What is Adolescent Idiopathic Scoliosis?

Adolescent idiopathic scoliosis (also known as AIS) is the most common cause of scoliosis and spinal deformity in children.  “Adolescent” means that the patients affected are in their teenage years, 10 years or older, and still have growth remaining.  “Idiopathic” means that the precise reason for the disease is not known.

Scoliosis is a three-dimensional deformity of the spine, but it is most noticeable as a curvature of the spine to the right or left when a person is viewed from the back.  The rotational deformity of the spine is noticeable as an asymmetry in the back when someone bends forward.

Adolescent idiopathic scoliosis affects approximately 3% of the population, but only a small number of those develop curves large enough to require active treatment.  Girls are much more likely than boys to develop large curves that require treatment with bracing or surgery.

Adolescent Idiopathic Scoliosis Causes

The cause of adolescent idiopathic scoliosis is unknown.  Adolescent idiopathic scoliosis is known to run in families and thus the cause is partially genetic, but it is not yet fully known what other factors might contribute to the development of scoliosis.

Scoliosis is NOT caused by wearing a heavy backpack, poor posture, or sleeping on one’s side.

Adolescent Idiopathic Scoliosis Symptoms

The symptoms of adolescent idiopathic scoliosis depend greatly on the size of the curve.  For small curves between 10-20 degrees, typically there are no symptoms at all.

When curves become bigger in the 20-30 degree range, teenagers may notice that one shoulder is higher than the other, or that one hip sticks out more.

They may notice that their clothing does not fit quite properly. In a bathing suit one shoulder blade may appear more prominent than the other. When bending forward there will be a noticeable asymmetry in the rib cage or prominence of the lower back muscles.  

Adolescent idiopathic scoliosis itself is not associated with back pain.  If severe back pain is present along with AIS then other causes for the back pain need to be investigated.

Adolescent Idiopathic Scoliosis Diagnosis

Your physician will diagnose scoliosis based on the following criteria:

  • History: To diagnose the problem, your doctor will ask about your child's past and present medical history, as well as any family history of scoliosis.
  • Physical Examination: Your doctor will perform a physical examination using the forward bending or Adams test, to define the curve.
    • Adams Forward Bend Test: During this test, the child is asked to bend forward with the arms extended forward. Your doctor looks for the symmetry of the hips and shoulders, and the curvature of the spine from the sides, front and the back. Any abnormalities along the back could be a sign of scoliosis.
  • X-ray: X-ray of the spine is taken from the front and the side to confirm the diagnosis and also to measure the degree of the curvature.
  • Neurological Examination: Here the patient’s reflexes are tested and any neurologic changes are noted.

Scoliosis is often self-diagnosed by teenagers who notice an asymmetry in their back, shoulders, or hips.  Scoliosis is also commonly diagnosed during well child visits at the pediatrician or by parents who notice an asymmetry in their child’s spine.  

The assessment of adolescent idiopathic scoliosis begins with a detailed history including when the curvature was first noticed and questions to get a sense of how much growth the child has remaining.

For girls, the date of their first period (first menarche) is important to know as girls tend to grow for approximately 2 years after they have their period for the first time.

A family history of scoliosis, especially if family members required bracing or surgery, is important to note because of the genetic component of scoliosis.

The physical examination focuses on examining the child’s overall posture when standing. This includes evaluation of shoulder balance, any leg length discrepancies, and rotation of the ribs and waistline.

The doctor will examine your child’s back and perform an Adam’s Forward Bend test. This allows the doctor to measure the rotation of the spine using a device called a scoliometer.

If the scoliometer measurement is greater than 7 degrees, this suggests the diagnosis of scoliosis and an x-ray of the entire spine should be performed for a more precise measurement of the size of the curve.

The doctor will also examine the patient for any suggestion of other conditions that could be causing the scoliosis such as congenital anomalies, connective tissue disorders (such as Ehlers Danlos syndrome or Marfan’s syndrome), or neurofibromatosis.

