ABSTRACT
Adult spinal deformity (ASD) is a complex group of pathologies comprising a broad range of radiographic patterns and clinical presentations. A deformity classification system is needed to characterize the clinical and radiographic features, guide management, and establish a common lexicon for ASD research. The original Schwab classification system was developed based on curve type, lumbar lordosis, and amount of intervertebral subluxation in the coronal plane. Recent studies have demonstrated that spinopelvic radiographic parameters are significantly correlated with health-related quality of life scores. These parameters include pelvic incidence, lumbar lordosis, pelvic tilt, and sagittal vertical axis. The chapter aims to create and validate a classification system that incorporates these key radiographic parameters by updating and improving the current Schwab classification system. Classification systems for spinal deformity were originally developed for pediatric deformity. In particular, the Lenke classification for adolescent idiopathic scoliosis gained widespread acceptance.
