From time to time, the National Scoliosis Foundation receives letters from parents about kyphosis. To find out more about this spinal deformity, our Medical Update editor, Nancy Schommer, interviewed Dr. Howard King, Clinical Associate Professor of Orthopaedic surgery, University of Washington, and Northwest Spine and Pediatric Orthopaedic Surgeons Seattle, Washington. What follows are excerpts from that interview.
Q: Dr. King, how do you define the spinal deformity known as
kyphosis?
A: Let me begin by saying that everyone has a little bit of round
back (kyphosis) and a little bit of swayback (lordosis). As a spinal
deformity, however, kyphosis is defined as an abnormal increase
in the sagittal plane curvature. If you look at a person from the
side and see more " roundback " than is considered normal,
it's possible that the person has some type of kyphosis.
Q: What are the measurements of normal vs. abnormal kyphosis?
A: The degree of normal kyphosis is usually considered to be between
20 and 40 degrees. Once the curvature approaches 45 to 50 degrees
or more, we'd consider that abnormal.
Q: Where along the spine does abnormal kyphosis occur?
A: It can occur anywhere-in the cervical area, the thoracic area,
or the lumbar area, but most often we see it in the thoracic or
chest area which is naturally rounded to begin with.
Q: Is kyphosis as common as scoliosis?
A: Not at all. The incidence of scoliosis is roughly 2 in 100, whereas
the incidence of kyphosis is approximately 1 in 1,000.
Q: Tell us about a variation on normal kyphotic development
that you see in your practice.
A: Quite often, we see adolescents with "postural roundback,"
which is confused with abnormal kyphosis. 'I'm sure your readers
have seen teenagers slouching or hunched over. They have poor posture,
but no deformity; when you ask them to stand straight, they're able
to straighten up, and if you take an x-ray, you see that their spines
are perfectly normal. Sometimes, postural exercises can help, but
eventually, most postural roundbacks straighten by themselves as
the individual matures.
Q: What about some of the abnormal cases of kyphosis that you're
currently seeing?
A: One of them is called Scheuermann's Disease, a deformity which
can be differentiated from postural roundback by clinical examination
and x-rays. Whereas the postural roundback patient generally has
a flexible spine and normal vertebral development, a patient with
Scheuermann's will have structural problems, including vertebral
wedging (instead of being rectangular, the affected vertebrae are
trapezoid-shaped); disk space narrowing; and irregularity of the
end plates of the vertebrae. As a result of these and other problems,
patients with Scheuermann's cannot stand up straight.
Q: Is pain associated with Scheuermann's Disease?
A: A fair number of youngsters come in with pain. We presume that
the pain is caused by micro-fractures of those wedged vertebrae.
Q: Do scientists know what causes Scheuermann's?
A: The etiology is unknown, but studies suggest a variety of etiologies
that include mechanical, familial, hereditary, developmental, traumatic
and metabolic theories.
Q: What are your objectives for treatment of Scheuermann's?
A: Treatment is usually based on these objectives: (1) Relief of
pain; (2) avoidance of recurring pain; (3) improvement in deformity;
and (4) maintenance of that improvement.
Q: Tell us about the various treatments for Scheuermann's.
A: In children with pain and deformities between 60 and 80 degrees,
Milwaukee-type bracing can be helpful. Bracing tends to work better
on curves that are under 80 degrees-in many cases, up to 50% correction
can be obtained. Surgical treatment is rarely indicated, although
persistent pain and a progressive deformity are reasonable indications
for surgery. When surgery is indicated, we usually combine an anterior
and posterior approach and do both procedures on the same. The type
of hardware used would determine whether or not the patient would
need to wear a post-surgical brace.
Q: What other types of abnormal kyphosis are you seeing?
A: Congenital kyphosis is usually caused by some structural defect-for
example, the anterior (front) part of the spine may not have formed
properly. The deformity may be severe, and neurological problems
may result. Early posterior fusion can be done in children under
five with a kyphosis of less than 50 degrees. If the patient is
older than five, or has a curve over 50 degrees, we would perform
a combined anterior and posterior surgery. We usually recommend
that patients with congenital kyphosis have a pre-operative MRI
scan that would help us detect spinal cord problems.
We're also seeing patients with "post laminectomy kyphosis,"
a condition sometimes caused when surgery is per- formed to remove
a tumor of the spinal cord. In surgery, figaments and other structures
are removed, which causes the loss of one's posterior 'tether'-think
of it as a guy wire that keeps your spine upright. Without that
tether, the spine starts to bend and kyphosis can result. We can
reconstruct the spine with surgical treatment, but we're trying
to avoid the problem in the first place by educating neurosurgeons
and oncologist and rehabilitation people to watch for these deformities.
Q: We sometimes receive letters from individuals about "dowager's
hump," a deformity that causes the patient to be hunched over.
Is that a type of kyphosis, what causes it, and what can be done
about it?
A: Yes, we do consider this kyphosis. We're seeing it more and more
in senior citizens who develop osteoporosis (loss of bone density)
and as result, their spines start to collapse. These problems are
generally treated medically with calcium vitamin D and other medications.
Pain can on occasion be reduced by brace treatment. Surgery can
be performed in severe cases with collapse of the spinal column
and where neurologic compromise has occurred. Because the bone density
is decreased, this surgery is complex and the results are variable.
The best course of action is prevention. Young women need to be
on a regular exercise program, and should get at least 1,200 mgs.
of elemental calcium per day-either through diet or with supplements.
When women begin menopause, they should continue with an exercise
program, and be on appropriate hormone replacement therapy under
the supervision of their doctor. Cigarettes and caffeinated beverages
are best avoided.
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