(based on classification of King et al) assistance provided by Ben Allen Jr. M.D.

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- See: Selection of Fusion Level: 
- Discussion: 
- consists of a major thoracic curve (does not cross mid-line) and a flexible secondary lumbar curve; 
- treatment: 
- distraction is the primary form of treatment; 
- fusions should not end at the thoraco-lumbar junction but rather extend to at least to L2; 
- no down going hooks are placed in thoracic spine; 
- two hooks cannot be placed at the same level, but are rather staggered to avoid the risk of posterior arch frx; 
- concave side of curve: 
- major corrective force is achieved w/ distraction from end hooks; 
- superior up-going hook is placed one level above end vertebrae; 
- middle up-going hook is placed at apex of curve; 
- fusion usually needs to extend past L2; 
- down going hook is placed two levels below end vertebrae 
- convex side of curve: - these are staggered relative to concave hooks; 
- distal down going hook is placed one level above ditsal concave hook; 
- if the shoulder is high on the concave side, then the convex up-going hook is placed one level caudad relative to the concanve hook; 
- w/ severe asymmetry, the hook is placed two levels caudad; 
- note: distraction on the concave side may elevate the ipsilateral shoulder; 
- in this case, the shoulder will be low on the concave side, and therefore, the convex up-going hook is placed on level cephalad relative to the concanve hook; 
- w/ severe asymmetry, the hook is placed two levels cephalad; 
- treatment pitfalls: shoulder height asymmetry

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The selection of fusion levels in thoracic idiopathic scoliosis