Common terms of degenarative spinal disease
1.Desiccation ---loss of disc water2.Disk bulge---circumferential enlargement of the disc contour in symmetric fashion
3.protrusion---a bulging disc that is eccentric to one side but <3mm beyond vertebral margin
4.large protrusion---disk protrusion that extends more than 3mm beyond the vertebral margin
5.extruded disk ---extention of nucleus pulposus through the annulus into the epidural space
6.free fragment(sequestration) ---epidural fragment of disk no longer attached to the parent disk
Disk herniation can occur with an intact but thinned annulus (similar to protrusion) or with frank rupture of the annulus and extrusion of the nucleus through the defect .The term disk prolapse has been used to describe a herniated disk covered by a few remainning annular fibres.