Materiały źródłowe

• #1 Spinal Stenosis – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK441989/

  Spinal stenosis is a condition characterized by the compression of the nerve roots by a number of pathologic factors, leading to symptoms such as pain, weakness, and numbness. […] Spinal stenosis is a condition in which the nerve roots are compressed by a number of pathologic factors, leading to symptoms such as pain, numbness, and weakness. […] Spinal stenosis is common with aging but predicting which individual will develop symptoms is not possible. In most cases, the degenerative process can be controlled by changes in lifestyle. […] Spinal stenosis can be caused by congenital or acquired etiologies. Only 9% of the cases result from congenital etiologies. […] Acquired stenosis occurs primarily from trauma, degenerative changes, iatrogenic causes, and systemic processes. […] Spinal stenosis is a disease process that results from the narrowing of the vertebral spinal canal and the lateral recesses. This often leads to the compression of the structures located within the spinal canal, including the spinal cord, nearby nerve tissue, and cerebrospinal fluid. There are multiple factors that can lead to the narrowing. This includes bulging or protrusion of the intervertebral disc, herniation of the nucleus pulposus posteriorly, epidural fat deposition, hypertrophy of posterior longitudinal ligament, or the ligamentum flavum, and hypertrophy of the facet joints. […] Spinal cord injury can result in cord lead major complications such as myelopathic syndrome or cauda equina syndrome.

• #1 Lumbar Spinal Stenosis: Pathophysiology and Treatment Principle: A Narrative Review

  https://pmc.ncbi.nlm.nih.gov/articles/PMC7595829/

  Degenerative lumbar spinal stenosis refers to the narrowing of the spinal canal due to degenerative changes in spinal joints, intervertebral discs, and ligamentum flavum. […] Degenerative lumbar spinal stenosis is a progressive disease that involves all the movement segments of the spine. The relative instability initiated by degeneration of the intervertebral disc leads to hypermobility of the vertebral segments, resulting in increased pressure on the posterior facet joints, followed by a narrowing of the intervertebral disc space, an increased extension angle, and hypertrophy of the facet joints, especially the hypertrophy of the superior articular process. […] Calcification or thickening of the yellow ligament is an important mechanism in stenosis. […] Consequently, this causes the stenosis of the spinal canal and compression of nerve structures, which may lead to intermittent neurogenic claudication due to congestion of the epidural venous blood and increased vascular pressure.

• #1 Lumbar Spinal Stenosis: Pathophysiology, Biomechanics, and Innovations in Diagnosis and Management

  https://www.fortunejournals.com/articles/lumbar-spinal-stenosis-pathophysiology-biomechanics-and-innovations-in-diagnosis-and-management.html

  The development of acquired LSS is a multifactorial process and understanding the pathophysiology is crucial to developing a plan for patients. Degenerative, a form of acquired lumbar stenosis, is a progressive disease that involves all aspects of the spine, presenting with different symptomatology depending on the region of the spine affected. The relative instability of the spine begins with degeneration of the intervertebral disc, causing hypermobility of the vertebral segments. Hypermobility of the vertebral segments leads to increased pressure on the posterior facet joints, leading to a narrower space between the discs, an altered angle of extension, and an enlargement of the facet joints, especially the superior articular process. Over time, these joints can become stiff and even fuse, a process called ankylosis.

• #1 Spinal stenosis | PPT

  https://www.slideshare.net/slideshow/spinal-stenosis-242372131/242372131

  Increased pressure on facet joints with disc space narrowing and increasing angles of extension. Hypertrophy of facet joints (sup articular process). Hypertrophic process results in local ankylosis. Calcification and hypertrophy of ligamentum flavum. Reduced spinal canal dimensions and compression of neural elements. […] Resultant venous congestion and hypertension likely responsible for intermittent neurological claudication.

• #1 Lumbar Spinal Stenosis, Clinical Presentation, Diagnosis, and Treatment | IntechOpen

  https://www.intechopen.com/chapters/50887

  The degenerative process can also be observed in this region, where diffuse disc bulging can also be seen, associated with loss of height all leading to a reduced diameter of the vertebral canal. The zygapophyseal joints are also directly associated with foramen stenosis, because their hypertrophy may or may not be associated with the presence of osteophytes, thus causing radicular compression. […] The progression of the degenerative disease still remains truly unknown. However, many concepts have already been postulated. The first one concerns the definition of instability; it is defined as excessive mobility, neural compression, or deformity. The presence of instability may be associated with a variety of clinical and anatomic manifestations. […] Kirkaldy and Willis described the degenerative process in terms of evolution and divided it into three phases. However, the duration of each stage is unknown. The first phase was described as a dysfunction in which the disc exhibits chiefly biochemical changes. The second phase was called instability in which degenerative processes in the disc lead to an increase in the segments motion; this is when disc herniation can occur. Finally, there is the stabilization phase in which disc height reduction, facet hypertrophy, and changes in the yellow ligament occur. This phase of disc degeneration is the most important for the development of the present study, because the aforementioned changes lead to a reduction of the vertebral canal diameter and to narrow lumbar spinal canal syndrome the disease that is the object of this study.

• #1

  https://www.orthobullets.com/spine/2037/lumbar-spinal-stenosis

  Lumbar Spinal Stenosis is a degenerative spinal condition characterized by the narrowing of the lumbar spinal canal due to a variety of bony or soft tissues structures. […] Narrowing of the lumbar spinal canal can be due to bony structures such as facet osteophytes, uncinate spur (posterior vertebral body osteophyte), and spondylolisthesis. […] It can also be due to soft tissue structures like herniated or bulging discs, hypertrophy or buckling of the ligamentum flavum, and synovial facet cysts. […] Cell, water, and proteoglycan content in the nucleus pulposus decreases with age. […] Degeneration of the intervertebral disk leads to diminished disk height and buckling/bulging of the anulus fibrosus. […] The anterior spinal column begins to have decreased ability to absorb stress, leading to an abnormal transfer of force to the posterior elements. […] Increased stress through the facets leads to facet joint hypertrophy, osteophyte formation, and ligamentum flavum buckling and hypertrophy. […] Combined changes lead to a narrowing of the spinal canal and compression of the neural elements.

