Adult Scoliosis: Etiology and Classification

Adult spinal deformity is common and can have a significant and measurable impact on quality of life. Patients with adult scoliosis present with clinical symptoms and radiographic findings that differ from those seen in adolescent idiopathic scoliosis. Adult scoliosis is typically due either to progression of adolescent idiopathic scoliosis or to development of a de novo spinal deformity. The deformity is characterized by associated degenerative changes including spinal stenosis, spondylolisthesis, rotational or lateral subluxation, lumbar hypolordosis, and relative rigidity of the spinal deformity. The deformity and associated degenerative changes occur due to a vicious cycle of asymmetric loading of the spine, asymmetric degeneration, and asymmetric deformity. Although not perfect, the Scoliosis Research Society classification for adult spinal deformity provides the best mechanism by which adult spinal deformity may be assessed.