Scoliosis: The Spine Curves
by Louise Fenner
The young girl's spine was not
growing straight. In her shoulder area it curved to the right. In her lower back it curved
to the left. Instead of forming a straight line from neck to hips, the spine was taking on
the contours of a top-heavy letter S.
The doctor's diagnosis was
scoliosisan abnormal curvature of the spine that usually shows up during
adolescence. In most people the curvature is so mild that no treatment is needed. In her
case, however, the spine would continue to grow in a curve unless it could be coaxed along
a straighter path.
At 13, the girl was fitted with
a body brace that she would wear almost constantly for the next four years. She kept it on
22 hours of every day, tapering off only in the last year. By the time she reached 17 her
spine had stopped growing, the susceptibility to curvature had passed, and the brace could
be abandoned. It had been a difficult time, but the alternatives would have been
worsesurgery or, if untreated, a possible deformity and a lifetime of pain and other
Scoliosis is more common than
people may realize. It generally appears between the ages of 10 and 15, when a child's
spine is growing rapidly, and it affects 5 to 10 percent of all adolescents to some
degree. Very mild scoliosis occurs at the same rate in both sexes, but adolescent girls
are seven to nine times more likely to develop clinically detectable spinal curvature that
requires treatment. The reason for this is not known.
Everyone's spine has normal
curves that produce a slight rounding of the shoulder area and an inward curve of the
lower back, but in scoliosis the spine also curves laterally (sideways). It may resemble a
letter "S" or a long letter "C," depending on the number and types of
curves involved. The curvature described above is the most common type.
Another problem in scoliosis is
that as the spine grows, it gradually rotates (twists) on its own axis. The rotation
slowly pulls the rib cage around so that, in the back, one side of the rib cage becomes
higher and sticks out farther than the other. Furthermore, the ribs on the inward
(concave) side of the spinal curve are gathered together, while those on the outward
(convex) side are spread apart. This distortion of the rib cage can restrict the lungs,
causing breathing problems and possibly heart disease in later years.
Progressive scoliosis may
produce a cosmetic deformity and incapacitating back pain during adult life. Research has
shown that, on the average, adults with advanced (untreated) scoliosis tend to retire
earlier and die younger than the general population.
Most adolescent scoliosis is
"idiopathic," which means the causes are unknown. It is also a mystery why some
curves increase rapidly while most remain stable. A tendency toward scoliosis can be
inherited, and the disorder frequently runs in families. If one child is diagnosed, all
other growing children in the family should be examined. A few special cases of scoliosis
can be traced to neurological disorders such as polio, spinal cord injuries, cerebral
palsy and muscular dystrophy.
It is important that scoliosis
be identified as early as possible, since prompt treatment of progressing curves provides
the best chance of slowing or halting a progressive curvature. The most common treatment
is a body brace worn until the child reaches physical maturity and bone growth has
stopped, at about age 16 or 17. As an alternative, some physicians are using a new
technique that employs an electrical muscle stimulator. If the curvature continues to
increase despite these efforts, corrective surgery is called for.
Many states have established
school screening programs to monitor students around the ages of 10 to 15 for scoliosis.
In addition, parents may notice signs, particularly when the child is wearing underwear or
a bathing suit.
An adolescent with a spinal
curvature may appear to lean or list to one side, and even when standing as straight as
possible, his or her spine is still not "straight." A shoulder blade may be
prominent on one side, with one shoulder higher than the other. One hip can also appear
higher or be more prominent. From the back, the rib cage may appear to stick out or form a
hump on one side of the spine (usually the right side). When the arms are hanging loosely
at the sides, there may be more space between the arm and body on one side. Other clues
are repeated tilting of the head to one side, uneven hems and waistbands, uneven bra
straps, or one pant leg hem riding higher than the other.
An easy test for
scoliosisdone in school screening programsis to have the adolescent bend
forward from the waist. This makes both the sideways curve of the spine, plus any rib
protrusions, more visible. It helps differentiate scoliosis from poor posture, which can
be corrected merely by straightening up. With the child bending forward and touching their
knees, the rib humps on both sides of their backbone should be even and if one is more
than 1/4 inch higher than the other, call the doctor.
If scoliosis is suspected in a
growing patient, X-rays are usually taken to determine the type and extent of curvature.
In mild scoliosisa curve that measures 20 degrees or less and does not
progressregular observation by a physician may be all that is required. Most
adolescents with scoliosis fit into this category.
However, adolescents with spinal
curvatures of approximately 20 to 40 degrees are usually candidates for a body brace.
Studies have shown that the greater the curve, the more likely and the more rapidly it
will progress. The main function of a brace in scoliosis therapy is to guide the spine
while it is still growing. Most braces must be worn day and night for several years until
maturity (depending on the age of the patient), with one or two hours off daily for
exercise and bathing. Patients are encouraged to participate in virtually all physical
activities except competitive contact sports.
A brace is preventive medicine.
It will usually keep an existing curve from worsening and may help reduce it to some
extent, thus avoiding the need for surgery. Some braces are more cumbersome than others,
but the choice is based on the type of curvature being treated. For instance, the first
successful brace for scoliosis was the "Milwaukee" brace, introduced in 1945 and
still used today. It has a leather or plastic pelvic girdle, straps, and a ring that
circles the patient's neck to hold the support bars of the brace in position. However,
some newer types of braces made from molded plastic are less obtrusive because they hug
the torso beneath the underarm and can be concealed by normal clothing. These appear to be
effective with moderate spinal curvatures involving the lower thoracic and lumbar portions
of the spine.