• #1 Aetiology of the Lumbar Spinal Stenosis in Black Africans: Intraoperative Observations – Iranian Journal of Neurosurgery

  https://irjns.org/browse.php?a_id=4&slc_lang=en&sid=1&ftxt=1&html=1

  Lumbar canal stenosis is the narrowing of the central diameter of the lumbar canal or of the lateral intervertebral foramen. Stenosis caused by a combination of bone and soft tissues can be acquired or congenital. […] The main objective of this study was to describe and report from a surgical series, the intraoperative pathoanatomic finding involved in LSS among black African patients from various countries. […] The two main anatomic intraoperative observations were the ligamentum flavum hypertrophy and the zygapophyseal joint hypertrophy (95.5%) whether the stenosis were acquired, congenital or mixed. The stenosis was as well exclusively due to a ligamentum flavum hypertrophy (50%) or the zygapophyseal joint hypertrophy (7.5%). […] The role of the ligamentum flavum is then established in the occurrence of the LSS on Black African.

• #1 Lumbar Spinal Stenosis: Pathophysiology, Biomechanics, and Innovations in Diagnosis and Management

  https://www.fortunejournals.com/articles/lumbar-spinal-stenosis-pathophysiology-biomechanics-and-innovations-in-diagnosis-and-management.html

  Additional mechanisms also contribute to the pathophysiology of acquired lumbar spinal stenosis. For example, ligamentum flavum hypertrophy and joint tropism are two mechanisms described in the literature that are directly correlated to the development of LSS. Aleksic et al. demonstrated in their study of 60 patients, evenly divided between patients with lumbar discus hernia and lumbar spinal stenosis, ligamentum flavum hypertrophy was prevalent in all 30 patients with LSS demonstrating the direct association between the two conditions. Additionally, histological analysis revealed increased collagen content and decreased elastic fibers in the ligamentum flavum of LSS patients, leading to reduced elasticity and increased stiffness. These degenerative changes in the ligamentum flavum are significant contributors to the pathophysiology of LSS, emphasizing the role of ligamentum flavum hypertrophy in the development of the condition.

• #1 Lumbar Spinal Stenosis: Pathophysiology, Biomechanics, and Innovations in Diagnosis and Management

  https://www.fortunejournals.com/articles/lumbar-spinal-stenosis-pathophysiology-biomechanics-and-innovations-in-diagnosis-and-management.html

  Facet joint tropism refers to the asymmetry in the orientation of the facet joints on either side of the spine. This asymmetry can lead to uneven distribution of mechanical loads, potentially contributing to degenerative changes in the lumbar spine. Research has explored the relationship between facet joint tropism and LSS. For example, a study titled „Facet joint tropism, pelvic incidence and facet joint osteoarthritis in lumbar spinal stenosis” investigated this association. The researchers found that facet joint tropism is significantly associated with the development of facet joint osteoarthritis, which plays a crucial role in the pathogenesis of LSS. The study suggests that the asymmetrical orientation of facet joints may lead to uneven mechanical stress, accelerating degenerative changes and contributing to spinal canal narrowing.

• #1 Lumbar Spinal Stenosis: Pathophysiology, Biomechanics, and Innovations in Diagnosis and Management

  https://fortuneonline.org/articles/lumbar-spinal-stenosis-pathophysiology-biomechanics-and-innovations-in-diagnosis-and-management.html

  Facet joint tropism refers to the asymmetry in the orientation of the facet joints on either side of the spine. This asymmetry can lead to uneven distribution of mechanical loads, potentially contributing to degenerative changes in the lumbar spine. Research has explored the relationship between facet joint tropism and LSS. For example, a study titled „Facet joint tropism, pelvic incidence and facet joint osteoarthritis in lumbar spinal stenosis” investigated this association. The researchers found that facet joint tropism is significantly associated with the development of facet joint osteoarthritis, which plays a crucial role in the pathogenesis of LSS. The study suggests that the asymmetrical orientation of facet joints may lead to uneven mechanical stress, accelerating degenerative changes and contributing to spinal canal narrowing.

• #1 Lumbar Spinal Stenosis: Pathophysiology, Biomechanics, and Innovations in Diagnosis and Management

  https://fortuneonline.org/articles/lumbar-spinal-stenosis-pathophysiology-biomechanics-and-innovations-in-diagnosis-and-management.html

  In another study examined association between facet tropism and vertebral rotation in patients with degenerative lumbar disease and corroborated these findings, demonstrating that facet tropism is directly associated with vertebral orientation, further contributing to spinal instability by altering the natural biomechanics of the spine, compounding stenosis and contributing to symptom severity. […] The literature demonstrates that chronic inflammation and fibrosis also play a significant role in the pathophysiology of lumbar spinal stenosis. Several histological studies have revealed increased pro-inflammatory markers and matrix remodeling enzymes in the ligamentum flavum and facet joints, leading to tissue thickening and reduced spinal flexibility. In another investigation examining the effect of angiopoietin-like protein 2 (Angptl2) and the role of interleukin-6 (IL-6) on the inflammatory conditions in the ligamentum flavum in the pathogenesis of lumbar spinal canal stenosis, it was demonstrated how Angptl2 impacts the pathophysiology of LSS. Angptl2, which is a member of the angiopoietin-like protein family, is known to act as an inflammatory mediator. The researchers found that Angptl2 levels are significantly elevated in hypertrophied ligamentum flavum tissue compared to non-hypertrophied tissue in patients with LSS. This elevated Angptl2 expression appears to directly contribute to inflammation by upregulating the expression of IL-6, a cytokine associated with chronic inflammatory responses.

