Adolescent Idiopathic Scoliosis
Scoliosis is an abnormal curvature of the spine that affects approximately seven million people in the United States. Scoliosis is a condition where the spine curves abnormally to the right or left side and also involves a twisting or rotation of the bones of the spine.
- Adolescent Idiopathic Scoliosis
- Dr. Good Explains
- Risk Factors
- Genetic Testing
Adolescent idiopathic scoliosis (AIS) is the most common form of scoliosis and typically affects children who are at least 10 years old. The term adolescent means that a patient is not yet skeletally mature, meaning that they are still growing. The term idiopathic means "occurring without known cause." Idiopathic scoliosis affects 2-3% of children aged 10-18 years old and is more common among females than males. In idiopathic scoliosis, the specific cause is unknown; however it is largely thought to be a genetic disorder.
For patients with adolescent idiopathic scoliosis, the parent or patient are usually the first to notice scoliosis but sometimes it is not discovered until a school screening or a doctor's visit. Most patients with AIS do not have many symptoms, but larger curves may cause a noticeable deformity, such as a rib hump, or pain. In severe cases the curve may even begin affecting heart or lung function.
The symptoms of scoliosis vary based on the severity of the curve. Some patients with AIS first notice that their clothes no longer fit correctly. Most patients with AIS do not have many symptoms, but large curves may cause noticeable deformity. Many children may hide their scoliosis well, especially with loose clothing and layers worn in cooler climates. Remember that scoliosis tends to run in families so if you or other relatives have scoliosis, keep an eye on your child’s back. Often a school screening or an annual pediatrician visit may show concern for scoliosis and refer you for an evaluation. In our office, we will examine your child’s back for subtle difference and measure any curvatures.
Scoliosis can reveal itself in many ways:
- The shoulders may not be level with one side elevated.
- Your child may lean to the right or left or have a hard time standing up perfectly straight.
- The back itself may look different. One shoulder blade may be more prominent in the back or you may notice a rib hump.
- If your child bends forward at the waist one side of the back may appear higher than the other.
- The sides of the low back may have uneven skin folds where one side indents more than the other.
- Your child’s hips may be uneven where the underwear or pant line always appears crooked.
- You may notice a leg length discrepancy where one pant leg is always longer or even an abnormal walking pattern.
When an adolescent is first seen for a scoliosis evaluation a complete medical history will be taken.
A history will include details to help understand how much growth a child is expected to still have. As AIS has a strong genetic component, a family history is important to include.
A physical exam will include a complete neurologic examination and the use of a special level called a scoliometer. This tool is used to measure the asymmetry of the spine when the spine is bent forward.
X-rays of the entire spine are taken to evaluate the front and side curvature. Your child will stand up straight and need to stand still for a short time. We use these x-rays to make specialized measurements called Cobb angles to measure the degree of the curve. The Cobb angle is used on x-ray to measure the angle between the most angulated vertebras that make up the curvature. Lines are drawn on the x-ray or a computer program assists to calculate the angle. Most scoliosis curves are between 10 to 40 degrees in magnitude. Although radiographic measurements are used to decide treatment, a small degree of error exists when comparing radiographs. A change of 5 degrees is usually needed to document an actual change in curve progression.
A cobb angle is measured from x-rays to evaluate the degree of curvature.
There are a number of factors that may be related to the risk for AIS progression. These include the patient’s age, skeletal maturity, gender and pattern of the scoliosis curve present. Overall, being diagnosed with scoliosis at a younger age means there is a higher chance of curve progression and girls are more likely to have curves progress to require treatment.
Age: Being diagnosed with scoliosis at a younger age means there is a higher chance of curve progression. This is because the curve progresses most during the growing years in adolescence. The younger you are diagnosed, the more your bones have to grow thus, you are more likely to have your curve progress while you grow. The natural history of scoliosis has been studied in untreated scoliosis children and the following statistics are from a 1984 study published in Journal of Bone and Joint Surgery by Lonstein and Carlson. In this study for children 10 years or younger, a small curve (from 5-19 degrees) has a 45% chance of progressing however a medium curve (from 20-29 degrees) has nearly a 100% chance of progressing. This decreases as the child becomes older. For medium sized curves, at 11-12 years old there is a 61% chance of progression and by the time you are 15 or older, only a 16% chance of progressing. Later studies have demonstrated very similar data.
