collagen deposition and fibrotic fascial remodeling, together with elevated MMP-2 levels (p = 0.038), consistent with active chronic extracellular matrix remodeling. TNF-α levels did not differ significantly between groups, although marked inter-individual variability was observed. Collagen subtype expression showed distinct trends but no significant differences. These findings provide the first molecular evidence of fibrotic remodeling and altered extracellular matrix turnover in TLF of LSS patients, supporting its role as an active contributor to disease pathophysiology and a potential diagnostic biomarker and therapeutic target.