Dr.
Nachemson makes a VERY convincing case when he presents
6 lines of reasoning, supported by 17 references, to
support his contention that the intervertebral disc is
the most likely source of back pain, including the
primary research completed by Smyth and Wright in 1958
(2). Regarding the work by Smyth and Wright, Dr.
Nachemson notes:
"Investigations have been performed in which thin nylon
threads were surgically fastened to various structures
and around the nerve root. Three to four weeks after
surgery these structures were irritated by pulling on
the threads, but pain resembling that which the patient
had experienced previously could only be registered only
from the outer part of the annulus" of the disc.
It had been established
in the 1930s that herniation of the lumbar disc could
put pressure on the nerve root or the cauda equina,
resulting in sciatica. However, Dr. Nachemson in this
context is saying something dramatically different;
He's Claiming That A Non-Herniated Disc Problem Was
Causing Back Pain.
At the time (1976),
claiming the intervertebral disc was capable of
initiating pain was new and not only that, Nachemson
claiming the disc to be the most probable
source of back pain was both surprising AND
revolutionary.
At the time, most
authoritative reference texts stated the intervertebral
disc was not even innervated with pain afferents and
therefore not capable of initiating pain.
As an example,
rheumatology professor Malcolm Jayson, MD (editor) in
the 1987 text titled The Lumbar Spine and Back Pain,
states
"in the mature
human spine no nerve endings of any description
remain in the nucleus pulposus or annulus fibrosis of
the intervertebral disc
in any region of the vertebral column."
(3)
A conclusion we now know to be 100% false.
Support for Dr. Nachemson's contention of disc pain came
in 1981 when anatomist and physician Nikoli Bogduk
published an extensive review of the literature on the
topic of disc innervation, along with his own primary
research, in the prestigious Journal of Anatomy (4). Dr.
Bogduk notes:
"In the absence of any
comprehensive description of the innervation of the
lumbar intervertebral discs and their related
longitudinal ligaments, the present study was undertaken
to establish in detail the source and pattern of
innervation of these structures."
Dr. Bogduk and his team concluded decisively:
"The Lumbar Intervertebral Discs Are
Supplied By A Variety Of Nerves."
and
"Clinically, The Concept Of 'Disc Pain'
Is Now Well Accepted."
Dr. Bogduk returned in 1983 updating his research notes
in SPINE, stating more specifically :
"THE LUMBAR INTERVERTEBRAL DISCS ARE INNERVATED
posteriorly by the sinuvertebral nerves, but laterally
by
branches of the ventral rami and grey rami communicantes…
The posterior longitudinal ligament is innervated by the
sinuvertebral nerves and
the anterior longitudinal ligament by branches of the
grey rami.
Lateral and intermediate branches of the lumbar dorsal
rami supply the iliocostalis lumborum and longissimus
thoracis, respectively.
Medial branches supply the multifidus,
intertransversarii mediales, interspinales, interspinous
ligament, and the lumbar zygapophysial joints."
"The
distribution of the intrinsic nerves of the lumbar
vertebral column
systematically identifies those structures that are
potential sources of primary low-back pain."
Adding to the growing momentum of this "disc-pain"
concept… In 1987, SPINE published Dr. Vert Mooney's
Presidential Address of the International Society for
the Study of the Lumbar Spine. It was delivered at the
13th Annual Meeting of the International Society for the
Study of the Lumbar Spine, May 29-June 2, 1986, Dallas,
Texas, and titled (6):
Where Is the Pain Coming From?
In this
article, Dr. Mooney notes the following:
"Six weeks to 2
months is usually enough to heal any
stretched ligament, muscle tendon, or joint capsule.
Yet we know that 10%
of back 'injuries' do not resolve
in 2 months and that they do become chronic."
"Anatomically the
motion segment of the back is made up of two synovial
joints and a unique relatively avascular tissue found
nowhere else in the body - the intervertebral disc. Is
it possible for the disc to obey different rules of
damage than the rest of the connective tissue of the
musculoskeletal system?"
"Persistent pain in
the back with referred pain to the leg
is largely on the basis of abnormalities within the
disc."
Chemistry of the disc
is based on the relationship between
mucopolysaccharide production and water content.
"Mechanical events
can be translated into chemical events related to pain."
An important aspect
of disc nutrition and health is the
mechanical aspects of the disc related to the fluid
mechanics.
"Mechanical activity
has a great deal to do with the
exchange of water and oxygen concentration" in the disc.
