What is scoliosis?
Scoliosis is a condition that causes your child’s spine to curve sideways and twist. This curve can lead to changes in their shoulders, ribcage, pelvis, waist, and the overall shape of their back.
Types of scoliosis
There are three main types of scoliosis: idiopathic scoliosis, congenital scoliosis and neuromuscular scoliosis.
Idiopathic scoliosis
The word idiopathic means of unknown cause. This is the most common type of scoliosis. The cause of scoliosis has not been determined and there are likely many contributing factors.
Congenital scoliosis
The word congenital means present at birth. If your child has congenital scoliosis, the bones in their spine were not shaped properly from birth. The mis-shaped bones in their back can cause scoliosis. The curve may become more obvious as your child grows. An X-ray can show whether the bones in your child’s spine are mis-shaped.
The severity of the curve varies from child to child. Your child may already have large curves in their spine that developed early on in their life, or they may have a small curve that has just started to develop in their teenage years.
Neuromuscular scoliosis
If your child has neuromuscular scoliosis, the curve in their spine is caused by a muscle or nerve disease or condition. One condition that can cause scoliosis is muscular dystrophy, which weakens the muscles. Another is spastic cerebral palsy, which causes tight muscles.
Neuromuscular curves are usually diagnosed during childhood. Many of the conditions that cause neuromuscular scoliosis are genetic and involve many parts of the body. This is different from idiopathic scoliosis, which only involves the spine.
What does scoliosis look like?
Usually, the spine looks relatively straight when viewed from the front or back. In patients with scoliosis, the spine curves sideways, usually into the shape of an S or a C. An S-shaped curve is also called a double curve. A C-shaped curve is also called a single curve.
For more information about the different types of scoliosis curves, see What does scoliosis look like?.
What causes scoliosis?
Most children with scoliosis have idiopathic scoliosis. Researchers do not know what causes idiopathic scoliosis. Genetics might be one cause. There are many other theories including hormonal problems, abnormal bone or muscle growth and other factors that have not been identified. It is not known if these factors cause the scoliosis or are the result of scoliosis. Most researchers agree that more than one factor causes scoliosis.
Genetics
Scoliosis tends to run in families. In one study, about one in 10 people with scoliosis had a first-degree relative with scoliosis. A first-degree relative is a parent, sibling, or child. In the same study, about two in 100 people with scoliosis had a second-degree relative with scoliosis. A second-degree relative is a grandparent, grandchild, aunt, uncle, niece, nephew, or half sibling.
Growth issues
Scoliosis gets worse during puberty when teenagers are rapidly growing. Scoliosis patients are generally taller than their peers in early puberty, around ages eight to nine. Once patients hit age 10 and up, their height is about the same as everyone else their age.
Most children have rapid growth at the time of puberty but most do not develop scoliosis. This supports the idea that more than one factor may cause scoliosis.
How common is scoliosis?
Most scoliosis occurs at the onset of puberty, around the ages of 10 to 16 years of age. Of children and teens in this age group, 2% to 3% will develop scoliosis. There are equal numbers of males and females with small curves of less than 10 degrees. However, females tend to outnumber males (10 to 1) in curves greater than 30 degrees. Less than 10% of patients diagnosed with scoliosis will require surgery.
Will my child’s curve get bigger?
There are several factors that will affect whether your child’s curve will progress. For example, scoliosis is more likely to progress if they are very young, especially if they have not yet reached puberty.
If you want to learn more about the long-term follow-up of scoliosis patients, see What to expect in adulthood.
Who is at risk for getting a larger curve?
There are six main factors that can help predict whether the curve in your child’s spine will increase in size. These factors are related to their growth, whether their bones have stopped growing, and the type and size of the existing curve.
There is a greater risk that the curve(s) will increase:
- The younger they are at the time scoliosis is diagnosed.
- For girls, if they have not yet started their menstrual periods.
- If their bones are still growing at the time of diagnosis.
- If your child has a double (S-shaped) curve. S-shaped curves are more likely to get bigger than single (C-shaped) curves. This is a general statement, as some double curves can be well tolerated, since the two curves may "balance each other out”. To learn about the different curve patterns, see What does scoliosis look like?.
- The larger the curve(s) are when scoliosis is diagnosed.
Males with similar curves have about one-tenth the chance that the curve(s) will increase when compared to females.
Osteopenia may also increase risk
There is research that looks at decreased bone density (osteopenia) in the hip bone on the opposite side of the curve. Researchers found that patients with osteopenia in the hip were more at risk for having a more severe curve. It is not known whether the curve causes the decreased bone density or whether the decreased bone density causes the curve to get worse.
