Idiopathic scoliosis

Last updated: October 5, 2022

Summarytoggle arrow icon

Idiopathic scoliosis is a deformity of the spine characterized by lateral deflection and rotation of the vertebral bodies. The disease typically presents in patients 10–12 years of age and is seen more commonly in girls. The most common pattern of scoliosis is a right convex curvature of the thoracic spine, resulting in forward rotation and protrusion of the right shoulder. Initially, patients do not experience any symptoms. The disease is often diagnosed incidentally or following manifestation of obvious skeletal deformities. Since scoliosis is a progressive condition, later symptoms can include pain and reduced mobility due to degenerative lesions of spinal discs and vertebrae. In severe cases of spinal deformity, patients may show signs of pulmonary restriction, including dyspnea and difficulty breathing. Scoliosis is a clinical diagnosis that is confirmed by typical findings on x-ray (e.g., Cobb angle > 10°). Treatment initially consists of observation and the use of braces. In cases of severe or rapidly progressing scoliosis, surgical treatment is necessary.

Definitiontoggle arrow icon

Epidemiologytoggle arrow icon

  • Sex: > (∼ 5:1)
  • The spinal curvature deformity can progress in skeletally immature patients as they grow.


Epidemiological data refers to the US, unless otherwise specified.

Etiologytoggle arrow icon

Classificationtoggle arrow icon

  • According to age
    • ≥ 10 years: adolescent idiopathic scoliosis
      • >
      • Most frequent type (∼ 80% of cases)
      • Usually manifests as a right convex thoracic curvature
    • 4–9 years: juvenile idiopathic scoliosis [2]
      • >
      • Usually manifests as a left convex thoracic curvature
      • Deteriorates progressively [2]
    • 0–3 years: infantile idiopathic scoliosis
      • =
      • Often manifests as a convex thoracic curvature with bending to the left
    • Special type: congenital functional scoliosis
      • This term does not refer to a structural scoliosis, but rather to a functional (nonstructural) type that may occur during the first months of life.
      • It usually manifests as a C-shaped, elongated thoracolumbar curvature with bending to the left, showing only a small degree of rotation.
      • Usually heals spontaneously
  • According to the pattern of the curvature: C-shaped scoliosis, S-shaped scoliosis, double S-shaped scoliosis (triple scoliosis)
  • According to the apex of the major curvature
    • Cervical: C2 to C6
    • Cervicothoracic: C7 to T1
    • Thoracic: T2 to T11
    • Thoracolumbar: T12 L1
    • Lumbar: L2 and L4
    • Lumbosacral: L5 or below

Clinical featurestoggle arrow icon

  • Patients present because of noticeable deformities, which are especially visible on physical examination.
    • Evaluation of the spinal shape from the back of the head to the intergluteal cleft
    • Adam forward bend test (most important clinical test) may show :
    • Assessment of severity based on scoliometer measurements (see “Diagnosis”)
  • Respiratory and cardiopulmonary impairment in cases of severe thoracic deformity
  • Pain occurs secondary to degeneration, compression, or irritation of spinal discs and nerves.

The elevated part of the rib cage and the lumbar hump are always seen on the convex side of the deformity! In the most common form of scoliosis, the right convex thoracic curvature results in forward rotation and elevation of the right scapula.

Diagnosticstoggle arrow icon

Conventional x-ray

  • Indicated to evaluate necessity for treatment (see “Treatment” below”)
  • Performed in cases of deviations > 7° on scoliometer measurements
  • Evaluation of the lateral curvature (in anterior-posterior projection, full-length views)
    • Major curvature: highest deviation from the perpendicular
    • Minor curvatures: compensatory deviations from the midline above and below the major curvature
    • Cobb angle: refers to the angle between the following lines
      • 1. Perpendicular to a line drawn across the superior endplate of the highest affected vertebra
      • 2. Perpendicular to a line drawn across the inferior endplate of the lowest affected vertebra
  • Estimation of vertebral rotation (Nash and Moe method): assessment of the position of the vertebral pedicles is relation to the vertebral bodies
  • Evaluation of skeletal maturity based on lateral ossification of the apophysis across the iliac crest (Risser sign) → relevant for prognosis
  • Lateral bending imaging of the spine: evaluation of curve flexibility

Every school-aged child should undergo a physical examination of the spine in order to rule out scoliosis. Scoliosis is frequently an incidental finding.

Differential diagnosestoggle arrow icon

Secondary scoliosis

Leg-length discrepancy (short-leg syndrome)

  • Definition: A condition caused by a difference in length between each lower extremity that results in functional impairment, compensatory structural and gait abnormalities, and degenerative joint processes.
  • Etiology
  • Clinical features
  • Physical examination
    • Abnormalities in gait
    • Rotated pelvis
    • Unleveling of the sacrum
    • Lateral thoracic and lumbar curvatures
  • Diagnostics
  • Treatment
    • Nonsurgical approach
      • Observation: if a child has not reached skeletal maturity
      • Shoe-lifts
    • Surgical approach
      • Epiphysiodesis (surgical fusing of the growth plate)
      • Limb lengthening or shortening procedures

The differential diagnoses listed here are not exhaustive.

Treatmenttoggle arrow icon

  • Treatment based on the Cobb angle [1]
  • Bracing
    • 18 hours/day, if possible
    • Bracing is usually able to halt progression, but cannot cure the underlying condition.
  • Surgery


Referencestoggle arrow icon

  1. Konieczny MR, Senyurt H, Krauspe R.. Epidemiology of adolescent idiopathic scoliosis. Journal of Children's Orthopaedics. 2013; 7 (1): p.3-9.doi: 10.1007/s11832-012-0457-4 . | Open in Read by QxMD
  2. Juvenile Idiopathic Scoliosis. Updated: December 21, 2016. Accessed: December 21, 2016.
  3. Asher MA, Burton DC. Adolescent idiopathic scoliosis: natural history and long term treatment effects. Scoliosis. 2006; 1 (1): p.2.

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