The chapter begins with the discussion of spondylolysis and spondylolisthesis, including a section describing various methods for imaging these conditions. Intervertebral disc disease follows, with discussion of intervertebral calcifi cation and disc prolapse. Spinal trauma is addressed, along with infl ammatory and neoplastic destructive vertebral lesions. The last section of the chapter covers salient features of tumors that occur in the spine, including osteoid osteoma, osteoblastoma, aneurysmal bone cyst, Langerhans cell histiocytosis, and osteochondroma.The pediatric spine is affected by a variety of processes that are unique to children or that manifest in children in unusual ways. Spondylolysis represents a response to chronic stress injury and may lead to spondylolisthesis, wherein one vertebra slips forward on the subjacent vertebra. Spine fractures in young children differ greatly from those in adults and are especially common in the upper cervical spine. Discitis, an uncommon idiopathic infl ammatory process, is essentially limited to children, whereas disc herniation and spine infection in children resemble these processes in adults. Several bone tumors, such as osteoid osteoma/osteoblastoma, Langerhans cell histiocytosis, and osteochondroma have unique appearances in the spine. (Infl ammatory,