LINKS:
Doug's Current Treatment Diary:
Basic Anatomy of the Lumbar Disc:
Disc Herniation - How it evolves:
Disc Herniation continued: Pain!
RESEARCH:
Disc Herniation & Radiculopathy Facts:
Pathophysiology of Degenerative Disc Disease:
IMAGES:
MRI - Cervical Anatomy & axial post ACDF:
THE ORIGIN of the DISC HERNIATION: Internal Disc Disruption.
It
all starts with a little non-painful tearing of the inner layer of the disc: These
Annular Disc Tears (aka: Internal disc
Disruption) may start because of sudden trauma (like an auto
accident or fall), trauma over time (such as someone who
has done heavy 'labor' for many years) or idiopathically (for
reasons unknown). Degenerative Disc
Disease (DDD) is very often a precursor to the onset of disc tearing.
(DDD will be addressed at a later time.)
In 1987 a classification system for rating Disc Tears was developed. I will now try to demonstrate this system of degeneration. The above photo shows a Grade 1 disc tear. The disc has started tearing from the inside out and as progressed through 1/3 of the disc. The patient may feel no pain yet.
Here the disc has been torn even
further. When the disc tear is seen extending 2/3's of the way out from
the center, towards the outside, its said to be a 'Grade 2 Annular Disc Tear'.
I may add that these tears I'm showing here only can be seen with a test called
a Discogram. MRI may or may not pick these tears up.
Here the disc is ripped all
the way to the outer layer of the annulus. This is called a Grade 3
Annular Disc Tear. These types of injuries may show up on MRI. A
'HIZ Phenomenon', a very same area of 'bright
white' on the posterior of the disc, it the 'tell-tale' sign of the grade 3 or 4
Disc Tear.