Skeletal maturity: Skeletal maturity is another way to demonstrate how much growth a child has remaining. Certain growth plates close around certain ages for boys and girls. The Risser sign is a growth indicator in the pelvis that we see on scoliosis x-rays and refers to the amount of calcification of the human pelvis as a measure of skeletal maturity. It is graded on a scale from 0-5, with 5 being adult bone growth. In that same 1984 study for medium sized curves, a Risser sign of 0-1 shows 68% progression while those at grade 2-4 progressed by 23 percent. Again, the bigger the curve with more growth remaining means the curve will likely continue to progress.
Gender: Girls are much more likely to have scoliosis curves that progress to the point that treatment is required. For curves that are over 30 degrees, girls have a 10:1 ratio for progression over boys.
Pattern of Curve: Certain curves have a greater chance of progressing. There are four major curve types that are named after their location. A thoracic curve is one of the most common patterns in idiopathic scoliosis with 90% occurring on the right side. A double major curve describes a right thoracic and a left lumbar curve. Both of these two curves are the most common curve patterns to progress. A thoracolumbar curve is also quite common with 80% on the right side and a lumbar curve is usually found on the left side.
Here are two examples of front and side x-rays from girls with AIS.
It is widely accepted that genetic factors play a significant role in the development of adolescent idiopathic scoliosis. Recent breakthroughs have allowed researchers to develop specific genetic testing to be used for young patients with idiopathic scoliosis. A genetic test analyzes a specific panel of genetic markers from the patient's saliva collected during an office visit. Results are used to predict which patients are likely to progress to a severe scoliosis at the time of initial diagnosis. Understanding a patient’s risk of curve progression can alter treatment recommendations. The physicians at Virginia Spine Institute offer genetic testing as a part of a scoliosis evaluation if a child meets the genetic testing criteria.
Most patients with adolescent idiopathic scoliosis have small curves that do not require formal treatment. For patients with small curves, defined as 10◦ to 20◦, no formal treatment is required. For these patients, we observe the curve over time to determine if the curve is worsening while the patient grows.
Physical therapy, spinal mobilization techniques, or chiropractic treatment can be beneficial for treating symptoms of scoliosis however; none of these treatments are effective in reducing the size of the curvature. For growing patients, the curve is clinically observed over time to determine if the curve is worsening.
For patients with larger curves measured from 20◦ to 40◦ a brace may be used. Bracing treatment cannot correct scoliosis; however, the goal of the brace is to prevent further progression of the curve during the patient's growth spurt. For patients who need a brace, a light weight thoracolumbosacral (TLSO) brace is most commonly used. This light weight brace is custom molded to the patient's body and can be worn under clothes. It allows patients to still participate in most sports and activities. The brace is most effective when worn constantly and is recommended to be worn 22-23 hours a day.
A TLSO brace is a lightweight plastic brace that is molded to fit a person with scoliosis. The goal of a brace is to keep the curve from getting bigger during the growing years.
Curves that are 30° to 35° will likely progress into adulthood and can cause increasing back pain, accelerated disc degeneration, deformity and eventually problems with heart and lung function. Surgery for adolescent idiopathic scoliosis is usually necessary for patients whose curve is larger than 40° to 45 degrees. In these cases, surgery is the best option to prevent further progression of the curvature. The decision to undergo scoliosis correction surgery should only be made after a careful evaluation and discussion between the patient, the family, and the surgeon. Our expert team at Virginia Spine Institute is always committed to performing the least invasive procedures with the least amount of risk for each patient. Learn more about surgery for adolescent scoliosis.