Disc protrusion

Disc protrusions are a type of disc herniation characterized by protrusion of disc content beyond the normal confines of the intervertebral disc, over a segment less than 25% of the circumference of the disc. The width of the base is wider than the largest diameter of the disc material which projects beyond the normal disc margins. The protrusion must not extend above or below the relevant vertebral endplates 4

A disc protrusion is also described in terms of its axial position, into central, subarticular, foraminal, extraforaminal or anterior locations 4.

Additionally the terms contained (outer annulus fibrosus laminae are intact) and non-contained (all laminae are deficient) are also sometimes used 4.

Terminology

Disc bulge is distinguished from a disc protrusion in that it involves more than 25% of the circumference.

A disc extrusion is distinguished from a disc protrusion in that the base of the protruded disc material is narrower than its 'dome'. Furthermore this material may extend above or below the disc level.

Note: A number of definitions of what exactly constitutes a disc protrusion have been proposed/used over the years, and it is important to realize that these differ substantially from one another 1-4.  At the time of writing (August 2016) the most recent and widely used terminology was proposed in 2014 by Fardon et al, and represents a consensus of the North American Spine Society, the American Society of Spine Radiology and the American Society of Neuroradiology 4

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Article information

rID: 6193
Synonyms or Alternate Spellings:
  • Protruding disk
  • Protruding disc
  • Disk protrusions
  • Disk protrusion
  • Disc protrusions

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Cases and figures

  • Figure 1: illustration
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  • Figure 2: disc protrusion
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  • Figure 3: axial disc herniation position
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  • Figure 4: sagittal localization
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  • Case 1: posterolateral focal protrusion
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  • Case 2: focal central disc protrusion
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  • Case 3: right paracentral disc protrusion
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  • Case 4: central focal disc protrusion
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  • Case 5
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  • Case 6
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  • Case 7
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  • Case 8
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