Fact-sheet: Congenital lumbar spinal stenosis


Updated on 04/19/2018 at 5:08 PM

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Definition

Constitutional lumbar spinal stenosis

  • radiologic measurements to be correlated with clinical findings: low back pain relieved by flexion
  • decompensation due to acquired degenerative changes.
  • sagittal, coronal, or bidirectional narrowing
  • central and/or lateral recess and/or foraminal narrowing

Clinical features

Low back pain relieved by flexion.

Radiography

Central canal narrowing:

  • frontal radiograph: reduced interpedicular distance or absence of the normal increase in interpedicular distance from L1 to L5.
  • sagittalization or excessive visibility of the posterior facet joint spaces (bilateral, over at least 3 consecutive levels).
  • lateral radiograph: shortened pedicles.

CT

Central stenosis:

  • anteroposterior diameter of the bony canal (slice through the closed bony ring at the lower part of the pedicles): Normal > 14 mm, relative stenosis: 12–14 mm, absolute stenosis < 12 mm
  • interfacet transverse diameter (slice through the disc): d < 15 mm
  • decreased cross-sectional area of the bony canal (more reliable measurement on MRI)

Lateral stenosis:

  • trefoil appearance of the canal
  • anteroposterior diameter of the lateral recess reduced to 3–4 mm

MRI

Dural sac cross-sectional area:

  • Normal > 100 mm2
  • Relative stenosis < 100 mm2
  • Absolute stenosis < 75 mm2

Management

Medical treatment: analgesics, NSAIDs, physical therapy, lumbar bracing, epidural or foraminal injections

Surgical treatment in cases of motor or sensory deficit and/or cauda equina syndrome, severe neurogenic claudication (limited walking distance), or patient request due to intractable pain: laminectomy and partial facetectomy +/- fusion

Differential diagnosis

  • Acquired degenerative lumbar stenosis
  • PAD
  • Popliteal artery entrapment
  • Venous claudication
  • Diabetic, alcoholic, or other polyneuropathy
  • Chronic compartment syndrome
  • Sciatica