Scoliosis is defined as a lateral curvature of the spine that is usually accompanied by rotation. Scoliosis is not a diagnosis, but a description of a structural alteration that occurs in a variety of conditions. Progression of the curvature during periods of rapid growth may result in significant deformity, which may be accompanied by cardiopulmonary compromise.
The clinical features, diagnosis, and initial evaluation of adolescent idiopathic scoliosis will be reviewed here. The management and prognosis of adolescent idiopathic scoliosis is discussed separately. (See "Adolescent idiopathic scoliosis: Treatment and prognosis".)
Terminology — 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) defines a scoliosis (image 2) . Curves with Cobb angle of less than 10º are referred to as spinal asymmetry and are of 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 vertebra that is most deviated and rotated from midline, called the apical vertebra . (See 'Radiographic evaluation' below.)
Etiologic classification of scoliosis — There are three broad categories of scoliosis: neuromuscular, congenital, and idiopathic (table 1):