• #1 Molecular and Genetic Mechanisms of Spinal Stenosis Formation: Systematic Review

  https://www.mdpi.com/1422-0067/23/21/13479

  Spinal stenosis (SS) is a multifactorial polyetiological condition characterized by the narrowing of the spinal canal. This condition is a common source of pain among people over 50 years old. We perform a systematic review of molecular and genetic mechanisms that cause SS. The five main mechanisms of SS were found to be ossification of the posterior longitudinal ligament (OPLL), hypertrophy and ossification of the ligamentum flavum (HLF/OLF), facet joint (FJ) osteoarthritis, herniation of the intervertebral disc (IVD), and achondroplasia. FJ osteoarthritis, OPLL, and HLF/OLFLF/OLF have all been associated with an over-abundance of transforming growth factor beta and genes related to this phenomenon. OPLL has also been associated with increased bone morphogenetic protein 2. FJ osteoarthritis is additionally associated with Wnt/β-catenin signaling and genes. IVD herniation is associated with collagen type I alpha 1 and 2 gene mutations and subsequent protein dysregulation. Finally, achondroplasia is associated with fibroblast growth factor receptor 3 gene mutations and fibroblast growth factor signaling. Although most publications lack data on a direct relationship between the mutation and SS formation, it is clear that genetics has a direct impact on the formation of any pathology, including SS. Further studies are necessary to understand the genetic and molecular changes associated with SS.

• #1 Molecular and Genetic Mechanisms of Spinal Stenosis Formation: Systematic Review

  https://www.mdpi.com/1422-0067/23/21/13479

  Osteoblastogenesis is the increased proliferation of osteoblasts occurring due to the activation of regulatory proteins bone morphogenetic protein (BMP) and transforming growth factor-beta (TGF-β). BMP or TGF-β binds and activates the type 1 (RI) and type 2 (RII) receptors for these proteins (TGF-βRI/II; BMPRI/II). Aberrant activation of BMP and TGF-β signaling plays a central role in the development of OPLL. Many pathological changes, including mechanical stress, inflammatory response, negative regulation of transcription and metabolic pathways, and genetic mutations can cause activation of BMP and TGF-β signaling. […] In summary, activation of TGF-βRI/II or BMPRI/II leads to induction of SMAD2/3/4, SMAD1/5/8/4, and/or MAPK pathways, resulting in transcription of proteins such as aggrecan, Runx2, and Osterix. Subsequently, mesenchymal stem cells (MSCs), osteoblasts, and chondrocytes proliferate and differentiate, causing the formation of OPLL.

• #1 Lumbar Spinal Stenosis: Pathophysiology, Biomechanics, and Innovations in Diagnosis and Management

  https://www.fortunejournals.com/articles/lumbar-spinal-stenosis-pathophysiology-biomechanics-and-innovations-in-diagnosis-and-management.html

  The literature demonstrates that chronic inflammation and fibrosis also play a significant role in the pathophysiology of lumbar spinal stenosis. Several histological studies have revealed increased pro-inflammatory markers and matrix remodeling enzymes in the ligamentum flavum and facet joints, leading to tissue thickening and reduced spinal flexibility. In another investigation examining the effect of angiopoietin-like protein 2 (Angptl2) and the role of interleukin-6 (IL-6) on the inflammatory conditions in the ligamentum flavum in the pathogenesis of lumbar spinal canal stenosis, it was demonstrated how Angptl2 impacts the pathophysiology of LSS. Angptl2, which is a member of the angiopoietin-like protein family, is known to act as an inflammatory mediator. The researchers found that Angptl2 levels are significantly elevated in hypertrophied ligamentum flavum tissue compared to non-hypertrophied tissue in patients with LSS. This elevated Angptl2 expression appears to directly contribute to inflammation by upregulating the expression of IL-6, a cytokine associated with chronic inflammatory responses.

• #1 Lumbar Spinal Stenosis: Pathophysiology, Biomechanics, and Innovations in Diagnosis and Management

  https://www.fortunejournals.com/articles/lumbar-spinal-stenosis-pathophysiology-biomechanics-and-innovations-in-diagnosis-and-management.html

  Interleukin-6, a pro-inflammatory cytokine, is a major factor in promoting fibrosis and tissue thickening. When Angptl2 activates IL-6 expression in the ligamentum flavum, it initiates a cascade of cellular responses that increase collagen deposition and fibroblast activity. These processes lead to excessive fibrosis, which results in the loss of elasticity and thickening of the ligamentum flavum. This thickened ligament then encroaches into the spinal canal space, contributing to the neural compression characteristic of LSS.

• #1 The identification of novel gene mutations for degenerative lumbar spinal stenosis using whole-exome sequencing in a Chinese cohort | BMC Medical Genomics | Full Text

  https://bmcmedgenomics.biomedcentral.com/articles/10.1186/s12920-021-00981-4

  Degenerative lumbar spinal stenosis (DLSS) is a common lumbar disease that requires surgery. Previous studies have indicated that genetic mutations are implicated in DLSS. […] Whole-exome sequencing (WES) is a valuable research tool that identifies disease-causing genes and could become an effective strategy to investigate DLSS pathogenesis. […] DLSS etiology and patho-mechanisms remain unclear, but previous studies implicate genetic factors in DLSS. […] Therefore, the identification of pathogenic genes will provide novel therapeutic strategies for DLSS treatment. […] Our study revealed that deleterious mutations in several genes might contribute to DLSS etiology. By screening and confirming susceptibility genes using WES, we provided more information on disease pathogenesis. […] Several studies have identified candidate genes associated with lumbar disc degeneration.