Instead of wearing a brace
virtually 24 hours a day, some patients with moderate scoliosis are spending their nights
wired to an electrical muscle stimulator. This form of therapy for scoliosis became
available in 1983 following approval by the Food and Drug Administration. The electrical
muscle stimulator causes muscles near the spine to contract several times a minute. These
muscles, located on the outer or convex side of the spinal curve, provide a counteracting
force against other muscles that are pulling the spine out of line.
An electrical muscle stimulator
is used only at night while the patient sleeps. Like the more widely used brace, it must
be continued until the patient reaches bone maturity. FDA is requiring manufacturers of
electrical muscle stimulators to conduct follow-up studies of some patients to assess
long-term safety and effectiveness.
When a spinal curvature measures
40 to 45 degrees or more, surgery is usually required to prevent future health problems
and to correct any spinal deformity. Some curvatures may not be detected until they become
this severe; in other cases, a moderate curve continues to progress despite bracing or
other treatment. In addition to adolescent patients, a growing number of adults who have
severe curvatures are undergoing surgery to help relieve back pain and improve their
The most common surgical
procedure involves attachment of a thin stainless steel rod to straighten the spine, along
with fusion to hold the spine in a corrected position. The rodcalled a Harrington
rod after its inventoris attached to the exposed spine with hooks. One or more rods
may be used. Then fusion is effected by grafting small strips of bone, usually taken from
the back of the pelvis, over the affected vertebrae (sections of the spinal column). As
this heals, the fused section of spine becomes solid in a straightened position while the
rest of the spine stays flexible.
Other types of instruments may
be used instead of Harrington rods, depending on the patient's needs. Since problems
rarely result from permanent implantation of these instruments in the back, they are
removed at a later date only if necessary.
Generally, the patient must wear
a body cast around the ribs and pelvis for about six months after surgery, succeeded by a
brace worn for another three months. Once the spine is completely healed, a brace is no
longer needed. The patient is left with few limitations on his or her physical activity.
Scoliosis surgery, and the
subsequent recovery period, can be traumatic. It carries certain risks, as does any major
surgical procedure. Early detection and preventive treatment are obviously preferable.
Unfortunately, scoliosis is painless in its beginning stages and parents may not be aware
their child has a spinal problem until it has progressed to a significant curvature.
School screening programs often
pick up scoliosis cases that parents miss, and they can catch them early enough for
nonsurgical treatment to be successful. The screening programs in the United States and
Sweden have been so successful that there has been a significant reduction in the number
of children who required surgery recently for "idiopathic" scoliosis, according
to the Scoliosis Research Society, an association of physicians and scientists.
"Their curves have been detected early and have been managed successfully by
An FDA study ascertained that
some or all school districts in 18 states and the District of Columbia have mandatory
school screening programs that generally cover grades 5 through 9. In addition, more than
20 of the remaining states have voluntary scoliosis screening programs at the state,
county or local level.
"Screening programs have
dramatically reduced both the number and complexity of surgical procedures that are
performed for scoliosis," notes the American Academy of Orthopedic Surgeons.
"The real benefit of school screening programs for scoliosis, of course, can be
expressed in more human terms: the increase in psychological and physical well-being for
the children who do not progress to spinal deformity."
The growing emphasis on school
screening for scoliosis has probably led to an increase in the number of X-ray
examinations of the spine. After an initial physical examination, suspected cases are
generally referred to a health practitioner to confirm the diagnosis and to evaluate the
condition. Many children with mild curvatures who do not require treatment are
periodically monitored using X-rays to ensure that curvatures are not increasing.
Scoliosis patients are usually examined at least once a year and some as often as every
three or six months. One or more X-rays may be needed each time.
Health professionals are
becoming increasingly aware of the need to minimize radiation exposure during these X-ray
examinations, especially for girls. Past studies indicate that developing breast tissue is
particularly sensitive to the effects of radiation and that repeated exposure of the
breast during adolescence can increase a woman's risk of breast cancer in later life.
Fortunately, there are ways to
significantly reduce radiation exposure of the breast without compromising the quality of
the X-ray picture. These include the use of compensating filters, fast screen/film
combinations, and breast shields. Each of these techniques by itself can lower radiation
exposure markedly. When they are used together, the exposure reduction is even greater.
This filter is made of aluminum,
stainless steel, or transparent lead acrylic. It fits onto the X-ray tube by means of
magnets, special holders, or slots. The filter absorbs much of the X-ray beam directed to
the chest area, improves the X-ray image and, most importantly, reduces breast tissue
exposure by two to five times.
Fast Screen/Film Combinations
The "faster" or more
sensitive the film and intensifying screen used, the lower the radiation exposure of the
patient. A particular type of fast screen/film combination, called "rare-earth,"
is frequently used in scoliosis X-rays because it requires less radiation exposure without
significantly affecting image quality. This technique reduces breast tissue exposure from
two to six times.
There are two types of shields
that can be used to protect the breast during an X-ray examination. Contact shields are
vests or stole-like garments with lead inserts that are worn by the patient to cover the
breast area. Shadow shields are adjustable metal plates attached to the X-ray machine and
cast a "shadow" over the breast area. Breast shielding reduces radiation
exposure to the breast tissue by three to 10 times. Another method of breast shielding is
to turn the patient around so that she faces away from the X-ray machine. The body then
acts as a shield for the breast tissue.
If your child needs an X-ray
examination for scoliosis, remember the importance of radiation exposure reduction.
Although there is less cause for concern about breast cancer when the patient is a boy
(and thus no need for a special breast shield), it makes good sense to keep radiation
exposure to a minimum for all patients.
Louise Fenner is a member of
FDA's publications staff.
DEPARTMENT OF HEALTH AND HUMAN
HHS Publication No. (FDA) 85-4198