King classification of idiopathic scoliosis

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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