Ninety-five percent of bone tumors are now managed with limb-sparing techniques. For pediatric patients with bone cancer, such limb reconstruction techniques often involve the placement of large endoprosthetic devices with the goal of improving survivors' quality of life. Nevertheless, few radiologic publications discuss the use of these techniques in children and adolescents. This pictorial essay describes the imaging characteristics of the complications associated with endoprosthetic devices and discusses the conditions that may simulate them.