Derotation of the spine.

Idiopathic scoliosis is a three-dimensional deformity: lateral deviation in the coronal plane, thoracic hypokyphosis in the sagittal plane, and rotation in the transverse plane affecting the ribs and trunk. With pedicle screw fixation and modern corrective techniques, derotation of the spine can now be accomplished. The goals of vertebral derotation are to achieve true three-dimensional correction of the spinal deformity and reverse the torsional asymmetry induced by scoliosis. Intuitively, in typical thoracic adolescent idiopathic scoliosis, this would mean optimal coronal correction, restoration of thoracic kyphosis, and realignment of thoracic torsion by lifting the concavity out of the chest and reducing the convex rib deformity without the need for thoracoplasty.