• #1 Molecular and Genetic Mechanisms of Spinal Stenosis Formation: Systematic Review

  https://www.mdpi.com/1422-0067/23/21/13479

  The TGF-β1 gene is located in 19q13.2. This gene provides the instructions for the synthesis of a TGF-β1 protein. TGF-β1 produces biochemical signals that are responsible for various cellular activities such as cell growth and proliferation, cell maturation (differentiation), cell motility, and physiological cell death (apoptosis). TGF-β1 signaling is known to be associated with osteoarthritis, but contributing mutations have not been identified. […] Achondroplasia results from a mutation in the FGFR3 gene encoding one member of the FGFR subfamily with tyrosine kinase activity. The FGFR3 gene is responsible for the production of the FGFR3 protein, which converts cartilage into bone. There is a mutation SNP rs28931614 (G > A, C) at position 4p:1804392 in the gene for FGFR3. More than 97% of achondroplasia cases result from either a G-to-A or G-to-C transition, where Gly380 (GGG) codon changes to Arg (AGG or CGG) in the FGFR3 transmembrane domain. In 80% of cases, achondroplasia is not inherited but arises from a de novo mutation. All people with a single copy of the mutated FGFR3 gene have achondroplasia since this mutation has 100% dominance. The FGFR3 gene is one of the most frequently mutated in the human genome.

• #1 Lumbar Spine Stenosis: A Common Cause of Back and Leg Pain | AAFP

  https://www.aafp.org/pubs/afp/issues/1998/0415/p1825.html/1000

  In most cases, stenosis of the lumbar canal may be attributed to acquired degenerative or arthritic changes of the intervertebral discs, ligaments and facet joints surrounding the lumbar canal. These changes include cartilaginous hypertrophy of the articulations surrounding the canal, intervertebral disc herniations or bulges, hypertrophy of the ligamentum flavum and osteophyte formation. […] Compression of the microvasculature of the lumbar nerve roots, resulting in ischemia, is believed to be a major contributing factor in the development of neurogenic claudication. […] In the ischemic form, it is theorized that transient ischemia occurs in compressed lumbosacral roots when increased oxygen demand occurs during walking. […] Some investigators have postulated that the pathologic changes that result in lumbar canal stenosis are the result of so-called micro-instability at the articular surfaces surrounding the canal. Micro-instability refers to minute, abnormal repetitive motion of the joints that link adjacent vertebra. These movements are clinically silent yet may result in progressive loss of strength in the joint capsules and lead to reactive bony and cartilaginous hypertrophy, thickening or calcification of the ligamentum flavum, or subluxation of one vertebra on another (spondylolisthesis), all of which may contribute to narrowing of the lumbar canal.

• #1 Lumbar Spinal Stenosis: Pathophysiology and Treatment Principle: A Narrative Review

  https://pmc.ncbi.nlm.nih.gov/articles/PMC7595829/

  As the lumbar is extended, the spinal canal becomes narrower and the neural tissue is compressed, and simultaneously, the metabolic rate of nerve roots by the lower extremity movement increases, but the increase in blood flow cannot catch up with it. […] In lumbar spinal stenosis, when the nerve roots are under increased pressure in the spinal canal, neural ischemia and defective nerve conduction can occur. […] Symptoms can also occur due to venous congestion and may contribute to the etiology of lumbar spinal stenosis involving two or more segments. […] Degenerative lumbar spinal stenosis primarily proceeds due to the degenerative process of the vertebral joint and yellow ligament.

• #1 Spinal stenosis pathophysiology – wikidoc

  https://www.wikidoc.org/index.php/Spinal_stenosis_pathophysiology

  Spinal stenosis may result from any condition that narrows the spinal canal and compresses nerve roots. […] The most common cause of spinal stenosis is degenerative joint disease. […] The spinal cord and nerve roots depend on a constant blood supply to perform axonal signaling. […] Conditions that interfere, either directly or indirectly, with the blood supply will cause malfunction of the transmission pathway. […] It initiates a cascade of events in the gray matter and white matter and results in hypoperfusion. […] The following results in autonomic dysfunction leading to neurogenic shock (triad of hypotension, bradycardia and peripheral vasodilation) and eventually hemorrhagic necrosis. […] The extent of necrosis depends on the severity of the compression, and blood flow. […] The tissue responses by gliosis, demyelination, and axonal loss. […] This results in injury to the white matter (myelinated tracts) and the gray matter (cell bodies) in the cord with loss of sensory reflexes (pinprick, joint position sense, vibration, hot/cold, pressure) and motor function.

• #1

  https://step2.medbullets.com/neurology/120247/lumbar-spinal-stenosis

  narrowing of the central canal, lateral recess, or neural foramen […] mechanical compression of the lumbar spinal cord can result in nerve ischemia […] in the extended position, there is further narrowing of the lumbar spine, resulting in neurogenic claudication […] neurogenic claudication may also result from increased metabolic demand from the already compressed lumbar spine.

• #1 Neurogenic Claudication: Pathogenesis and Clinical Findings | Calgary Guide

  https://calgaryguide.ucalgary.ca/neurogenic-claudication-pathogenesis-and-clinical-findings/neurogenic-claudication_2_er/

  Neurogenic Claudication: Pathogenesis and Clinical Findings Spinal stenosis: Abnormal narrowing of the spinal canal. […] compression Vascular compromise Edema, ischemia Symptomatic spinal nerves […] Hip extension Buckling of ligamentum flavum and overlapping of adjacent vertebral laminae and facets canal size compression Worsening of symptoms […] Modification of symptoms with movement and position Exercise vasodilation of spinal arteries compression Hip flexion Stretching of ligamentum flavum, reduction of overlap of adjectent vertebral laminae and facets, enlarged foramina canal size compression.

• #1 Meet the Lumbar Spinal Stenosis Challenge – Page 2 of 8 – The Rheumatologist

  https://www.the-rheumatologist.org/article/meet-the-lumbar-spinal-stenosis-challenge/2/

  The rapid reversibility of leg pain with a change in posture is strong evidence for the important role of vascular obstruction as a primary component of the pathogenesis of neurogenic claudication. […] The longer the duration of the vascular compromise, the more persistent and total becomes the neural dysfunction. […] Alleviation of vascular congestion can normalize the function of the sciatic nerve and diminish leg pain. […] Therefore, the goal of therapy is to maximize neural blood flow and restore nerve function.

