Overview
The King classification is a historical classification for adolescent idiopathic scoliosis based primarily on coronal curve pattern. It was developed to guide selection of fusion levels in posterior surgery and has largely been superseded by the Lenke classification.
Type I
- Double curve
- Both thoracic and lumbar curves cross the midline
- Lumbar curve is larger and less flexible than the thoracic curve
Type II
- Double curve
- Both curves cross the midline
- Thoracic curve is larger and less flexible than the lumbar curve
Type III
- Thoracic curve crosses the midline
- Lumbar curve does not cross the midline
Type IV
- Long thoracic curve
- L5 is centred over the sacrum
- L4 tilts into the thoracic curve
Type V
- Double thoracic curve pattern
- Upper thoracic structural component with T1 tilt
Limitations
The classification has limited reliability and does not adequately describe sagittal alignment, lumbar modifiers or many modern three-dimensional considerations. Lenke classification is preferred for contemporary surgical planning.
References
- Orthobullets. King Classification of AIS.