Scoliosis

Definition & terminology

  • Scoliosis
    • Deformity is in three planes with lateral, anteroposterior & rotational components
    • Cobb angle is > 10° on standing X-ray
    • Curvatures of 10° or less should be described as spinal asymmetry
  • Postural scoliosis
    • secondary or compensatory to some condition outside spine, such as short leg, or pelvic tilt
    • When condition is corrected or compensated for scoliosis is abolished
    • Postural scoliosis does not have rotational component
  • Structural scoliosis
    • non-correctible deformity of affected spinal component, essential component of which is vertebral rotation
  • Apex of Curve
    • most laterally deviated disc or vertebra of curve. Usually single vertebra can be defined as apical vertebra, but if there is pair of vertebra at apex intervening disc can be defined as apical disc
  • End vertebrae
    • vertebrae most tilted from horizontal
    • These define proximal & distal extent of curve (& are used to measure Cobb angle)
  • Neutral vertebrae
    • first superior & inferior vertebrae around curve that are not rotated
  • Primary / Secondary curves
    • Primary curves are first curves to develop & these may be followed by secondary or compensatory curves which function to keep head balanced over sacrum
    • Primary curves are more likely to become fixed, & secondary curves are more mobile
  • Central Sacral Line
    • vertical line from midline of sacrum
  • Normal Sagittal plane angles
  • Thoracic Kyphus (10 to 50, avg 35)
  • Lumbar Lordosis (40 to 80, avg 55)