SIMPLE PELVIC TRACTION GIVES INCONSISTENT RELIEF
TO
HERNIATED LUMBAR DISC SUFFERERS.
EDWARD L. EYERMAN, MD
Journal of Neuroimaging June 1998
A new decompression table system applying fifteen 60 second
tractions of just over one half body weight in twenty one-half
hour sessions was reported to give good or excellent relief
of sciatic and back pain in 86% of 14 patients with herniated
discs and 75% of patients with facet joint arthrosis. (Shealy,
C.N.,Borgmeyer, V., AMJ. Pain Management 1997,7:63-65).
Herniated and degenerated discs can be shown at discography-discomanometry
to have elevated intradiscal pressures made even worse by
sitting and standing, thus preventing proper disc nutrition.
Therefore decompressing the over pressurized disc should allow
for healing and repair of disc prolapse, herniation and annulus
tears. Serial MRI of 20 patients treated with the decompression
table shows in our study up to 90% reduction of subligamentous
nucleus herniation in 10 of 14. Some rehydration occurs detected
by T2 and proton density signal increase. Torn annulus repair
is seen in all. Transligamentous ruptures show lesser repair.
Facet arthrosis can be shown to improve chiefly by pain relief.
Follow up studies for permanency or relapses are in progress.
The DRS Mechanical Decompression Distraction System was described
by Shealy and Borgmeyer (1) to give relief of lumbar herniated
disc and facet joint arthrosis superior by 50% to conventional
pelvic traction. Twenty DRS treatments produced on midsagittal
MRI a 50% reduction in one case, and a 7mm distraction of
1.5 on SI was shown on lateral x-ray. (2) Clinical improvement
in 75 to 85% of subjects was reported. Does clinical betterment
correlate directly to improvement in MRI image and can MRI
shed any light on the mechanism of improvement?
That the abnormal disc has an elevated pressure can be appreciated
at discogram. It is postulated that this elevated pressure
interferes both with diffusion of nutrients from surrounding
vessels into the nucleus and with adequate patching or repair
of the tom annulus. Nachemson's group has emphasized lowering
intradiscal pressure for 30 years. (3) & (4) Neurosurgeons
Rainon and Martin (5) at operation on a similar decompression
table measured in an L45 herniated disc a lowering of intradiscal
pressure from 30 to 50 mm above the normal 90 to 100 mmHg
into the negative range of minus 100 to 150 mmHg during 90
to 95 LB traction. Will such negative pressures heal the annulus,
rehydrate the nucleus?
The aim of the present study was to do before and after MRI
to correlate clinical improvement with any MM evidence of
disc repair in annulus, nucleus, facet joint or foramen as
a result of DRS treatment. A course of 20 DRS Lumbar De-compression
treatments were given in 4 to 5 weeks to 18 patients, and
a double course of 40 in 10 weeks to 2 more. Pull of distraction
was adjusted to one half-body weight plus IO lbs. Each session
consisted of 20 repetitions in 30 minutes of full distraction
for 60 seconds and 30 seconds of relaxation to 50 lbs. Distraction
angle on pelvic harness was varied from 10% for L5-S I to
20 to 25% for L4-5 herniations and above.
Subjects comprised 12 males and 8 females from age 26 to
74. Radiculopathy in 14 patients was from herniated discs
of varying sizes. (L5-S I level in 6, L4-5 in 6, and 1 each
at L3-4 and L2-3). Radiculopathy without disc herniation was
present in 6 patients from foraminal stenosis facet arthropathy
and lateral spinal stenosis. EMGs confirmed radiculopathy
in all. MRI's before and after were obtained on high and mid
field units. Clinical status was assessed before, during,
and after treatment with standard analog pain rating scale
of 0- I0 and a neuro exam.
Range of motion for spinal mobility (initially impaired in
all), myotomal weakness reflex and dermatomal sensory loss
were tested.
A) MRI OUTCOMES
- Disc Herniation: 10 of 14 improved significantly, some
globally, some at least local at the site of the nerve root
compression. Measured improvement in local or general disc
herniation size varied in range of 0% in 2 patients, 20% in
4 patients, 30 to 50% in 4 patients and a remarkable 90 %
in 2 patients who had the number of treatments at 40 sessions
in 8 weeks.
- Facet joint arthropathy and foraminal compression
cases showed no demonstrable change save 2 cases with slight
increase in height but not in hydration.
B) CLINICAL OUTCOMES
Irrespective of MRI status all but 3 patients had very significant
pain relief, complete relief of weakness when present, and
of immobility and of all numbness (save in 1 patient with
herniation and 2 with foraminal stenosis without herniation).
With disc herniation, 10 patients of 14 had 10 to 90% improvement
in pain and disability. Two had 40 to 50%, one had only 20%
with foraminal syndrome without herniation, 4 had 70 to 100
% improvement, one had 40 to 50 %, one with severe spinal
stenosis had only 25% and was sent for surgery. Degree of
clinical improvement roughly followed MRI changes but not
totally with full correlation.
Improvement from DRS treatment clinical outcome of radiculopathy
whether from disc herniation or foraminal syndromes is more
impressive than most improvement shown consistently by MRI,
at least with today's techniques and short time of follow-up.
Relief of pain and disability by reduction of disc size is
easy to argue in a small majority of this series. A few patients
have dramatic anatomic improvement. The others with minimal
or no significant MRI improvements are harder to explain.
Also, many patients improved very early in treatment, probably
before MRI change could be seen.
Nutrient diffusion increase and tom annulus healing resulting
from lowering intradiscal pressures are likely causes of clinical
improvement when MRI anatomy is not much altered by distraction.
Leaking of important sulfates and carboxylates from the nucleus
and posterior annulus have been shown in recent studies. (6)
and (7) lowering of intradiscal pressure by DRS treatment
likely can start to reverse these processes by allowing fibroblast
repair of the annulus outer layers and some nutrition to the
nucleus. Also penetration of nerves into inner annulus and
nucleus of degenerated prolapsed discs has been recently demonstrated
and could play a role in pain production. (8) Mechanical intradiscal
pressure relief may help this feature as well as giving structural
stability.
- DRS distraction treatments afforded good or excellent
relief of pain and disability whether from herniated disc
or foraminal or lateral spinal stenosis.
- MRI showed imperfect correlation with degree of clinical
improvement but 10 to 90% reduction in disc herniation size
could be seen at least at the critical point of nerve root
impingement in 10 of 14 patients.
- Two patients with extended courses of treatment showed
90% disc reduction and one of these had early rehydration
of the degenerated disc at L4-5. An "empty pouch"
sign on MRI at the site of previous herniation was seen in
these 2 patients.
- Foraminal and lateral spinal or facet arthrosis cases
causing radiculopathy without herniation also improved but
without MRI change.
- Annulus healing or patching in the herniated disc can
be shown by MRI and is postulated to be a primary factor in
clinical and MRI improvement.
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