Lenke 6

Lenke 6 curves have structural thoracolumbar/lumbar and main thoracic curves, with thoracolumbar/lumbar curve being larger than the main thoracic curve.

Due to the morphology of type 6 curves lumbar modifiers A and B do not exist.

A minor curve is defined as structural if at least one of the two below criteria are met:

• Residual curve greater than or equal to 25 ° on supine bending radiograph
• T2 – T5, T10-L2 kyphosis greater than or equal to 20 ° (regardless of coronal flexibility)

Same definition applies for proximal thoracic curves.

The lumbar modifier is determined by drawing a vertical line from the center of the sacrum.

The sagittal modifiers are determined from the lateral radiograph from T5-T12. A measurement less than 10° is designated as "-".

Measurements between 10°-40° is designated as "N".

A measurement larger than 40° is designated as "+".