=====Sequestered disk=====
A sequestered disk is an [[disc extrusion]] that has lost contiguity with the parent disk.


[[Disc herniation]] through a weakened subchondral vertebral endplate is an intravertebral disk herniation (ie, Schmorl node).

A lumbar [[intervertebral disc]] sequestration derives from the extrusion of [[disc]] material within the [[spinal canal]] or the contiguous foramina through a laceration that involves two anatomical layers: the [[annulus fibrosus]] of the intervertebral disc and the [[posterior longitudinal ligament]] (PLL). It is included in the radiological presentation of a [[lumbar disc herniation]] in up to 28% of cases
((Haddadi K, Qazvini HR. Posterior Epidural Migration of a Sequestrated Lumbar
Disk Fragment Causing Cauda Equina Syndrome in an Old Patient: A Case Report.
Clin Med Insights Case Rep. 2016 May 22;9:39-41. doi: 10.4137/CCRep.S39139.
PubMed PMID: 27257401; PubMed Central PMCID: PMC4877079.
)).