Bone Fragility Disorders in Childhood and Adolescence

There has been substantial progress in our knowledge over the last two decades about the genetic basis, natural history, and treatment of children with bone fragility disorders. Most bone fragility is due to primary and secondary osteoporotic conditions, the focus of this chapter. Important roles of the clinician are to recognize the clinical hallmarks of bone fragility conditions in children presenting for medical attention with a history of fractures and to identify and monitor at-risk children, with the goal to diagnose early (rather than late) signs of osteoporosis. Understanding a child’s ability to recover spontaneously from osteoporosis is an important component of the bone health assessment, obviating the need for bone-targeted therapy. Beyond early fracture identification and treatment, trials addressing prevention of first fractures are needed in children with both a high likelihood of fractures and, at the same time, with limited potential for medication-unassisted recovery. This chapter focuses on the evidence that has informed the current approach to diagnosis, monitoring, and treatment of childhood bone fragility disorders, with emphases on biological principles of the growing skeleton that drive the overall approach and on the clinical scenarios that practitioners face during their day-to-day care of children with fractures. This chapter also summarizes the manifestations of, and risk factors for, osteoporosis in children, the differential diagnosis and definition of pediatric osteoporosis, and recommendations for monitoring and prevention of bone fragility. Additionally, best candidates for osteoporosis therapy, recommended agents and doses, duration of therapy, how the response to osteoporosis medication is adjudicated, and side effects are also discussed. With this information, the bone health clinician will be poised to diagnose bone fragility disorders in a timely fashion, to identify which children need bone-targeted therapy, and to recognize the skeletal outcomes that gauge treatment efficacy and safety.