Scoliosis is a sideways curve in the spine.  This acquired type is called “sciatic scoliosis”. It is thought to be the body’s way to splint the spine and reduce pressure on a spinal nerve from a disc protrusion.  

Depending on which side of a spinal nerve the disc protrusion is pressing, the curve, and may be toward or away from the painful leg. It can increases when bending forward.