Table 1.

Curve classification

Curve types according to the Lenke classification system [42]		Lumbar modifier
		A	B	C
1 (Main thoracic)	10	5	1	4
2 (Double thoracic)	3	2		1
3 (Double major)	4			4
4 (Triple major)
5 (Primary thoracolumbar/lumbar)
6 (Primary thoracolumbar/lumbar, structural thoracic)	4			4