LAUSR

Previous studies have implicated the proinflammatory To the Editor: Lumbar spinal canal stenosis (LSCS) is a common disease among older individuals. Hypertrophic factors including interleukin (IL)-1a, IL-6, tumor necrosis lumbar ligamentum flavum (LLF) plays a vital role in the pathogenesis of LSCS. The physiological LLF is a kind of dense connective tissue with thickness of 2 to 4 mm, which is mainly composed of fibroblasts and extracellular matrix (ECM). ECM contains elastic, collagen fibers and ground substances. The distribution characteristics of fibers show that a large number of elastic fibers are mixed with a small amount of the collagen fibers; mainly type I and type III collagen fibers. These fibers are arranged tightly and regularly along the direction of column’s axis. The LLF is located in the dorsal part of the dura mater of the spinal canal, and it attaches to the upper border and lower parts of anterior surfaces of the laminas. The hypotrophy of LLF is the consequence of several factors such as aging, inflammatory process, stress loading and genetic predisposition. Once the hypertrophy of LLF occurs, it can cause the stenosis for the central spinal canal, nerve root canal and intervertebral foramen. This pathology can lead to low back pain, sciatica, and even urinary and bowel disorders.