Fig. 33.

A composite structural scoliosis, main thoracic and lumbar is compatible with N3N4 and it is called C2 type. It can be major thoracic/minor lumbar or double major but we have not seen any N3N4 with lumbar structural curve where the lumbar component was major and the thoracic minor. The second radiological criterion is the TP and T1 on the CSL. Minimal offset (±4 mm) is considered not a reason to reject diagnosis of C2. The third radiological criterion is a L4–L5 negative counter-tilting (it can be observed a mild false positive counter-tilting, for example due to leg length discrepancy or pelvis asymmetry)