The pumping action
maintains the nutrition and biomechanical function of
the intervertebral disc. Thus, "research substantiates
the view that unchanging posture, as a result of
constant pressure such as standing, sitting or lying,
leads to an interruption of pressure-dependent transfer
of liquid. Actually the human intervertebral disc lives
because of movement."
"The fluid content of
the disc can be changed by mechanical activity, and the
fluid content is largely bound to the proteoglycans,
especially of the nucleus."
"In summary, what is
the answer to the question of where is the pain coming
from in the chronic low-back pain patient? I believe its
source, ultimately, is in the disc. Basic studies and
clinical experience suggest that mechanical therapy is
the most rational approach to relief of this painful
condition."
"Prolonged rest and
passive physical therapy modalities
no longer have a place in the treatment of the chronic
problem."
This model presented by Dr. Mooney in this paper goes on
to discuss:
The intervertebral disc
as the primary source of both back
pain and referred leg pain. The disc apparently becomes
painful because of altered biochemistry, which
sensitizes the pain afferents that innervate it.
Disc biochemistry is
altered because of mechanical problems,
especially mechanical problems that reduce disc
movement.
Therefore, the most
rational approach to the treatment of chronic low back
pain is mechanical therapy that restores the motion to
the joints of the spine, especially to the disc.
Prolonged Rest Is
Inappropriate Management
Additional support for
the disc being the primary source of back pain was
presented by Dr. Stephen Kuslich in the prestigious
journal Orthopedic Clinics of North America in April
1991 (7). The title of his article is:
The Tissue Origin of Low Back Pain and Sciatica:
A Report of Pain Response to Tissue Stimulation
During Operations on the Lumbar Spine Using Local
Anesthesia
These authors performed 700 lumbar spine
operations using only local anesthesia to
determine the tissue origin of low back and leg pain,
and they present the results on 193 consecutive patients
studied prospectively. Several of their critically
important findings for you include:
"Back pain could be produced by several lumbar
tissues, but by far, the most common tissue or origin
was the outer layer of the annulus fibrosis."
The lumbar fascia could be "touched or even cut
without anesthesia."
Any pain derived from muscle pressure was "derived
from local vessels and nerves, rather than
the muscle bundles themselves."
"The normal, uncompressed, or unstretched nerve root was
completely insensitive to pain."
"In spite of all that has been written about muscles,
fascia, and bone as a source of pain, these
tissues are really quite insensitive."
Very
recently in 2006, physician researchers from Japan
published in SPINE the
results of an extremely sophisticated
immunohistochemistry study of the sensory innervation of
the human lumbar intervertebral disc (8). The
article is titled:The
Degenerated Lumbar Intervertebral Disc is Innervated
Primarily by Peptide-Containing Sensory Nerve Fibers in
Humans
The Japanese
researchers note:
"Many investigators have reported the existence of
sensory nerve fibers in the intervertebral discs of
animals and humans, suggesting that the intervertebral
disc can be a source of low back pain."
"Both inner and outer layers of the degenerated lumbar
intervertebral disc are innervated by pain sensory nerve
fibers in humans."
Pain
neuron fibers are found in all human discs that have
been removed because they are the source of a patient's
chronic low back pain.
The
nerve fibers in the disc, found in this study,
"indicates that the disc can be a source of pain
sensation."
The information and data
offered by these studies from across 30 years of
published research in the most highly respected journals
CLEARLY and UNEQUIVOCALLY demonstrates that…
The Annulus Of The Intervertebral Disc Is Primarily
Responsible For The
Majority Of Chronic Low Back Pain.
Above (6), Dr Vert Mooney notes in his
Presidential Address to the International Society for
the Study of the Lumbar Spine that, "basic studies
and clinical experience suggest that mechanical therapy
is the most rational approach to relief of this painful
[intervertebral disc] condition."
________________________________________
In
Support Of Dr. Mooney's Perspective,
Four Such Studies Are Reviewed Here:
In 1985, Dr. Kirkaldy-Willis, a Professor
Emeritus of Orthopedics and director of the Low-Back
Pain Clinic at the University Hospital, Saskatoon,
Canada, published an article in the journal Canadian
Family Physician (9).
In this study, the authors present
the results of a prospective observational study of
spinal manipulation in 283 patients with chronic low
back and leg pain.
All 283 patients in
this study had failed prior conservative and/or
operative treatment, and they were all totally disabled.
These patients were given a "two or three week regimen
of daily spinal manipulations by an experienced
chiropractor."
