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 scoliosis—an 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 worse—surgery or, if untreated, a possible deformity and a lifetime of pain and other health problems.

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 scoliosis—done in school screening programs—is 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 scoliosis—a curve that measures 20 degrees or less and does not progress—regular 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 appearance.

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 rod—called a Harrington rod after its inventor—is 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 appropriate bracing."

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."

Scoliosis X-Rays

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.

Compensating Filter

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.

Breast Shielding

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.

Source:

DEPARTMENT OF HEALTH AND HUMAN SERVICES
HHS Publication No. (FDA) 85-4198
September 1984