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Degenerative
changes in the spine are often referred to those that
cause the loss of normal structure and/or function.
Degenerative Spondylolisthesis (DS) is a disorder that
causes the forward motion (slip) of one vertebral body
over the one below. The term Spondylolisthesis is formed
from two Greek words; spondylo meaning vertebra and
olisthesis meaning to slide on an incline. DS is most
common in the lumbar spine (L4-L5) and may cause low
back pain.
Symptoms
and Non-Operative Treatment
Typical
symptoms include low back pain, muscle spasms, thigh
or leg pain, and weakness. Interestingly, some patients
are asymptomatic and learn of the disorder following
spinal radiographs.
Low
back pain associated with DS is treated non-operatively.
During the acute pain phase, bedrest may be recommended
for a few days. Activities involving heavy lifting and
stooping are prohibited to prevent stress to the lumbar
spine.
Drug
Therapy
During
the acute phase of low back pain, drugs may be prescribed.
Some of these may include narcotics, acetaminophen,
anti-inflammatory agents, muscle relaxants, and anti-depressants.
Narcotics
are used on a short-term basis partially due to their
addiction potential. When low back pain is caused by
muscle spasm, a muscle relaxant may be prescribed. Muscles
relaxants are usually used no longer than one week and
have sedative effects. Depression can be a factor in
chronic low back pain. Anti-depressant drugs have analgesic
properties and may improve sleep.
Bracing and Physical Therapy
Other conservative non-operative treatment may include
a custom-made brace. A brace is designed to reduce the
loads (weight) to the lumbar spine. Physical therapy
may be added to the treatment plan. Forms of therapeutic
exercise including stretching may improve the flexibility
of the trunk muscles. Other non-aerobic exercises may
help to improve muscular endurance, coordination, strength,
and facilitate weight loss. Exercise also helps to combat
anxiety and depression.
Disease
Progression and Neurologic Deficit
Although degenerative spondylolisthesis may cause a
vertebra to slip forward, that does not always mean
the disorder is progressive. The vertebral segment may
be stable without any neurologic compromise. Surgery
becomes a consideration when the disorder causes neurologic
deficit, such as incontinence or the slip progresses.
Spinal fusion and instrumentation may become a consideration
if slippage exceeds three millimeters. These surgical
procedures stabilize the spinal column.
The
surgeon bases his/her decisions on the patient's medical
history, symptoms, radiographic findings, as well as
the degree and angle of the vertebral slip. Patients
who use tobacco or are obese are known to have lower
rates of success with fusion. Nicotine hampers the fusion
process and obesity places excessive weight on the lumbar
spine.
Spinal
Fusion and Instrumentation
Spinal fusion and instrumentation are combined. Spinal
fusion uses the patient's (preferred) own bone harvested
from the iliac crest (pelvis). Donor bone is an option.
Spinal instrumentation uses medically designed implants
such as screws and cages. The implant(s) holds the vertebral
segment secure facilitating fusion. Instrumentation
provides more rapid pain relief, recovery, and may eliminate
the need for bracing following surgery. Two surgical
procedures that utilize spinal fusion and instrumentation
are termed Anterior Lumbar Interbody Fusion (ALIF) and
Posterior Lumbar Interbody Fusion (PLIF). The difference
between the two procedures is the surgical approach
to treat the disorder (front or rear).
In Conclusion
Although aging adults can expect some degenerative processes
to occur in their spines, this certainly does not point
to a future facing disability. In general, spondylolisthesis
only affects a small percentage of the population. Overall,
most degenerative disorders of the spinal can be treated
non-surgically with good outcomes.
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