• #1 Lumbar Spine Stenosis: A Common Cause of Back and Leg Pain | AAFP

  https://www.aafp.org/pubs/afp/issues/1998/0415/p1825.html

  Compression of the microvasculature of the lumbar nerve roots, resulting in ischemia, is believed to be a major contributing factor in the development of neurogenic claudication. Wilson classified neurogenic claudication into two major types based on the putative pathophysiologic mechanism: postural or ischemic. Postural neurogenic claudication is induced when the lumbar spine is extended and lordosis is accentuated, whether at rest or during exercise in the erect posture. With extension of the spine, degenerated intervertebral discs and thickened ligamenta flava protrude posteriorly into the lumbar canal, producing transient compression of the cauda equina. In the ischemic form, it is theorized that transient ischemia occurs in compressed lumbosacral roots when increased oxygen demand occurs during walking. […] Other acquired conditions that can be associated with lumbar canal stenosis as a result of osseous or fibrocartilaginous hypertrophy include fluorosis, hyperparathyroidism, Paget’s disease, ankylosing spondylitis, Cushing’s disease and acromegaly.

• #1 Lumbar Spinal Stenosis, Clinical Presentation, Diagnosis, and Treatment | IntechOpen

  https://www.intechopen.com/chapters/50887

  It is postulated that the improvement associated with flexion and extension is directly related to stretching or folding of the yellow ligament. Trunk flexion causes tension in this ligament, thus increasing its diameter, whereas trunk extension causes it to fold into the spinal canal, thus further narrowing the canal that is already narrowed by the degenerative process.

• #1 Lumbar Spinal Stenosis, Clinical Presentation, Diagnosis, and Treatment | IntechOpen

  https://www.intechopen.com/chapters/50887

  The progression of the disease is uncertain: according to Johnson, 70% of patients remain stable for a 4-year period, 15% improve, and 15% tend to become worse. The progression to cauda equina syndrome is extremely rare, but must always be investigated, particularly because of the possibility of other causes, but also because it is an absolute indication for urgent surgery. […] The best diagnostic test to distinguish both syndromes was described by Van Gelderen. He had patients riding a stationary bicycle. Patients with lumbar canal stenosis tolerate the exercise, because the forward-leaning position causes symptoms to improve, whereas patients with vascular claudication do not tolerate the exercise, because the hypoxia caused by the underlying disease causes pain and peripheral cyanosis.

• #1 Lumbar Spinal Stenosis: Pathophysiology, Biomechanics, and Innovations in Diagnosis and Management

  https://www.fortunejournals.com/articles/lumbar-spinal-stenosis-pathophysiology-biomechanics-and-innovations-in-diagnosis-and-management.html

  Lumbar spinal stenosis comprises central canal, lateral recess, and foraminal subtypes, each characterized by unique pathophysiological mechanisms attributed to the region-specific narrowing of the spinal canal. Central canal stenosis refers to the narrowing of the central spinal canal, typically involving the cauda equina in the lumbar region. The primary pathophysiological mechanisms are associated with degenerative changes, such as hypertrophy of the ligamentum flavum, disc bulging, and osteoarthritic alterations in the facet joints. Ligamentum flavum hypertrophy occurs due to collagen remodeling and increased mechanical load over time, resulting in thickening that reduces the central canal space. Additionally, disc degeneration and vertebral instability can lead to degenerative spondylolisthesis, wherein a vertebra slips forward, further narrowing the canal and increasing the likelihood of nerve compression. These changes primarily lead to symptoms such as neurogenic claudication, which presents as lower extremity pain, numbness, or weakness relieved by lumbar flexion.

• #1 The 5 Most Innovative Treatments for Spinal Stenosis – Commons Clinic

  https://commonsclinic.com/innovations-spinal-stenosis/

  Spinal stenosis often begins with changes in the spine that leads to increased instability. These changes can result in hypermobility in certain spinal joints and a significant overgrowth of the facet joints, located at the back of the spine, primary contributors to lumbar spinal stenosis symptoms. […] Understanding spinal stenosis and what might increase the risk of developing it is essential for effectively diagnosing and managing the condition. Spinal stenosis most commonly affects the lower back and neck. Its causes are generally categorized into two main types: acquired and congenital. […] Acquired spinal stenosis (often referred to as degenerative spinal stenosis) is the more common form and typically develops due to wear and tear changes in the spine as you age. As a common treatment for spinal stenosis in elderly patients, doctors first assess these age-related changes, which can include bulging discs, arthritic joints, and thickened ligaments. These conditions can protrude into the spinal canal and narrow the space available for the spinal cord and nerve roots.

• #1 Lumbar Spinal Stenosis, Clinical Presentation, Diagnosis, and Treatment | IntechOpen

  https://www.intechopen.com/chapters/50887

  As was described by Kirkaldy and Willis, the cascading degeneration does not have a definite phase, but in the stabilization phase, lumbar canal stenosis can be observed. It may or may not cause symptoms, but if symptoms do occur, this is commonly observed in patients above 50 years of age. Currently, the most commonly performed type of spine surgery in patients over 65 years old in the United States is decompression of cauda equina roots. […] Vertebral canal stenosis, as defined by Verbiest, corresponds to narrowing of the vertebral canal, the lateral recess, and the intervertebral foramen, causing compression of neural elements. Vertebral canal stenosis can be divided into two main groups: congenital and acquired. These main groups were further subdivided: congenital stenosis into idiopathic and achondroplasic, and acquired stenosis into degenerative, combined, spondylotic, iatrogenic, post-traumatic, and metabolic.

• #1 Lumbar Spine Stenosis: A Common Cause of Back and Leg Pain | AAFP

  https://www.aafp.org/pubs/afp/issues/1998/0415/p1825.html/1000

  Lumbar spine stenosis most commonly affects the middle-aged and elderly population. Entrapment of the cauda equina roots by hypertrophy of the osseous and soft tissue structures surrounding the lumbar spinal canal is often associated with incapacitating pain in the back and lower extremities, difficulty ambulating, leg paresthesias and weakness and, in severe cases, bowel or bladder disturbances. […] Narrowing of the lumbar canal has many potential causes, and various classification schemes have been devised in order to better describe the pathophysiology of this condition. A classification system proposed by Verbiest categorizes the multiple causes of lumbar stenosis into two types: conditions that lead to progressive bony encroachment of the lumbar canal (including developmental, congenital, acquired and idiopathic causes) or stenosis produced by nonosseous structures such as ligaments, intervertebral discs and other soft tissue masses. For practical purposes, however, the etiologies of lumbar stenosis can be divided into congenital or acquired forms.

