Spinal stenosis is a bony or soft-tissue narrowing of the spinal canal or the intervertebral foramina with pressure on the spinal cord, the dural sac or the nerve roots. The lumbar form in the lower spine is the most common.
Characteristic is neurogenic claudication with load-dependent back and leg complaints that worsen when standing and walking and improve when sitting or bending forwards. Causes are frequently degenerative changes such as spondylosis, disc protrusions, hypertrophic facet joints and a thickened ligamentum flavum.