Aebi et. al classified adult scoliosis into three types
| Type | Features |
| I | Primary degenerative scoliosis Develops after skeletal maturity Minimal structural deformities Advanced degenerative changes Lumbar spine most common Asymmetric degeneration of disc and facet joints with osteoporotic fractures |
| II | Progressive idiopathic deformity Develops before skeletal maturity Symptomatic in adult life Cervical, thoracic or lumbar |
| III | Secondary degenerative scoliosis Secondary to pelvic obliquity, hip pathology or lumbosacral transitional anomaly Secondary to metabolic disease, osteoporosis, combined with asymmetric arthritic disease and/or vertebral fractures |