Disc herniation another view of FORM
From the point of view of Form a direct compression of the nerve root in the foramen intervertebrale is practically impossible, except in:
- the cervical and upper thoracic regions
- or by extremely massive herniation by excruciating trauma's (exploding the disc) which are seldom seen in our practices
So where does that story come from? Is it a hoax or not?
Well yes and not completely, but very indirectly in my opinion
The complex vertebrae, foramen intervertebrale and its circulatory-vascular and meningeal and in the core nervous relation is indeed complex...not simple as suggested by the representation models, nor complicated ...just complex.
This is just one of the hundreds of examples as good or rather bad as any we see in the Medical literature or on the net: Courtesy of the Mayo Clinic 2017
Following this bipolar view translated in the public's and Medical first line help: back problem means neurosurgeons or orthopedic surgeons....the bones or the nerve guy's...see the polarity?
I really like this picture
Bones or Nerves?
The complexity brings us, even if we want to reduce it and focus a a single phenomenon as a ruptured disc, to look at several dimensions...
The meninges, the circulatory story, the inflammation process, the mechanics etc....
I already wrote some stuff about that one so have a look on:
EVEN ON THE INFLAMMATION...FROM A PRACTICAL VIEW
HELL? IS EVERYTHING DONE FOR LINKEDIN AND FACEBOOK LEVEL?
NAAAEH,
LET'S TALK ABOUT THE FORAMEN INTERVERTEBRALE AND ITS FORM
To start with a peculiar structure of the form that makes the foramen intervertebrale such a special cookie, particularly for the Common-wealth people... because probably they'd never heard of this, or in a strange distorted way....
Probably it is due to language, but I could not evict to notice, repetitively in the Common wealth that there exists a strong trend to only read English writing authors and take them for granted.
And that puts us in a bit of a delicate position, as I wrote in
The world of anatomy really changed in the last 150 years, due to adaptations in the medical curriculum mostly. The problem being that 'one can only recognize what one knows'.
Thus knowledge not being taught and stripped out of the books for several generations in a row, had an exponential effect... of simplification and extreme over the top modeling...Virtualization
To begin with the foramen intervertebrale is a bony opening between two vertebrae all right....in a skeleton, in a full body alive or dead, the foramen is stuffed from here to Tokyo...
It is in most cases closed on the inside and on the outside by two fascial structures that Forestier described in his doctoral thesis of 1922: operculae of Forestier, operculum internum and operculum externum, structures that several of the professional anatomical drawers had already drawn but never named, actually an interesting observation and typical example of "You can only recognize what you know".
Front page copy of Thesis of Forestier 1922
Most anatomical drawers were just very good artists but not anatomists nor medically schooled in any way... they drew what they saw without judgement and the anatomists or morphologists named the structures. The drawers drew the structures, the anatomists did not name them as they did not recognize them...until after 1922....
An early copy of Corning Notice both layers of the dura mater are still drawn and named, not as visceralis and parietalis but externa and interna, the opercuale are drawn in little black lines closing the foramen, Hofmann and Trolard are absent
Here is the version of 1923 still drawn and colored but the names disappeared, suddenly the Dura is just the sack
https://archive.org/details/lehrbuchdertopog00corn/page/68
is the address where to find a online version of Corning of 1923.....Despite this Corning is a good anatomy book in my opinion it is one of the only that I know of that depicts and names the ligamentar structure in babies between diaphragm and testis for instance...Osteopaths should love that....
Testut images from the 1899 edition suggest-show even describes them partly but don't name them as a clear structure 1899!
Corning 1923, partially drawn and dissected just too far (partially cut away) but there are the Operculae
And then by the simplification and over the top modeling, it disappeared again from the teaching first, then from the books and then from the common anatomical nomenclature and finally general anatomical memory...
There was a modern exception though, by Nikolai Bogduk, he published in the eighties his book Clinical Anatomy of the Lumbar Spine and Sacrum, where he stated that the operculae did not exist but rather sometimes a transforaminal ligament which was inconstant... What really puts us before a question, what bodies did they dissect? Each time we looked at the operculae we find them without problem, but as we know what we are looking for, we dissect precociously and recognize them....
These schematic drawings are from my friend jeanPaul H?ppner for my Thesis and later adapted for the courses(these are the adapted ones)
1 Is the operculae of Forestier
2 Is the ligammenta dorsolateralia of Hofmann
3 Is the ligamentum sacroduralis anterior of Trolard
This an original of the D.O. thesis one
Now look at the following dissections the service has conserved in alcohol, some of the operculae were left intact and some dissected away as to see the difference (Look at the exit points of the nerves)
What is of interest for disc herniation is the following, the ligament of Hofmann or the dorsolateralia that maintain the original tissues (Dura mater externa) - ligamentum longitudinalis posterius and the dural sleeve of the radix as he is going through and forms a part of the operculum internum.
Here in a fresh dissection, the clear strut on the middle radix in between the two lifted by the pincets.
With a disc herniation this is the one (Hofmann) that is going to be pushed by the nucleus pulposus, provoking a serious traction on the dural root sleeve of the exiting radix spinalis.
And that is translated by a compression inside the nerve sheath disturbing the venous drainage of it....
Now since the 1990's it is known that this is the major component in organizing an inflammation reaction within the nerve roots connective tissues and vessels.
Which by the way are the major components of the nerve.....as can be seen on this electron microscopy image of a nerve section
Thus the problem is a circulatory and by that an inflammatory one, which conveys a compression within the nerve and not a compression of the disc herniation on the nerve root....AAARRGGHHH models and their oversimplification...
The circulatory component can be helped to get rid of the inflammation, by the venolymphatic pumping mechanism in the foramen intervertebrale between the two operculae of Forestier...but that is another long story, in the Evolutionary Applied Physiology course this takes a few hours...too long to write down here...
If you are troubled and want to think for yourself, read Sunderlands article from 1974 of the pressure changes within the foramen intervertebrale.. and think in FORM (J Neurosurg. 1974 Jun;40(6):756-63.
Meningeal-neural relations in the intervertebral foramen.
PMID: 4826601 DOI: 10.3171/jns.1974.40.6.0756
Please think morphology and research the venous system and arterial of this region it is too unknown to many osteopaths in my experience...
?Good luck...good hunt and good reasoning...I wish you
Cheers