Posterior instrumentation in scoliosis.

The aims of posterior fusion and instrumentation in scoliosis are to achieve and maintain correction of the deformity and balance the spine in three planes, whilst keeping the fusion as short as possible and protecting the spinal cord. Harrington developed the first generation of posterior instrumentation, which considered only frontal plane correction. Since that time there has been an evolution from biplanar correction, addressing the frontal plane and sagittal plane, to triplanar correction, also addressing spinal derotation, and, most recently, to segmental derotation of strategic vertebral bodies.