Classification systems are developed to enable a more universal understanding of pathologies that are commonly encountered in clinical settings and to standardize the treatment approach. The current classification systems for adult scoliotic deformity are easy to understand. However, there are no other surgical recommendations other than fusion. Nonetheless, most of these pathologies are amenable to surgical treatment with dynamic systems before excessive disease progression. In almost all classifications, the first stages can be treated with dynamic systems instead of fusion. Fusion should be used in the treatment of advanced rigid deformities and as part of the hybrid approach involving the use of rigid systems and dynamic systems.