Classification of lumbar spinal stenosis

Lumbar spinal stenosis (LSS) can be classified according to:

• aetiology
  • primary or congenital
    • rare
    • causes include:
      • idiopathic
      • achondroplasia.
      • hypochondroplasia
      • diastrophic dwarfism
      • Morquio's syndrome
      • hereditary exostosis
      • cheirolumbar dysostosis
  • secondary or acquired
    • causes include:
      • degenerative
      • Iatrogenic post-surgical
      • metabolic Paget's disease, fluorosis
      • post traumatic
      • stenosis due to spondylolisthesis
  • combined
    • congenital with secondary degenerative changes
      
      
• anatomy
  • central
    • occurs at the level of the intervertebral disc with midline sagittal narrowing
  • within the lateral recess
    • occurs when the traversing nerve root is compressed beneath the superior articular process of the inferior vertebra, i.e. beneath the thickened facet joint.
  • in the foramen
    
    
• typical and complex lumbar spinal stenosis
  • typical
    • no previous lumbar spine operation or radiographic evidence of instability
  • complex
    • previous lumbar spine operation with evidence of radiographic instability

Reference:

1. Rajagopal TS, Marshall RW. Focus on understanding and treating spinal stenosis 2010.