These
authors determined a good result from manipulation to
be:
"Symptom-free with no restrictions for work or other
activities."
OR
"Mild intermittent pain with no restrictions for work or
other activities."
81% of the
patients with referred pain syndromes subsequent to
joint dysfunctions achieved the "good" result.
48% of the
patients with nerve compression syndromes, primarily
subsequent to disc lesions and/or central canal spinal
stenosis, achieved the "good" result.
Dr. Kirkaldy-Willis
attributed this clinical outcome to Melzack and Wall's
1965 "Gate Theory of Pain." He noted that the
manipulation improved motion, which improved
proprioceptive neurological input into the central
nervous system, which in turn blocked pain.
Dr. Kirkaldy-Willis'
conclusion from the study was:
"The physician who makes use of this [manipulation]
resource
will provide relief for many back pain patients."
In 1990, Dr. TW Meade published the results of a
randomized comparison of chiropractic and hospital
outpatient treatment in the treatment of low back pain.
This trial involved 741 patients and was published in
the prestigious British Medical Journal (10). It was
titled:
Low
back pain of mechanical origin:
Randomized comparison of chiropractic and hospital
outpatient treatment
The patients in this study
were followed for a period between 1 – 3 years. Nearly
all of the chiropractic management involved traditional
joint manipulation. Key points presented in this article
include:
"Chiropractic treatment
was more effective than hospital outpatient management,
mainly for patients with chronic or severe back pain."
"There is, therefore,
economic support for use of chiropractic in low back
pain, though the obvious clinical improvement in pain
and disability attributable to chiropractic treatment is
in itself an adequate reason for considering the use of
chiropractic."
"Chiropractic was
particularly effective in those with fairly intractable
pain-that is, those with a history of severe pain."
"Patients treated by
chiropractors were not only no worse off than those
treated in hospital but almost certainly fared
considerably better and that they maintained their
improvement for at least two years."
"The results leave little
doubt that chiropractic
is more effective than conventional hospital outpatient
treatment."
Most importantly, the above
studies indicate that the primary tissue origin of
chronic back pain is the intervertebral disc.
This study by Meade notes
that the benefit of chiropractic is seen primarily
in patients that are suffering from severe chronic pain.
This would suggest that
chiropractic manipulation is affecting the pain
afferents arising from the disc. A plausible theory to
support this is found below… at the end of this
presentation.
Also, the Meade study authors definitively note that if
all back pain patients without manipulation
contraindications were referred for chiropractic instead
of hospital treatment, there would be significant annual
treatment cost reductions, a significant reduction in
sickness days during the following two years, and a
significant savings in social security payments.
In 2003,
the highly regarded orthopedic journal SPINE published a
randomized clinical trial involving the nonsteroidal
anti-inflammatory cox-2 inhibiting drugs Vioxx or
Celebrex v. needle acupuncture v. chiropractic
manipulation in the treatment of chronic neck and back
pain (11). The title of the article is: Chronic
Spinal Pain: A Randomized Clinical Trial Comparing
Medication, Acupuncture, and Spinal Manipulation
In this study chiropractic was over 5 times
more effective than the medications and better than
twice as effective as needle acupuncture in the
treatment of chronic spine pain.
Chiropractic was able to accomplish these
clinical outcomes without any reported adverse effects.
One year after the completion of this 9-week
clinical trial, 90% of the original trial participants
were re-evaluated to assess their clinical status.
The authors discovered that only those who
received chiropractic during the initial randomization
benefited from a long-term stable clinical outcome. The
results of this second assessment were published in 2005
(12).
An
important question to consider…
How does joint
manipulation reduce chronic back pain
arising from the intervertebral disc?
I find that the most
plausible explanation is offered by Canadian orthopedic
surgeon WH Kirkaldy-Willis in the first edition
(1983) of his book titled Managing Low Back Pain.
Dr.
Kirkaldy-Willis describes the biomechanics of how the
two facet joints form a three-joint complex with the
intervertebral disc.
He notes
that "motion at one site must reflect motion at the
other two." It is probable that spinal manipulation
primarily mechanically affects the facet articulations.
According
to Dr. Kirkaldy-Willis, such facet motion would
necessarily cause motion in the intervertebral disc.
Consistent with the published data noted above, this
would improve fluid mechanics of the disc, disperse the
accumulation of inflammatory exudates, and initiate a
neurological sequence of events that would "close the
pain gait."
In the
final conclusion, the outcomes of the clinical trials
noted speak for themselves. |