• #1 Pathophysiology of Lumbar Spinal Stenosis

  https://www.e-neurospine.org/journal/view.php?number=491

  Lumbar spinal stenosis can be caused by various disorders, both congenitally and secondarily. It results from hypertrophy or enlargement of bony structures, ligament, and other surrounding tissues and cause characteristic clinical symptoms and signs such as radiculopathy and intermittent neurogenic claudication. The pathophysiologic mechanisms known to be associated with these clinical symptoms and signs are arterial insufficiency, venous congestion, inflammatory response, biomechanical factors, and segmental spinal instability. […] For this, treating physician should be aware of anatomy and pathophysiology of lumbar spinal stenosis with regards to various changes taking place in each individual. This review is to summarize the basic up-to-dated literature on pathophysiology of lumbar spinal stenosis in order to provide necessary knowledge required for the proper management of patients with lumbar spinal stenosis.

• #1

  https://link.springer.com/article/10.1007/s12178-007-9003-2

  Patients with LSS have disk and zygapophyseal joint degeneration, which can lead to a degenerative spondylolisthesis. The resultant mechanical instability can cause a dynamic radiculopathy by imposing a stretch on the nerve root as it passes through the unstable level. This instability may result in further vascular and inflammatory changes, which contribute to the multifactorial pathogensis of symptoms.

• #1 Meet the Lumbar Spinal Stenosis Challenge – The Rheumatologist

  https://www.the-rheumatologist.org/article/meet-the-lumbar-spinal-stenosis-challenge/

  Spinal stenosis is a disorder characterized by insufficient room in the spinal canal for the neural elements. Most commonly, acquired degeneration of the anatomic structures of the lumbar spine results in narrowing of the central spinal canal, the lateral recesses, or the neural foramina. […] A basic understanding of the pathogenesis of this disorder is essential for making therapeutic decisions for the corresponding form of spinal stenosis. What might be appropriate for an intervertebral disc herniation (a form of acutely acquired spinal stenosis) will not necessarily be effective for spinal narrowing that has been decades in the making. […] The earliest changes occur in the intervertebral discs that lose their structural integrity and start to flatten. The resulting biomechanical insufficiency results in transfer of stresses posteriorly to the ligaments and facet joints. The response to the added weight results in the development of osteophytes on facet joints and vertebral endplates, as well as the redundancy and thickening of the ligamentum flavum. […] The mechanism of radicular pain production in spinal stenosis is incompletely understood. Individuals with similar degrees of canal narrowing experience different intensities and locations of pain. Mechanical compression of nerve roots may cause electrophysiological alterations in nerve conduction. However, slow, persistent compression is associated with neural adaptation that does not lead to symptoms. Simple compression of the neural elements alone does not fully explain the generation of radicular pain. Vascular compromise associated with arterial, capillary, and venous obstruction plays a substantial role in the development of neurogenic claudication.

• #1 Spinal Stenosis: Pathophysiology, Clinical Diagnosis, and Differential Diagnosis | Musculoskeletal Key

  https://musculoskeletalkey.com/spinal-stenosis-pathophysiology-clinical-diagnosis-and-differential-diagnosis/

  This causes narrowing of the spinal canal and potential neural impingement. […] The term spinal stenosis describes the anatomic narrowing of the spinal canal. […] A number of cadaver and animal studies have attempted to elucidate the mechanism of these symptoms. […] The presence of stenosis increases with aging; however, it often does not produce any symptoms. […] What causes pain in some individual with mild spinal stenosis and no symptoms in others with severe stenosis? […] The rate at which these changes are occurring also appears to be important.

• #2 Lumbar spinal stenosis – Wikipedia

  https://en.wikipedia.org/wiki/Lumbar_spinal_stenosis

  Lumbar spinal stenosis (LSS) is a medical condition in which the spinal canal narrows and compresses the nerves and blood vessels at the level of the lumbar vertebrae. […] The precise cause of LSS is unclear. Narrowing of spinal structures in the spinal cord such as the central canal, the lateral recesses, or the intervertebral foramen (the opening where a spinal nerve root passes) must be present, but are not sufficient to cause LSS alone. […] LSS may also be caused by osteophytes, osteoporosis, a tumor, trauma, or various skeletal dysplasias, such as with pseudoachondroplasia and achondroplasia. […] Spinal stenosis may be congenital (rarely) or acquired (degenerative), overlapping changes normally seen in the aging spine. […] The ligamentum flavum (yellow ligament), an important structural component intimately adjacent to the posterior portion of the dural sac (nerve sac) can become thickened and cause stenosis.

• #2 Lumbar Spinal Stenosis: Pathophysiology, Biomechanics, and Innovations in Diagnosis and Management

  https://fortuneonline.org/articles/lumbar-spinal-stenosis-pathophysiology-biomechanics-and-innovations-in-diagnosis-and-management.html

  The development of acquired LSS is a multifactorial process and understanding the pathophysiology is crucial to developing a plan for patients. Degenerative, a form of acquired lumbar stenosis, is a progressive disease that involves all aspects of the spine, presenting with different symptomatology depending on the region of the spine affected. The relative instability of the spine begins with degeneration of the intervertebral disc, causing hypermobility of the vertebral segments. Hypermobility of the vertebral segments leads to increased pressure on the posterior facet joints, leading to a narrower space between the discs, an altered angle of extension, and an enlargement of the facet joints, especially the superior articular process. Over time, these joints can become stiff and even fuse, a process called ankylosis.

