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Disc extrusion

Radswiki and Dr Frank Gaillard et al.

A disc extrusion a type of intervertebral disc herniation and is distinguished from a disc protrusion in that it:

has a broader dome (B) than neck (A), and / or
extends above of below the disc level (into the suprapedicular or infrapedicular zone)

It is associated with a defect in the annulus fibrosus which allows herniation of nucleus pulposus beyond the confines of the disc.

Extrusion can be in any axial direction and may migrate either superiorly or inferiorly. If the extrusion migrates but becomes separated from the rest of the herniation it is known as a intervertebral disc sequestration.

References

Article Information:

System: Musculoskeletal

Disc extrusion A disc extrusion has a narrow neck and is extrusion of nucleus polposus through an annular defect.

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Lumbar disc extrusion

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Sagittal Localisation The pedicle and disc are used as reference points to describe disc herniations. The pedicle and disc are used as reference points to describe disc herniations which may extend to:Disc level - confined to between the vertebral endplatesSuprapedicular - between superior endplate and superior border of pediclePedicular - at the level of the pedicleInfrapedicular - below loer margin of the pedicle to the inferior endplate.

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Axial disc herniation position Axial localisationMost sizable disc herniations will occupy more than one zone. CentralSubarticular ForaminalExtraforaminal or lateralAnterior

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Case 1 : foraminal disc extrusion : T2

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Case 2 : central disc extrusion : T2

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Case 3

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Case 4 : left lateral extraforaminal

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