The 11 categories of musculoskeletal conditions that follow represent the most common healthcare reasons for which children and adolescents are seen in doctors' offices, emergency departments, and hospitals. Many of these conditions, such as the skeletal dysplasias, are relatively rare, diagnosed infrequently in the healthcare system, and have little data available on prevalence and burden. Though rare, they may result in significant morbidity and often require lifelong medical interventions and, therefore, warrant discussion.