Lastly, a neurological examination is performed to rule out spinal cord anomalies that could be causing the scoliosis.

X-rays are critical to properly evaluating adolescent idiopathic scoliosis and to guide treatment. X-rays should include the entire spine from the bottom of the skull to the pelvis to allow a thorough evaluation of overall spinal balance, the size of the curves, and to allow visualization of the growth plates in the pelvis (Risser sign) that can provide information about how much growth the child might have remaining.

On the x-rays, the doctor will measure the Cobb angle which is the angle formed between the most curved vertebrae.

The definition of scoliosis is at least a 10 degree curvature as measured by the Cobb angle. Most curves are between 10 and 40 degrees in size.

Nonsurgical Management of Adolescent Idiopathic Scoliosis

Unfortunately there are no proven nonsurgical methods of treatment that have been shown to correct scoliosis or reduce curve size; rather, treatment is directed towards preventing any further growth of the curves.

Thankfully, small curves are typically asymptomatic, do not cause pain or significant deformity, and surgery is not necessary.

  • Observation: If scoliosis is mild with a curve of less than 15 to 20 degrees, the child is observed for a specified period of time, to monitor the curve.
  • Bracing: Bracing is recommended to prevent the progression of the scoliotic curve. It is effective in growing children with a spinal curvature between 20° and 40°.

Physical therapy including the Schroth method, spinal mobilization, and chiropractic treatment can be used to help with some of the symptoms of scoliosis but have not yet been proven to change the natural history of scoliosis.

The treatment of adolescent idiopathic scoliosis depends on how large the curve is at initial diagnosis and how much growth of the curve is expected with time.

Curves that are small at initial presentation (less than 20 degrees) in a child close to being done with growth does not need any active treatment as the curve is unlikely to grow much larger.

Checkups every 6 months or so until the child is done with growth is all that is necessary.

If the child has a larger curve (25 to 35 degrees) and still has significant growth remaining, then bracing with a Boston-style TLSO brace is recommended.

A recent study published in the New England Journal of Medicine, the BRAIST trial, showed that these types of braces slow or stop the progression of scoliosis in most cases.

Bracing success depends on the amount of time the brace is worn, and it is recommended that the braces be worn at least 14 hours a day while the child is awake.  

The main goal of adolescent idiopathic scoliosis treatment is to try to prevent curves from getting bigger than 45 to 50 degrees.

When the scoliosis becomes this large, non-surgical methods are largely ineffective and the scoliosis will continue to grow even when the child is done with their growth. As the curve continues to grow into adulthood, it can result in a progressive deformity, increasing back pain, and if the curves become very large (greater than 80 degrees), they even can affect heart and lung function.

Adolescent Idiopathic Scoliosis Surgery

Curves that progress to larger than 45 to 50 degrees have been shown to progress 0.5 to 1 degree per year even after kids are done with their growth.

This means that a 50 degree curve at age 15 may become an 80 degree curve by age 45! Because curves this size tend to continue to grow into adulthood, surgery is recommended to correct and stabilize large curves.

Surgery for scoliosis in the past used to require being placed in a full body cast after surgery and months of pain and a slow recovery.

Surgical techniques for the treatment of scoliosis have improved dramatically! Today, spinal fusion surgery for adolescent idiopathic scoliosis is almost exclusively performed with an incision in the back (rather than through the chest or abdomen) and the curves are corrected using screws and rods to pull the spine back into a more optimal position.

Kids are typically discharged from the hospital after 3 or 4 days and they can return to all of their normal activities (including sports) at 3 months after surgery.

The decision to undergo surgery for adolescent idiopathic scoliosis is a challenging one.

The expert team at Raleigh Orthopaedic Clinic is trained in the latest techniques for scoliosis surgery and is committed to performing the least invasive procedure with the least amount of risk for each patient.

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