Objective: We hypothesize that within the intervertebral disc (IVD), a niche exists comprising the nucleus pulposus and the inner layer of the annulus fibrosus
and the cartilage endplate.
The disc joint is composed of three major parts: cartilaginous vertebral endplates that cap the bodies of the vertebrae, a fibrous annulus fibrosus that is located circumferentially between the vertebral bodies, and a thick gel-like nucleus pulposus in the center bounded by the fibers of the annulus fibrosus.
When the intervertebral disc is healthy, the nucleus is confined within the fibers of the annulus fibrosus.
Migration of the Nucleus Pulposus intra-durally requires perforation of the Annulus Fibrosus
and the posterior longitudinal ligament.
a fibro-gelatinous mass composed of 80%-90% water, collagen, and a mucopolysaccharide matrix); and the peripheral annulus fibrosus (formed by the concentric alternating lamellae of obliquely oriented collagenous fibers).
Structural variation of the anterior and posterior annulus fibrosus in the development of human lumbar intervertebral disc.
The ID is composed of a gelatinous structure called nucleus pulposus surrounded by a fibrous-resistant structure called annulus fibrosus.
Due to the geometry of the ID we can admit that this pressure is a sum of two pressures: the pressure on the nucleus pulposus Pn and the pressure on the annulus fibrosus [P.
Dehydration of the nucleus pulposus reduces its hydrostatic pressure and exposes the annulus fibrosus
to direct compressive forces, which eventually results in annular failure and fissuring.
The outside of the disk is a fibrous substance called the annulus fibrosus
Mitral disease seen in association with fen-phen lesions included 3 cases with floppy MV, 2 cases with rheumatic heart disease, 1 case with calcific mitral annulus fibrosus
, and 1 with superimposed infectious endocarditis (Figure 5).
This patented technology is used to seal the access site in the annulus fibrosus
following lumbar spine microdiscectomy.