AIS - Adolescent Idiopathic Scoliosis


Scoliosis is a lateral or side to side curvature of the spine along with a twisting of the spinal column. The most common type of scoliosis seen in children is adolescent idiopathic scoliosis (AIS). AIS is defined as scoliosis whose onset occurs after 10 years of age, and whose cause is essentially unknown.

There are no identifiable causes for this condition yet, but there are many theories.

Natural history

In general, AIS curves progress in two ways:

1. during the rapid growth period of the patient, that is the period of rapid growth around the time of puberty.

2. into adulthood if the curves are relatively large. Some studies suggest the curve needs to be above 60 degrees to be a problem in later life 

Radiographs of the spine and pelvis are also used to determine growth. The iliac crest growth platre is part of the the Risser grading system. It is often used to determine a child's skeletal maturity (how much growth is left) on the pelvis, which correlates with how much spine growth is left. The Risser grading system rates a child's' skeletal maturity on a scale of 0 to 5. Patients who are Risser 0 and 1 are growing rapidly, while patients who are 4 and 5 have stopped growing.


Scoliosis patients need to have specialist radiographs done to assess the condition. The typical radiographic images that are obtained include a standing X-ray of the entire spine looking both from the back (AP radiograph), as well as from the side (lateral radiograph). We tend to perform these with lead shields to protect you from radiation. We will be able to measure the radiographs to determine your curves magnitude, which is measured in degrees using the Cobb method.

MRI scans are not usually required. They may be ordered if there are any typical features on your X-ray or if you doctor finds anything abnormal during neurological examination.


Treatment of adolescent idiopathic scoliosis falls into three main categories




Bracing tends to be used in patients with smaller curves (less than 20o)  to prevent curve from progressing and to correct any cosmetic changes.

Surgical treatment is offered to patients whose curves are greater than 45 while still growing or greater than 50 when growth has stopped. The goal of surgical treatment is two-fold: First, to prevent curve progression and secondly to obtain some curve correction. Surgical treatment today utilizes metal implants which are attached to the spine, and then connected to a single rod or two rods. Implants are used to correct the spine and hold the spine in the corrected position until the spine segments which have been operated on are fused as one bone.

Many factors go into the decision as to the surgical approach. Following surgical treatment, no external bracing or casts are used. The hospital stay is generally between 5 and 7 days. The patient can perform regular daily activities and generally returns to school in 3-4 weeks.

Risks and Benefits of Surgery

  • Improved cosmetic appearance
  • Reduced prominence of the rib hump
  • Prevention of the curve getting worse
  • Risk of infection with surgery
  • Small (less that 0.5% ) risk of paralysis
  • Risk of other serious complication that are infrequent, they should be discussed with your surgeon

Long term outcome

Back pain in scoliosis tends to be the same as in the general population.

A survey has shown that in the long term after surgery, some people tend to have back pain that limits travel and decreases physical function. Some have a poor self image and perceive themselves less healthy. However, those who have undergone surgery in the long term have a good sense of psychological well being as the general population.

There has been no difference shown in the reproductive experience of women with scoliosis. The incidence of delivery by Caeserean section and health problems in pregnancy are no greater than in women without scoliosis.