Diseased spine. Coloured X-ray of the dorso- lumbar region of the spine (frontal view) of a patient who presented with severe lumbar sciatica. Sciatica is a painful condition caused by vertebral discs exerting pressure on the sciatic nerve. In this case, the lumbar vertebrae of the lower back have been damaged by arthrosis, osteophytosis and scoliosis. Arthrosis is a degenerative joint disease, which causes damage to the cartilage and bones of a joint. Osteophytosis is the growth of new bone, or bony growths that limit the movement and flexibility of a joint. Scoliosis is a congenital curvature of the spine (in this case to the right).