An in vivo model of ligamentum flavum hypertrophy from early‐stage inflammation to fibrosis

Multi-joint disease pathologies in the lumbar spine, including ligamentum flavum (LF) hypertrophy and intervertebral disc (IVD) bulging or herniation contribute to spinal stenosis (LSS), a highly prevalent condition characterized by symptomatic narrowing of canal. Clinical hypertrophic LF is loss elastic fibers increase collagen fibers, resulting fibrotic thickening scar formation. In this study, we created an injury model test hypothesis that needle scrape rat will result altered tissue geometry, matrix organization, composition inflammation. An initial pilot study was conducted evaluate effect size. Results indicate using 22G produced upregulation pro-inflammatory cytokine Il6 at 1 week post injury, increased expression Ctgf Tgfb1 8 weeks along with persistent presence infiltrating macrophages 1, 3, injury. integrity also altered, evidenced increases thickness Persistent multi-joint effects IVD, height adjacent level, degenerative IVD changes observed level. These results demonstrate produces structural molecular features histological changes, dependent on This may be useful for testing therapeutic interventions treatment LSS degeneration associated hypertrophy.