Adolescent Idiopathic Scoliosis (AIS)

“Scoliosis” is a condition that causes a curvature of the spine when viewed straight on (the frontal plane). By far the most common form of scoliosis in young patients is “idiopathic”, meaning the cause is unknown and primarily affects adolescents during their growth spurt.  Adolescent Idiopathic Scoliosis (AIS) effects 2-3% of the children from the ages 10-16. Most cases are mild and do not have a significant impact on activity level or quality of life. A small percentage of curves will progress, particularly during growth, and may require treatment with a brace. Curves that progress beyond 40-50 degrees are usually treated surgically.  


Scoliosis actually involves rotation of the vertebral bodies which is primarly seen as a curvature in the frontal plane but also involves abnormal curvatures when seen from the side (sagittal plane).  Research has not revealed a definitive cause although genetics clearly plays a role. However, specific behaviors such as carrying a backpack or poor posture have no relationship to the development or progression of scoliosis.


Most cases of idiopathic scoliosis are mild and may go unnoticed and undiagnosed. Symptoms are more likely to be develop following progression of the curve during the adolescent growth spurt. Family members or friends are often the first to notice changes in posture or balance as the curve increases. These include tilted, uneven shoulders, a protruding, asymmetric shoulder blade, mid back or rib prominence, or an uneven waistline or elevated hip. Patients may also notice a change in the way clothing fits or an asymmetric hemline.  As many as 30% of patients complain of some degree back pain however significant pain is unusual and should prompt further diagnostic workup.


As noted earlier scoliosis usually does not develop symptoms until the curve has progressed to the point of developing observable structural changes. As a result, patients may be diagnosed too late for non operative treatment with a brace. Many states and countries therefore mandate school screening to identify potential curves for further medical evaluation. This involves the child bending forward (Adams forward bending test) while a trained clinician looks for evidence of spinal asymmetry. Children thought to have significant asymmetry are referred to a spine specialist for further evaluation. Clinical diagnosis is based on scoliosis xrays with a measurable curve greater than 10 degrees. Most structural curves involve the thoracic spine with compensatory curves in the upper thoracic spine and lower lumbar spine.


Most patients diagnosed with scoliosis have mild curves and require no definitive treatment although observation is recommended until maturity. Curves that are >25 degrees with significant growth potential are often treated with a brace to stop curve progression. Studies demonstrate bracing is effective and decreases progression and the need for surgical treatment. Bracing is dose dependent (the more its worn the more likely it will decrease progression) and continued until skeletal maturity. There are various bracing options available which usually involve custom molded plastic braces that are worn beneath clothing and removed for sporting activities and hygiene.  

Curves that progress to >45 degrees are usually treated surgically. This typically involves a posterior spinal fusion and instrumentation of the structural curve although anterior spinal fusion and instrumentation is appropriate in a minority of cases. Minimally invasive techniques employing DLIF, ALIF, and TLIF procedures are also being used more frequently. Goals of surgery include curve correction (70-80%) while maintaining spinal balance and motion segments of the lower lumbar spine. The further a fusion extends across the motion segments of the lower lumbar spine the more likely patients will develop adjacent segment degenerative changes and back pain later in life.

Further Information

Case Study 4: 17 yo woman with progressive adolescent curve despite bracing

Case Study 5: 38 yo woman with untreated adolescent scoliosis that has progressed over the years and came to include disabling back pain.

Case Study 6: 17 yo young male with progressive scoliosis and imbalance despite non operative treatment with bracing.

Case Study 7: 16 yo girl with progressive scoliosis despite bracing.

Download our Scoliosis Handout


Hepler M, Birven S, Watkins-Castillo S. Scoliosis and Spinal Deformity in Children. Burden of Musculoskeletal Diseases in United States (BUMUS). Third edition 2014.