Degenerative Disc Disease
Degeneration
of the disc occurs when the vertebral endplate tears from its connection to
the intervertebral disc. The disc itself has no blood supply and relies upon
osmosis of nutrients and Oxygen from the vertebral endplates above and below.
When there is an interruption from one of the endplates the disc begins to
show damage due to lack of nutrients and Oxygen. Gradually this process spreads
to other parts of the disc. In fact this may be a normal part of the way that
the spine degenerates with age, but often the more rapid degeneration caused
by abrupt injury results in a painful reaction. This may occur because of
loss of mechanical advantage causing pain in the outer third of the disc anulus
or it may occur because of an inflammatory response. Furthermore, weakening
of the inner disc wall may cause internal disc disruption or herniation. Additionally
pain may be provoked by loss of disc height causing compression of the nerve
root in the neuroforamen. Another consequence of loss of the normal architecture
of the disc and its relationship to the vertebrae is zygapophyseal joint pain
due to compression, hypertrophy or inflammation of these joints.
Discs can degenerate in the Cervical, Thoracic or Lumbar spine.
Clinically the most significant problems are Lumbar
Disc Degeneration and Cervical Disc Degeneration.
Painful
degenerative disc disease can be treated in a number of ways. Conservative
approaches may involve the use of physical therapy and/or pain medications,
including antiinflammatories, opioids and membrane stabilizers. Additionally
blocks to nerve roots and facet joints may be both therapeutic and diagnostic.
Discograms can help determine if internal
disc disruption is present. If it is a part of the clinical picture an IDET
(Intradiscal Electrothermal Therapy) approach can be taken. Some surgeons
even recommend using the epidurascope to visualize the torn anulus and repair
this, employing microsurgical techniques. Still the mainstay of surgical treatment
for the painful degenerative disc is that of spinal fusion surgery, which
may be done from the anterior approach, posterior approach or both, with and
without hardware placement.
Spondylolisthesis
can also occur with disc degeneration. Spondylolisthesis is the actual slipping
of a disc forward, backwards or to the side, due to weakening of the restraining
connective tissue. It can occur as a congenital abnormality or it can be the
result of degenerative disc disease. Spondylolisthesis is graded by degree
of severity. When this becomes severe enough, the patient suffers with a high
degree of spinal stenosis from the nerve being trapped by the slipping disc.
The condition must be halted and the nerve path cleared if it is not to become
worse. The only appropriate surgical approach is that of fusion, which can
be done as an anterior and posterior fusion with instrumentation or sometimes
by use of fixation with a transverse titanium cage.
Degenerative
Scoliosis can also be quite problematic. This occurs secondary to sideway
slippage of a degenerative spine and can be very extensive causing severe
pain, loss of nerve function and collapse of the spinal cord. Patients can
become severely disabled and pain is extremely high. Surgical interventions
are often necessary over several levels. Bracing can help with some palliation
and protection, but when this becomes severe, extensive multilevel fusions
with instrumentation may be the only solution to stemming the tide of runaway
spinal collapse.