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Adolescent idiopathic scoliosis: Clinical features, evaluation, and diagnosis

Susan A Scherl, MD
Section Editor
William Phillips, MD
Deputy Editor
Mary M Torchia, MD


Scoliosis, lateral curvature of the spine, is a structural alteration that occurs in a variety of conditions. Progression of the curvature during periods of rapid growth can result in significant deformity, which may be accompanied by cardiopulmonary compromise.

The clinical features, diagnosis, and initial evaluation of adolescent idiopathic scoliosis (AIS) will be reviewed here. The management and prognosis of adolescent idiopathic scoliosis are discussed separately. (See "Adolescent idiopathic scoliosis: Management and prognosis".)


Scoliosis is defined as curvature of the spine in the coronal plane (image 1). It is typically accompanied by a variable degree of rotation of the spinal column. By convention, ≥10º of curvature (as measured by the Cobb angle (image 2)) defines scoliosis [1]. Curves with Cobb angle <10º are within the normal limits of spinal asymmetry and have no long-term clinical significance. The direction (right or left) of a scoliotic curve is defined by the curve's convexity (image 1). The location is defined by the apical vertebra (the one that most deviated and rotated from midline) [2]. (See 'Radiographic evaluation' below.)

Idiopathic scoliosis is scoliosis for which there is no definite etiology unlike neuromuscular, congenital, or syndromic types. (See 'Differential diagnosis' below.)

Idiopathic scoliosis is divided into three subcategories based upon the patient's age at presentation:


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