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The WKNI is fortunate to have highly skilled and experienced neurosurgeons on staff to
perform spinal surgery for patients experiencing back pain. Along with cutting-edge
diagnostic tools, these physicians utilize the most highly sophisticated
surgical instrumentation and monitoring devices available in the
country. With the support of a superb surgical staff and skilled diagnosticians, the
treatment plan for each patient is assessed before, during and after surgery to assure
the best possible surgical outcome.
What causes back pain?
In general, most patients experience episodic back pain that is temporary and will heal
with time. The majority of low back pain is due to muscle strain and approximately 90% of
patients will feel relief within three months without the need for surgical intervention
(spine-health.com). However, patients who
experience severe pain or pain for longer than three months, or who have pain in their
arms or legs should seek medical attention to definitively pinpoint and treat the source
of the pain.
How is the cause of back pain determined?
There are several diagnostic techniques used to determine the root cause of back pain.
X-rays are the most common and inexpensive imaging technique. They are usually the first
step in achieving a complete diagnosis. Based on the results from the X-ray, a treatment
plan may be developed, or more extensive imaging techniques
may be used. These include: Computerized Tomography (CT) scans which take a cross-sectional
view of the spine and its bony components; CT with myelogram, which shows the bony structure
and the associated nerve roots; and Magnetic Resonance Imaging (MRI), which provides a
highly refined detailed picture of the entire anatomy of the spine.
Figure 1. Graphic of the whole spine showing the cervical, thoracic and lumbar sections.
Other diagnostic tools may also be used to assess the health of
the nerves present in the cervical (neck) or thoracic (chest) areas of the spine if damage
in these areas is suspected (Figure 1). Somatosensory evoked potentials (SSEP) may be recorded
to assess the speed at which the nerves are conducting electrical signals across the spinal
cord. If the cord is significantly pinched or adversely affected, the signals will travel
slower than normal. Electromyography (EMG) may also be done to assess the electrical activity
of the nerve root. EMGs can help to distinguish nerve degeneration from nerve root
compression.
What are the specific causes of back pain and when is
surgery indicated?
For patients with chronic lower back pain, there are several possible causes
(Figure 1, lumbar spine). These may include disc herniation, degenerative disc disease,
and isthmic spondylolisthesis in younger adults. In older adults, osteoarthritis, lumbar
spinal stenosis and degenerative spondylolisthesis may be indicated (see below).
For patients with upper back pain, causes may include disc herniation, cervical stenosis,
cervical degenerative disc disease and cervical osteoarthritis (see below) (Figure 1,
cervical spine).
Spinal trauma and tumors of the spine may also cause pain at any age.
After consultation with a neurosurgeon, it may be determined that the best course of
treatment to correct these conditions is through surgical intervention. Surgeons at the
WKNI offer several surgical procedures to address each of these conditions.
In general, surgeons can relieve the pain through "decompression surgery", in which the
piece of the offending disc or bone is removed; and/or through "fusion surgery", in which
portions of the bony spine are fused together to decrease or eliminate excessive movement
of the disc, thereby eliminating the source of pain. Some common conditions requiring
surgical intervention are discussed below:
- Disc herniation: Discs can herniate in any area of the spine and protrude
into the spinal canal where they press on the nerves radiating out from the canal
(Figures 2, 3). This can cause pain to radiate down the patient's leg, with the
possibility of accompanying numbness or weakness in the foot and ankle.
Figure 2. Graphic of a normal disc and surrounding structures.
Figure 3. Graphic of intervertebral disc with posterior herniation.
Surgical treatment: Surgeons can perform a laminectomy, in which a small portion
of the outer bone covering, or lamina, over the nerve root is removed. This can be done
with or without discectomy, in which the portion of the disc that is restricting the
nerve root is extracted. These two procedures provide more room for the nerve to heal,
thereby alleviating pain.
- Degenerative disc disease: Over time, discs in the spine naturally degenerate
but do not necessarily cause back pain. However, a patient can injure and weaken the
disc space in the region, many times as a result of a twisting injury (especially in the
lower back). Because the disc is weakened, there is excessive movement around the disc,
causing inflammation and irritation of the local area. The patient can then experience
chronic back pain.
Surgical treatment: If surgery is indicated, spinal fusion can be performed to
stabilize the area. First, bone is obtained, either from a cadaver (allograft bone),
or from the patient's own pelvis (autologous bone). The bone grafts provide "scaffolding"
to promote new bone growth. Autologous bone also provides a reservoir of new bone cells
along with serving as a supportive matrix. Other sources, such as demineralized bone
matrix, and other materials are also available.
The surgeon can fuse the disc area together by placing replacement bone either in front
of the spine (anterior interbody fusion) in the disc space, or along the back of the
spine (posterior interbody fusion), or both in front and in back, depending on the area
of the spine that is affected. The fusion of the spinal segment limits the motion around
the affected area, thereby decreasing or eliminating the pain.
In some cases, the surgeon may insert screws and rods into the pedicle region of the
spine around the affected disc. These pedicle screws and rods help to stabilize the
area and restrict movement so that the bone graft can heal. In the cervical area,
surgeons may apply a small plate to add stability to the area.
- Isthmic or degenerative spondylolisthesis: Spondylolisthesis means "slipped
vertebral body". In patients with this condition, a stress fracture or generalized
degeneration in one of the lower lumbar vertebra (L4 or L5) causes it to slip forward and
press onto, or dislocate over, another vertebra. (Figure 4). Pain can result from disc
degeneration as the disc tries to stabilize itself, or from the fracture itself, if
present.
Figure 4. Lateral radiograph showing spondylolysis; the dotted line shows the anterior displacement of vertebra L5 (spondylolisthesis).
Surgical Treatment: Surgeons may treat spondylolisthesis by performing a
laminectomy (bone removal) and spinal fusion (see degenerative disc disease, above).
- Lumbar Spinal Stenosis: Over time, the facet joints (located in the back
of the spine) may enlarge as they degenerate, and may press on the nerves as they exit
the spine (Figure 2).
Surgical Treatment: Surgeons may treat lumbar spinal stenosis by performing a
laminectomy, where bone is removed to give the nerves more room (see degenerative disc
disease, above.)
- Cervical foraminal stenosis: The cervical disc space may narrow over time,
even without disc herniation, as a result of enlargement of a joint into the spinal
canal (Figure 2).
Surgical Treatment: For cervical stenosis, the disc may be removed to allow
for more room for the nerve. The open space is then preserved through fusion of a
bone graft into the area.
- Osteoarthritis: The facet joints on the back of the spine are made up of
two bony processes with cartilage between them, all surrounded by a capsule which is
filled with fluid (Figure 2). The cartilage and fluid normally permit the joints to
move without much friction. In a patient with osteoarthritis, cartilage within the
joints breaks down, resulting in the creation of greater friction within the joint.
This leads to increased stiffness and back pain.
Surgical Treatment: It is possible to perform fusion surgery for osteoarthritis
to restrict movement in the painful joint. However, surgery is generally not recommended
since several verterbrae are usually affected and fusion of multiple levels of the spine
would be required.
Spine Health Related Links
Spine-Health.com
National Institute of Arthritis and Musculoskeletal and Skin Diseases
lowback-pain.com
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