Lumbar spinal stenosis
Facet joints tend to get larger as they degenerate.
This process is the body’s attempt to decrease
the stress per unit area across a degenerated
joint. Unfortunately, as the joint enlarges,
it can place pressure on the nerves as they exit
the spine (see Figure
1).
Standing upright further decreases the space
available for the nerve roots, and can block
the outflow of blood from around the nerve. Congested
blood then irritates the nerve and the pain travels
into the legs.
Generally, patients with spinal stenosis are
comfortable if they are sitting, but have more
pain down their legs when they walk and the pain
increases with more walking ("neurogenic
claudication"). Walking while leaning over
a supporting object (such as a walker or shopping
cart) can help ease the pain, and sitting down
will cause the pain to recede.
Treatment options
Options for conservative treatment for spinal
stenosis include activity modification and epidural
injections.
-
Activity modification. Since patients
are more comfortable when they are flexed
forward, they can concentrate their activity
in that position and exercise can include
stationary biking and using a cane or walker
for walking while flexed forward.
-
Epidurals. Approximately 50% of patients
will experience good relief after an epidural
injection, although the results tend to be
temporary. If the injection is helpful it
can be done up to three times annually. The
action of the injection is not clearly known,
but is probably a combination of the anti-inflammatory
effect of the steroid and a flushing effect
due to injecting a volume of fluid.
Spine surgery (an open decompression
or laminectomy) is the only way to change the
anatomy of the spine and give the nerves more
room. Decompressing the nerves by removing a
portion of the enlarged facet joint prevents
the nerve pinching when the patient stands up.
It is effective in approximately 80% of cases,
although over a 5-year period of time the results
tend to deteriorate. Part of this deterioration
is due to the progressive nature of osteoarthritis,
and part is due to the overall aging process.
It should be noted that lumbar spinal stenosis
rarely causes nerve damage, and surgery is almost
always elective. The results seem to be as good
if the surgery is done early or delayed, even
for years.
By: Peter
F. Ullrich, Jr., MD
September 8, 1999
Updated February 28, 2001 |
