Scoliosis means abnormal curvature of the spine greater than 10 degrees, as measured on an X-ray. Anything less than 10 degrees is considered normal variation in a normal individual. The curvature takes place in three dimensions.
Normally, the spine is straight when looking at a person from the front or back. When looking at a person from the side, the spine is curved. There is a gentle bending forward of the spine in the chest and a bending backward, called lordosis, between the chest and the pelvis.
In scoliosis, the spine appears S-shaped when looking at the front or back. When looking at the side, the normally curved spine typically straightens out. In addition, the spine twists on its axis, pushing the ribs and flanks backward and forward to produce a prominence, or hump.
Forms of scoliosis
Scoliosis may be divided into five principal types:
- Idiopathic scoliosis. This is the most common form of scoliosis. The term idiopathic means "the cause is unknown," and affected children are otherwise healthy and normal. The bones of the spine show no abnormality on X-rays or when looking at them directly in the operating room. While the overall incidence is equal in girls and boys, progressive or severe idiopathic scoliosis is about six to seven times more common in girls than in boys.
- Congenital scoliosis. Congenital scoliosis means the child was born with the condition, and it is caused by an abnormality of one or more vertebrae. The vertebrae don't form properly, which can be seen on X-rays and when looking at them directly in the operating room.
- Neuromuscular scoliosis. This is scoliosis that occurs in children who have a disease of the nervous system, such as cerebral palsy.
- Syndromic scoliosis. This type of scoliosis occurs in children with a syndrome, such as Marfan syndrome, or one of the skeletal dysplasias such as achondroplasia.
- Postural scoliosis. Also known as "hysterical scoliosis," postural scoliosis may be a result of pain, as the child tilts sideways to alleviate the pain. It can be reversed by relieving the pain or by having the child lie flat. X-rays don't show any abnormality of the vertebrae.
Signs & symptoms
Progressive, severe scoliosis can produce three major problems:
- If the part of the spine in the chest, called the thoracic spine, curves more than 90 percent, chest volume can be reduced so the heart and lung function are affected. The heart may have to pump harder, or your child may have difficulty breathing.
- Severe curvature of the lower half of the spine that connects the chest with the pelvis, known as the lumbar spine, may push the contents of the abdomen against the chest and interfere with heart and lung function. Curvature of the lumbar spine may also alter sitting balance and posture.
- Severe curvature of the thoracic or lumbar spine, or both, becomes visible. The tilting and twisting back, shoulders and pelvis may become unacceptable to your child. The most common scenario for idiopathic scoliosis – scoliosis with unknown cause – is in girls around puberty when body image and self-esteem are developing. The condition can pose psychological and emotional challenges.
Idiopathic scoliosis usually isn't painful. About 30 percent of patients with scoliosis have back pain, which is the same percentage found in children without scoliosis. There are certain exceptions in which an associated disease of the central nervous system, such as a fluid collection in the spinal cord, may produce pain as well as scoliosis.
Scoliosis can be diagnosed with a physical examination by a school nurse, pediatrician or orthopedic surgeon. The principal sign is asymmetry of the back, as the spine bends sideways and twists. Most commonly, this is detected by noticing a hump on the ribs or flank, between the ribs and hip, after asking the child to bend forward. The tilt produced in the back can be measured in degrees by a level; seven degrees or more is considered significant for scoliosis.
Other signs of scoliosis include elevation of one shoulder compared with the other, tilting of the pelvis – which may make one leg appear shorter than the other – and a difference in the contours of the flanks.
The next step after the physical examination is an X-ray of the spine.
Certain types of scoliosis are associated with other diseases, such as kidney disease. If a child with scoliosis is suspected of having an underlying disease, other tests may be necessary. Symptoms of possible underlying disease include significant pain, pigmented markings or a hairy patch on the skin or a deformity of the foot. Tests for underlying disease may include an ultrasound to look for kidney disease and a magnetic resonance imaging (MRI) study to look for an abnormality of the nervous system.
There's no clear evidence that untreated scoliosis, or scoliosis treated with bracing or spinal fusion, will increase the risk of back pain or arthritis in the long term.
The younger a child, or the more she or he has to grow, the greater the risk of scoliosis progressing. After puberty, curves less than 50 degrees are not likely to get worse. For this reason, the ultimate goal of scoliosis management is to keep curves under 50 degrees until your child has matured.
Children with curves less than 50 degrees typically grow up into adults with no significant problems related to scoliosis.
Scoliosis treatment is based on the degree of curvature of the spine, viewed from the front or back by X-ray. The following are general guidelines for treatment.
Less than 10 degrees
This is not scoliosis. Scoliosis is defined as spinal curvature greater than 10 degrees. Curvature under 10 degrees is considered a normal variation, just as there is a normal range for weight and height.
10 degrees to 30 degrees
In this range, scoliosis is observed for progression. The measurement error in reading X-rays is up to four degrees. This means that a difference of four degrees between office visits may not be real, but rather is a reflection of the inherent inaccuracies of measuring X-rays. Partly because of this, significant progression is defined as an increase in curvature of at least five degrees. The typical rate of progression is one degree per month, so it would take at least five months to see significant progression. As a result, the child is seen every six months for follow-up, which includes both physical and X-ray examinations.
30 degrees to 50 degrees
In this range, bracing is the standard of care in the United States. The scoliosis brace is known as a TLSO, which stands for thoraco-lumbar spinal orthotic. The idea behind bracing is to stop or slow progression of the curve so that it stays under 50 degrees. An X-ray of a brace shows that the brace can straighten the spine, but the spine will return to its original curvature when the brace is removed. The two principal types used are the Milwaukee brace, developed by Dr. Walter Blount of Milwaukee, and the Boston brace, developed by Dr. John Hall of Boston.
The brace is worn more than 20 hours per day. Time is allowed out of the brace for hygiene and for sports. Part-time bracing doesn't work as well and may not work at all. The child is weaned into the custom-made brace gradually over a two-week period. This allows the child to adjust and prevents significant skin irritation from the brace. After two weeks of full-time wear, or approximately four weeks after initial fitting of the brace, the child is seen in the office for X-rays in the brace.
Successful bracing reduces the curve by half or better as determined by X-rays. At later visits, X-rays are taken out of the brace, which is removed the night before to allow full relaxation of the spine and a more realistic measure of the degree of curvature. Brace treatment successfully stops curve progression in about 80 percent of children.
More than 50 degrees
Beyond 50 degrees, the spine loses its ability to compensate and progression becomes inevitable even after the child is mature. The only way to stop progression at this stage is a surgery called spinal fusion. Think of the vertebrae as beads on a string. The spine bends between the vertebrae as a string bends between the beads, causing the beads to move. The way to stop the beads from moving is to stick them together. Spinal fusion surgery joins the vertebrae.
More treatment info
Spinal fusion surgery
Our pediatric orthopedic surgeons perform spinal fusion surgery, which corrects severe scoliosis by connecting spinal bones.Learn more
Vertebral body tethering
This surgery for scoliosis uses your child's own growth to straighten the spine and may offer advantages over traditional approaches.Learn more
UCSF Benioff Children's Hospitals medical specialists have reviewed this information. It is for educational purposes only and is not intended to replace the advice of your child's doctor or other health care provider. We encourage you to discuss any questions or concerns you may have with your child's provider.
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