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Endoscopic discectomy is a minimally invasive treatment for disc herniation, protrusion, or extrusion. The goal of endoscopic discectomy is to provide relief from nerve root compression through the removal of herniated nuclear material. Endoscopic discectomy is also a therapeutic option for cases of advanced degeneration with proven discogenic pain. Endoscopic discectomy can be approached differently for the 2 basic types of disc herniations, contained and noncontained, both of which can be carried in an outpatient setting. The focus of this discussion is on contained herniations or disc bulges.
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Contained disc herniations within the annulus or posterior longitudinal ligament (typically 6-10 mm)
Unilateral leg pain greater than back pain
Radicular/neurological symptoms in a specific dermatomal distribution that correlates with MRI/CT/discography findings
Positive straight leg raising test or positive bowstring sign, or both
No improvement after 6 weeks of conservative therapy
Well maintained disc height of 60% or more
Alleviation of radicular pain with low volume selective nerve root block on the affected side at the operative level
Facet joint pain should be excluded
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Endoscopic discectomy should be strongly considered in patients with herniation within the far lateral recess beyond the intervertebral foramen. Such patients are difficult to treat with the traditional approach of microdiscectomy which may require removal of a large portion or the entire facet.
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Diffuse annular bulge involving the entire circumference of the vertebral body
Severe lateral recess stenosis
Calcified disc herniations
Severe degenerative facet disease
Ligamentum flavum hypertrophy
Free or extruded disc fragments within the spinal canal
Clinical evidence of significant progressive neurologic deficits and/or cauda equina syndrome
The existence of other pathologies or conditions, such as fracture, tumor, pregnancy, or active infection
An absolute contraindication for endoscopic discectomy includes significant (>= 3 mm) migration of disc fragment
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The central nucleus pulposus contains collagen fibers organized randomly, and elastin fibers arranged radially; these fibers are embedded in a highly hydrated aggrecan-containing gel.
Interspersed at a low density are chondrocyte-like cells sitting in a capsule within the matrix.
The annulus fibrosus is made up of a series of 15 to 25 concentric rings, or lamellae, with the collagen fibers lying parallel within each lamella. Elastin fibers lie between the lamellae.
The posterior lamellar annular layers are thinner than in the anterior spine, which assists in spinal flexion and extension but also predisposes the posterior annulus to disruption.
Trauma and internal disc derangement can lead to disc herniation, which consists of protrusion of the nucleus pulposus through the annulus fibrosus.
The morphology of the macroscopic annulus fibrosus and the microscopic anatomy both undergo changes in disc herniation.
The posterior concavity of the disc is often reduced or inverted, whereas the cellular structure itself in the annulus fibrosus undergoes a transformation from spindle-shaped cells to rounded chondrocytes at the area of ...