Herniated Nucleus Pulposus
- HERNIATED DISC -
A herniated disc is a fragment of the disc nucleus which is pushed out
of the outer disc margin, into the spinal canal through a tear or
"rupture." In the herniated disc's new position, it presses on spinal
nerves, producing pain down the accompanying leg. This produces a sharp,
severe pain down the entire leg and into the foot. The spinal canal has
limited space which is inadequate for the spinal nerve and the displaced
herniated disc fragment.
The compression and subsequent inflammation is directly responsible for
the pain one feels down the leg, termed "sciatica." The direct
compression of the nerve may produce weakness in the leg or foot in a
specific patter, depending upon which spinal nerve is compressed.
A herniated disc is a definite displaced fragment of nucleus pushed
out through a tear in the outer layer of the disc (annulus). For a disc
to become herniated, it typically is in an early stage of degeneration.
In this situation there is a portion of the
annulus that has isolated itself from the rest of the disc and all or
part of its displaced will out into the canal. This situation is the one
that responds best surgery. It may not respond to conservative therapy,
including manipulation and even chemonucleolysis.
Typical Pain and Findings
Typically, a herniated disc is preceded by an episode of low back pain
or a long history of intermittent episodes of low back pain. However,
when the nucleus actually herniates out through the annulus and
compresses the spinal nerve, then the pain typically changes from back
pain to sciatica. Sciatica is sharp pain which radiates from the low
back area down through the leg, into the foot in a characteristic
pattern, depending upon the spinal nerve affected. This pain often is
described as sharp, electric shock-like, sever with standing, walking or
sitting. The pain is frequently relieved by lying down or utilizing a
lumbar support chair or insert.
There also may be resulting leg muscle weakness from a compromise of the
spinal nerve affected. Most commonly, the back pain has resolved by the
time sciatica develops, or there is minimal back pain compared to the
severe leg pain. The location of the leg pain is usually so specific
that the doctor can indentify the disc level which is herniated. In
addition to leg muscle weakness, there may also be knee or ankle reflex
What Diagnostic Tests are Used for Evaluations
X-rays of the low back area are obtained to search for unusual causes of
leg pain, i.e. tumors, infections, fractures, etc. An MRI of the lumbar
spine area is obtained, as this will demonstrate the degree of disc
degeneration at the herniated level, in addition to the condition of
other lumbar discs in the low back.
A quality MRI will accurately demonstrate the size of the spinal canal
and most other medically significant factors. A nerve test may be
indicated to demonstrate whether there is ongoing nerve damage, or if
the nerves are in a state of healing a past insult, or whether there is
another site of nerve compression.
The initial treatment for a herniated disc is usually conservative, i.e.
nonoperative. One usually begins with resting the low back area,
maintaining a comfortable posture and painless activity level for a few
days to several weeks. This in in order to allow the spinal nerve
inflammation to quiet down and resolve.
A herniated disc is frequently aided by non-steroidal anti-inflammatory
medication such as Motrin, Voltaren, Naprosyn, Lodine, Feldene, Clinoril,
Tolectin, Dolobid, Advil or Nuprin. An epidural steroid injection may be
performed utilizing a spinal needle under x-ray guidance to direct the
medication to the exact level of the disc herniation.
Physical therapy may be beneficial, under the direction of a physical
therapist. The therapist will perform an in-depth evaluation; this
information, combined with a physician's diagnosis, will dictate a
treatment based on successful physical therapy treatment modalities
which have proven beneficial for herniated disc patients. These may
include traction, ultrasound, electrical muscle stimulation, etc., to
relax the muscles which are in spasm and secondarily inflamed from the
compressed spinal nerve. Pain medication and muscle relaxing medications
may also be beneficial to help physical therapy or other conservative,
non-operative treatment to relieve the pain while the spinal nerve root
inflammation resolves and the body heals itself. If these conservative
treatments are not successful and the pain is still severe or muscle
weakness is increasing, then surgery is necessary. Surgery may be in the
form of a percutaneous discectomy if the disc herniation is small and
not a completely extruded disc fragment.
If the herniation is large, or is a "free fragment" as described above,
then a microlaminotomy with disc excision is necessary. A micro-laminotomy
requires one to two days of hospitalization after the surgery for the
wound to heal and postoperative physical therapy to begin. The sciatic
pain down the leg should be resolved immediately after the surgery.
However, there will be some discomfort in the low back area where the
operation is performed, lasting several days to a couple of weeks. This
is controlled with pain medication.
A person who has sustained one disc herniation is statistically at
increased risk for experiencing another. There is an approximate 5% rate
of recurrent disc herniation at the same level, and a lesser incidence
of new disc herniation at another level. Factors involved may be weight
related level of physical conditioning, work or behavioral habits. Since
these factors are typically the same after surgery, there is an
increased risk of herniated disc in this group, over the general
However, the good news is that the majority of disc herniations (90%) do
not require surgery, and will resolve with conservative, nonoperative
treatment, without significant long-term sequelae. Unfortunately,
approximately 5% of patients with herniated, degenerated discs will go
on to experience symptomatic or severe and incapacitating low back pain
which significantly affects their life activities and work. This
unfortunate result is not always specifically the result of surgery. The
causes of this unremitting pain are not always clear or agreed on, and
my be from several sources. When this occurs, the prognosis is poor for
returning to normal life activities regardless of age.
After a successful laminotomy and discectomy, 80-85% of patients do
extremely well and are able to return to their normal job in
approximately six weeks time. There may be small permanent patches of
numbness in the involved leg which, fortunately, are not disabling.
Flare-ups or exacerbations of less severe and less significant sciatic
type pain may develop in the future (usually on an infrequent basis).
Our advice to those who have herniated disc disease is to become
knowledgeable in back school lifting techniques and activity
modifications from your physical therapist. Making your back strong
through exercises performed for approximately 30 minutes daily will
restore normal flexibility in the lumbar spine region, as well as
strengthen muscles which can resist strain and repeat injury. Always
avoid heavy lifting, especially in association with twisting of the
lumbar spine. Protect your back for at least nine months to a year after
sustaining the herniated disc.
Feel free to consult your physical therapist for more specific
recommendations regarding postoperative or post-herniated disc lumbar
spine reconditioning and maintaining a well-conditioned spine.