There has been significant progress in the field of spinal disorders in very young children over the past two decades. However, the treatment of such conditions remains challenging due to the age of the patient, different etiologies, associated morbidities and the progressive nature of the deformity. Depending on the etiology of the deformity, these children are often cared for by multiple specialists including pediatricians, pulmonologists, pediatric orthopedists or orthopedic spine surgeons, pediatric surgeons, pediatric neurosurgeons, neurologists and oncologists. Health professionals in all of the mentioned disciplines are involved in the management of these patients, which is why compiling a comprehensive text that is not limited to orthopedic specialists is essential.  Since the second edition of this book was published, there has been a significant body of literature that has been published and advances made in the care of young children with spinal and thoracic deformities. This new edition will effectively help to standardize the care of these patients. Furthermore, other professionals, such as nurses, physical therapists and healthcare professionals in training, are usually not familiar with these conditions and are in need of a reference book to consult when caring for young children with spinal deformities. Sections are arranged thematically and comprise a comprehensive presentation of the current knowledge on disorders of the growing spine. After opening sections discussing general considerations and patient evaluation and diagnosis, subsequent sections describe the various categories of spinal deformity - idiopathic, congenital, neuromuscular, syndromic, and others - followed by surgical and non-surgical management strategies, both traditional and growth-friendly. Concluding sections address patient care and outcomes and outline future directions for research and practice.