As modern science and medical technology increase the life span of man, the human skeleton is required to function for longer periods of time. Many skeletal problems that besiege the adult stem from abnormalities that exist during infancy and adoles­ cence. These may be congenital problems or acquired problems due either to a child's environment or to some injury sustained during the growth years. Adolescents today are extremely active; many sports and hobbies subject them to an infinite array of traumatizing episodes that may result in injuries and diseases. When I wrote the first edition of The Adolescent Spine in 1976, I felt it pertinent to produce a work which would help medical students and practitioners alike. That edition was extremely successful, not only in this country, but also in many foreign countries. For a medical text, the number of copies purchased was overwhelming­ certifying that the adolescent spine is of serious interest to pediatricians, orthopaedists, physical therapists, physiatrists, medical students, and other allied health practitioners. This new edition has been revised and considerably expanded with this audience in mind. Four chapters have been contributed by authorities with special expertise.