What Is Scoliosis and What Causes It?
If you look at someone’s back, you’ll see that the spine runs straight down the middle. When a person has scoliosis, their backbone curves to the side.
The angle of the curve may be small, large or somewhere in between. But anything that measures more than 10 degrees is considered scoliosis. Doctors may use the letters “C” and “S” to describe the curve of the backbone.
You probably don’t look directly at too many spines, but what you might notice about someone with scoliosis is the way they stand. They may lean a little or have shoulders or hips that look uneven.
What Causes Scoliosis?
In as many as 80% of cases, doctors don’t find the exact reason for a curved spine. Scoliosis without a known cause is what doctors call “idiopathic.”
Some kinds of scoliosis do have clear causes. Doctors divide those curves into two types — structural and nonstructural.
In nonstructural scoliosis, the spine works normally, but looks curved. Why does this happen? There are a number of reasons, such as one leg’s being longer than the other, muscle spasms, and inflammations like appendicitis. When these problems are treated, this type of scoliosis often goes away.
In structural scoliosis, the curve of the spine is rigid and can’t be reversed.
- Cerebral palsy
- Muscular dystrophy
- Birth defects
- Genetic conditions like Marfan syndrome and Down syndrome
Congenital scoliosis begins as a baby’s back develops before birth. Problems with the tiny bones in the back, called vertebrae, can cause the spine to curve. The vertebrae may be incomplete or fail to divide properly. Doctors may detect this condition when the child is born. Or, they may not find it until the teen years.
Family history and genetics can also be risk factors for idiopathic scoliosis. If you or one of your children has this condition, make sure your other kids are screened regularly.
Scoliosis shows up most often during growth spurts, usually when kids are between 10 and 15 years old. About the same number of boys and girls are diagnosed with minor idiopathic scoliosis. But curves in girls are 10 times more likely to get worse and may need to be treated.
Scoliosis diagnosed during the teen years can continue into adulthood. The greater the angle of the spine curve, the more likely it is to increase over time. If you had scoliosis in the past, have your doctor check your back regularly.
Degenerative scoliosis affects adults. It usually develops in the lower back as the disks and joints of the spine begin to wear out as you age.
The goal of treatment for scoliosis is to prevent the spinal curve from getting worse and to correct or stabilize a severe spinal curve. Fortunately, few people who have spinal curves require treatment.
The type of treatment depends on the cause of scoliosis. Scoliosis that is caused by another condition (nonstructural scoliosis) usually improves when the condition, such as muscle spasms or a difference in leg length, is treated. Scoliosis that is caused by a disease or by an unknown factor (structural scoliosis) is more likely than nonstructural scoliosis to need treatment.
- Nonsurgical treatment. This includes either routine exams by a doctor to check for any curve progression or the use of a brace to stop a spinal curve from getting worse. Children typically have these checkups about every 4 to 6 months.
- Surgical treatment. Surgery can usually decrease the curve and stabilize the spine so the curve does not get worse.
Treatment is based on the child’s age, the size of the curve, and the risk of progression. The risk of progression is based on age at diagnosis, the size of the curve (as measured using X-rays of the spine), and skeletal age (which can be determined by the Risser sign).
- Mild curves are usually checked by the doctor every 4 to 6 months until the bones stop growing, to be sure the curves aren’t getting worse.
- Moderate curves may need to be braced until the bones stop growing, to keep the curves from getting worse.
- Severe curves or moderate curves that are getting worse may need surgery.
What to think about
Most cases of scoliosis are mild and do not require treatment.
The timing of surgery for scoliosis in children is controversial. Spinal fusion stops the growth of the fused part of the spine, so some experts believe that surgery should be delayed until the child is at least 10 years old and preferably 12. But even after surgery the rest of the spine will continue to grow normally in children who are still growing.