The word is a combination of kyphosis - excessive outward curvature of the spine - and scoliosis - excessive sideways curvature of the spine. It may occur for no known reason (idiopathic kyphoscoliosis) or as a result of a disease which affects the vertebrae and spinal muscles (for example osteoporosis or ankylosing spondylitis. Treatments include wearing an unsightly and no doubt really uncomfortable back brace, or surgery to fuse the spine. Ouch.