Ideopathic scoliosis is a curvature of the spine. If the curvature is severe enough, a spinal fusion surgery may be indicated.
The following link shows an animation of a minimally invasive fusion technique.
During the procedure, the neurophysiologist is continually testing the integrity of the long tracts that travel the length of the spinal cord. The sensory and motor tracts can be tested using evoked potentials.