It is also not known whether calcium intake in the diet can affect scoliosis in any way.
Diagnosis
In order to diagnose scoliosis, your child requires an X-ray to view the bones in their back. These bones are called vertebrae. When viewed from the front or the back, the spine is normally in a straight line. If your child has scoliosis, the vertebrae will usually curve to form the shape of an S or C.
The size of your child’s curve will be measured. The curve may be small, medium, or large in size, and is measured by degrees:
- Small curves are 20 degrees or less.
- Medium curves are between 20 and 50 degrees.
- Large curves are greater than 50 degrees.
Will my child’s curve need treatment?
The need for treatment depends on the type and size of your child’s curve. In general:
- If your child has a small curve of less than 20 degrees, they may only need to be observed over time.
- If their curve is medium-sized, between 20 to 50 degrees, they may either be observed or treated with a brace.
- If they have a larger curve, greater than 50 degrees, they may require surgery.
There are many factors that your child’s surgeon will consider before recommending treatment:
- How old they are
- How large their curve is
- Whether your child is still growing
- Whether they have an S-shaped or C-shaped curve
- The progression of their curve: how fast the curve is increasing in size
- How your child feels about the look of their back
- Whether your child is experiencing complications, how severe they are, or is at risk of developing complications if the scoliosis is left untreated
- Whether your child is unhappy with the appearance of their back (if their scoliosis is idiopathic)
For more information about the treatment of scoliosis, see the "Treatment" section of the Scoliosis Learning Hub.
Complications
If your child has congenital scoliosis, they might have problems in other areas of their body. Almost 25% of children with congenital scoliosis have problems with their kidneys or urinary tract. Approximately 10% have congenital heart disease.
If your child has neuromuscular scoliosis, the curves in their spine may get larger and lead to more problems. For example, a child with neuromuscular scoliosis might find it hard to sit on their own. If they have a large curve and weak rib muscles, they may have problems with breathing.
Does scoliosis cause pain?
Sometimes scoliosis can be painful for patients. Researchers studying teens with scoliosis found that older teens, teens who had almost finished growing, and girls who had already started menstruating were more likely to have back pain associated with scoliosis. Factors that did not predict pain with scoliosis included family history of scoliosis and type and size of curve.
It is important to remember that 60% to 80% of the general population will have back pain in their lifetime. The stress involved with the diagnosis of scoliosis could expresses itself as back pain. Children with scoliosis need to talk with their doctor or orthopaedic surgeon about any pain they are experiencing.
Does scoliosis affect the heart and lungs?
Scoliosis can affect a person's ability to breath (lung function) because of the impact that it has on their ribcage. Lung function is how well the lungs are working. It is also called pulmonary function. For children with mild-moderate curves, their lung function is not typically severely affected. Your child’s lung function is assessed with tests done in a pulmonary function lab, and testing may be done if your child is booked for surgery. If your child has a mild-to-moderate curve, they will usually not require testing.
How is lung function tested?
Several tests can be done. In general, these tests look at:
- Lung capacity—how much air your child can move in and out of their lungs.
- How fast they can move this air in and out of their lungs.
- The stiffness of their lungs and chest wall. The chest wall includes the rib cage, diaphragm, and abdominal wall.
Can certain types of curves affect breathing?
In general, only thoracic (mid-back) curves have the potential to affect your child’s breathing. Smaller thoracic curves that are between 20 and 45 degrees can cause decreased lung function during heavy exercise. Scoliosis is unlikely to affect your child’s ability to do daily activities or moderate exercise if they have a small curve.
Thoracic (mid-back) curves between 45 and 88 degrees can cause decreased lung function during moderate exercise. However, physical exercise programs designed to train the lungs can improve lung function significantly.
Patients presenting late with curves over 100 degrees can have a reduced lung capacity by 50%. Curves greater than 120 degrees can lead to right-sided heart failure, which is when the right chamber of the heart has difficulty pumping blood to the lungs. Curves greater than 120 degrees can also cause breathing difficulties in everyday activities.
Early onset scoliosis can affect breathing
Early onset scoliosis is scoliosis that occurs in children before the age of five years. The cause is not known. While many of these curves remain stable and even disappear on their own, others may increase in size quickly. Without treatment, early onset scoliosis can lead to deformity of the chest and spine. This can lead to problems with breathing. Active treatment, such as spinal casting, spinal bracing, or spinal growth guidance (growing rods), is needed for these cases.