Scoliosis sideways deformity of the spine of a woman, coloured X-ray. The spine (upper centre) is severely bent. The deformity affected the patient's posture, leading to severe erosion of both hip joints (lower left and right). The hip joint at lower left has been replaced by a prosthesis (black). Scoliosis may be due to a congenital abnormality of the vertebrae (spinal bones), a spinal injury or a disease such as poliomyelitis. The disease may start in childhood for no obvious cause, and progresses until growth stops, often causing severe deformity. Treatment is of the underlying cause, or immobilisation of the spine with a brace or by spinal fusion.