Care of spinal conditions has become increasingly complex and confusing. Classification systems can help in understanding the subject matter at hand, but have exploded in numbers and complexity. Attempts at extracting classifications of spinal disorders are cumbersome and require careful study of numerous reference books without achieving a comprehensive overview in the end. This one of a kind reference text summarizes over 185 spine classification or severity measures with standardized art work, provides ratings and critical evaluations of pertinent strengths and weaknesses in a concise and systematic fashion and provides help in: studying spinal disease conditions; preparing informed treatment decisions; communicating individual patient disease severity; evaluating publications regarding treatment results and success; formulating spinal research projects; and, providing a scientific reference tool. The book is divided into two major systems - Disease severity: General disease severity; Instability; Osteoporosis; Stenosis; Spinal deformity; Degenerative disorders; Infection; Tumor; and, Heterotopic ossification. Trauma severity: General trauma scores; Spinal cord injury; and, Fracture classifications. All identified measures within each of category are formally reviewed and displayed in a unique visually friendly manner containing: a one of a kind compendium of high quality diagrams for each severity measure or classification system with unrivaled specificity and detail; the content of each measure and whether it incorporates the critically important ABCDs of disease severity including: an anatomical component, a biomechanical component, a clinical component, and the degree of severity component; a summary of the measures validity, reliability, and predictive ability with corresponding patient populations; an evaluation of each measure using our scoring criteria focusing on methodological rigor and clinical utility; and, an overall score for each measure rating the instrument's strength with respect to methodology and clinical utility.