• #2 Lumbar Spinal Stenosis, Clinical Presentation, Diagnosis, and Treatment | IntechOpen

  https://www.intechopen.com/chapters/50887

  The degenerative process can also be observed in this region, where diffuse disc bulging can also be seen, associated with loss of height all leading to a reduced diameter of the vertebral canal. The zygapophyseal joints are also directly associated with foramen stenosis, because their hypertrophy may or may not be associated with the presence of osteophytes, thus causing radicular compression. […] The progression of the degenerative disease still remains truly unknown. However, many concepts have already been postulated. The first one concerns the definition of instability; it is defined as excessive mobility, neural compression, or deformity. The presence of instability may be associated with a variety of clinical and anatomic manifestations. […] Kirkaldy and Willis described the degenerative process in terms of evolution and divided it into three phases. However, the duration of each stage is unknown. The first phase was described as a dysfunction in which the disc exhibits chiefly biochemical changes. The second phase was called instability in which degenerative processes in the disc lead to an increase in the segments motion; this is when disc herniation can occur. Finally, there is the stabilization phase in which disc height reduction, facet hypertrophy, and changes in the yellow ligament occur. This phase of disc degeneration is the most important for the development of the present study, because the aforementioned changes lead to a reduction of the vertebral canal diameter and to narrow lumbar spinal canal syndrome the disease that is the object of this study.

• #2

  https://www.orthobullets.com/spine/2037/lumbar-spinal-stenosis

  Lumbar Spinal Stenosis is a degenerative spinal condition characterized by the narrowing of the lumbar spinal canal due to a variety of bony or soft tissues structures. […] Narrowing of the lumbar spinal canal can be due to bony structures such as facet osteophytes, uncinate spur (posterior vertebral body osteophyte), and spondylolisthesis. […] It can also be due to soft tissue structures like herniated or bulging discs, hypertrophy or buckling of the ligamentum flavum, and synovial facet cysts. […] Cell, water, and proteoglycan content in the nucleus pulposus decreases with age. […] Degeneration of the intervertebral disk leads to diminished disk height and buckling/bulging of the anulus fibrosus. […] The anterior spinal column begins to have decreased ability to absorb stress, leading to an abnormal transfer of force to the posterior elements. […] Increased stress through the facets leads to facet joint hypertrophy, osteophyte formation, and ligamentum flavum buckling and hypertrophy. […] Combined changes lead to a narrowing of the spinal canal and compression of the neural elements.

• #2 Aetiology of the Lumbar Spinal Stenosis in Black Africans: Intraoperative Observations – Iranian Journal of Neurosurgery

  https://irjns.org/article-1-4-en.html

  Lumbar spinal stenosis (LSS) is a common condition. This congenital or acquired stenosis has multiple etiologies. […] The ligamentum flavum hypertrophy is the main cause of LSS in black Africans. Studies to determine the mechanism of hypertrophy will be useful in order to initiate preventive treatment.

• #2 Molecular and Genetic Mechanisms of Spinal Stenosis Formation: Systematic Review

  https://www.mdpi.com/1422-0067/23/21/13479

  Similar to OPLL, increased TGF-β1 concentrations are thought to contribute to HLF/OLF and subsequently lumbar spine stenosis. Connective tissue growth factor has also been associated with HLF and is known to be stimulated by TGF-β1 as well. Increased TGF-β activity causes increased proliferation of fibroblasts and osteoblasts, which increase extracellular matrix production and thus lead to stenosis. The accumulation of extracellular matrix is enhanced by the inhibitory and stimulatory effects of TGF-β on the expression of matrix metalloproteases and their inhibitors, respectively. […] The leading causes of osteoarthritis are related to TGF-β, SMAD, and Wnt/β-catenin signaling pathways, which destroy the balance between anabolic and catabolic activity in the articular cartilage and lead to irreversible degradation of the extracellular matrix.

• #2 Lumbar Spinal Stenosis: Pathophysiology, Biomechanics, and Innovations in Diagnosis and Management

  https://fortuneonline.org/articles/lumbar-spinal-stenosis-pathophysiology-biomechanics-and-innovations-in-diagnosis-and-management.html

  In another study examined association between facet tropism and vertebral rotation in patients with degenerative lumbar disease and corroborated these findings, demonstrating that facet tropism is directly associated with vertebral orientation, further contributing to spinal instability by altering the natural biomechanics of the spine, compounding stenosis and contributing to symptom severity. […] The literature demonstrates that chronic inflammation and fibrosis also play a significant role in the pathophysiology of lumbar spinal stenosis. Several histological studies have revealed increased pro-inflammatory markers and matrix remodeling enzymes in the ligamentum flavum and facet joints, leading to tissue thickening and reduced spinal flexibility. In another investigation examining the effect of angiopoietin-like protein 2 (Angptl2) and the role of interleukin-6 (IL-6) on the inflammatory conditions in the ligamentum flavum in the pathogenesis of lumbar spinal canal stenosis, it was demonstrated how Angptl2 impacts the pathophysiology of LSS. Angptl2, which is a member of the angiopoietin-like protein family, is known to act as an inflammatory mediator. The researchers found that Angptl2 levels are significantly elevated in hypertrophied ligamentum flavum tissue compared to non-hypertrophied tissue in patients with LSS. This elevated Angptl2 expression appears to directly contribute to inflammation by upregulating the expression of IL-6, a cytokine associated with chronic inflammatory responses.

• #2 Lumbar Spinal Stenosis: Pathophysiology, Biomechanics, and Innovations in Diagnosis and Management

  https://fortuneonline.org/articles/lumbar-spinal-stenosis-pathophysiology-biomechanics-and-innovations-in-diagnosis-and-management.html

  Interleukin-6, a pro-inflammatory cytokine, is a major factor in promoting fibrosis and tissue thickening. When Angptl2 activates IL-6 expression in the ligamentum flavum, it initiates a cascade of cellular responses that increase collagen deposition and fibroblast activity. These processes lead to excessive fibrosis, which results in the loss of elasticity and thickening of the ligamentum flavum. This thickened ligament then encroaches into the spinal canal space, contributing to the neural compression characteristic of LSS.

