Classification

Type I:

  • S-shaped curve in which both thoracic curve lumbar curve cross midline
  • Lumbar curve larger than thoracic curve on standing roentgenogram
  • Flexibility index a negative value (thoracic curve < lumbar curve on standing roentgenogram, but more flexible on side-bending)


Type II:

  • S-shaped curve in which thoracic curve and lumbar curve cross midline
  •  Thoracic curve < lumbar curve
  •  Flexibility index < 0


Type III

  • Thoracic curve in which lumbar curve does not cross midline (so-called overhang)


Type IV

  • Long thoracic curve in which L5 is centered over sacrum but L4 tilts into long thoracic curve


Type V

  • Double thoracic curve with T1 tilted into convexity of upper curve; upper curve structural on side-bending

Explanation

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Figures

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Reference(s)

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