• #2 The identification of novel gene mutations for degenerative lumbar spinal stenosis using whole-exome sequencing in a Chinese cohort | BMC Medical Genomics | Full Text

  https://bmcmedgenomics.biomedcentral.com/articles/10.1186/s12920-021-00981-4

  In this study, HLA-DRB1 and PARK2 were identified as susceptibility genes associated with a predisposition to DLSS. […] Our genetic data partially agreed with previous studies; however, specific gene-related DLSS mechanisms require further investigation. […] This study also identified ACTR8, AOAH, BCORL1, MKRN2, NRG4, and NUP205 genes associated with DLSS. […] Several other DLSS candidate genes were also identified in this study, including GPRIN2, MYOT, and PDE4DIP, etc. […] Our study had several limitations. […] However, our immediate remit is to increase cohort size to increase statistical power and identify more susceptible genes. […] We identified several candidate gene mutations potentially associated with DLSS in Chinese patients using WES for the first time. Further verification of our data may help develop molecular-based approaches to aid DLSS diagnosis and treatment.

• #2 Meet the Lumbar Spinal Stenosis Challenge – Page 2 of 8 – The Rheumatologist

  https://www.the-rheumatologist.org/article/meet-the-lumbar-spinal-stenosis-challenge/2/

  The rapid reversibility of leg pain with a change in posture is strong evidence for the important role of vascular obstruction as a primary component of the pathogenesis of neurogenic claudication. […] The longer the duration of the vascular compromise, the more persistent and total becomes the neural dysfunction. […] Alleviation of vascular congestion can normalize the function of the sciatic nerve and diminish leg pain. […] Therefore, the goal of therapy is to maximize neural blood flow and restore nerve function.

• #2 Lumbar Stenosis, Back Pain, Sciatica Advice by a World-Renowned Spine Expert | ChiroGeek.com

  https://www.chirogeek.com/Stenosis%20101/stenosis.html

  In simple terms, lumbar spinal stenosis (LSS) is a condition that occurs when the passageways within the vertebral column become narrowed and constrict the nerve roots contained within them. Such a constriction may, but not always, result in disabling lower extremity pain, limited ability to walk and stand, and, indirectly, severe lower back pain. […] Although developmental anomalies (problems from birth) of the spine may account for some cases, LSS is typically an acquired condition that results from degenerative changes within the spine, such as disc bulging, ligamentum flavum thickening, and/or facet joint hypertrophy (bony thickening). Specifically, any one of these factors, alone or in combination, may narrow the passageways within the lumbar spine and crush the nerve root(s) contained within. Once a nerve root is compressed by a certain magnitude of force and for a certain duration of time, it can turn that nerve into a chronic pain generator, which the patient experiences as radicular pain and/or lower extremity dysfunction.

• #2 The 5 Most Innovative Treatments for Spinal Stenosis – Commons Clinic

  https://commonsclinic.com/innovations-spinal-stenosis/

  Congenital spinal stenosis is present from birth and involves a naturally narrow spinal canal. While congenital stenosis alone may not cause symptoms, it can make the spinal cord and nerve roots more vulnerable to acquired stenosis later in life. Only about 9 percent of spinal stenosis cases are due to congenital causes. […] Spinal stenosis doesn’t just appear out of nowhere; it’s often the result of gradual changes in your spine’s structure. These include: Intervertebral discs, which is the wearing down of the cushions between the bones in your spine; Enlargement of facet joints, which are the joints that connect the bones of your spine; Thickening of the ligamentum flavum, a ligament that connects the vertebrae in the spine; Growth of bony bumps called osteophytes; Bulging or protruding spinal discs; Spondylolisthesis, a condition in which one vertebra slips over the one below it.

• #2

  https://link.springer.com/article/10.1007/s12178-007-9003-2

  Degenerative lumbar stenosis is a common source of pain and disability in the elderly. […] There is a multifactorial pathogenesis to lumbar stenosis and its symptoms, and thus, there are multiple management approaches available. […] We know that the pathogenesis of LSS is multifactorial. If narrowing and compression were the sole pathologic entities of LSS, decompressive surgery would be a panacea. There are vascular, biochemical, and biomechanical factors that contribute to the symptoms of LSS, and thus, need to be considered as much as the physical compression. […] The inflammatory cascade is another component of this multifactorial pathogenesis. Over the years, multiple inflammatory mediators have been implicated in the pathogenesis of radicular symptoms due to disk herniations, including phospholypase A2, cytokines, nitric oxide, lactate, and immune cells.

• #3 Lumbar Stenosis, Back Pain, Sciatica Advice by a World-Renowned Spine Expert | ChiroGeek.com

  https://www.chirogeek.com/Stenosis%20101/stenosis.html

  Lateral stenosis is a condition that occurs when either the nerve root canal (nerve root canal stenosis) or the neural foramen (neural foramina stenosis) becomes significantly narrowed secondary to osseous and/or ligamentous thickening, which is typically secondary to degenerative change. A significant narrowing of either of these canals will may result in unilateral radicular pain and not the bilateral radicular pain and/or neurogenic claudication that is seen with central stenosis.

• #3 Lumbar Spinal Stenosis, Clinical Presentation, Diagnosis, and Treatment | IntechOpen

  https://www.intechopen.com/chapters/50887

  As was described by Kirkaldy and Willis, the cascading degeneration does not have a definite phase, but in the stabilization phase, lumbar canal stenosis can be observed. It may or may not cause symptoms, but if symptoms do occur, this is commonly observed in patients above 50 years of age. Currently, the most commonly performed type of spine surgery in patients over 65 years old in the United States is decompression of cauda equina roots. […] Vertebral canal stenosis, as defined by Verbiest, corresponds to narrowing of the vertebral canal, the lateral recess, and the intervertebral foramen, causing compression of neural elements. Vertebral canal stenosis can be divided into two main groups: congenital and acquired. These main groups were further subdivided: congenital stenosis into idiopathic and achondroplasic, and acquired stenosis into degenerative, combined, spondylotic, iatrogenic, post-traumatic, and metabolic.

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