majority of injuries to the proximal physis are Salter–Harris types I and II In the young infant, plain radiographs may prove inadequate to evaluate the humeral head as it is primarily cartilaginous, and therefore the distinction between a fracture and a dislocation cannot easily be determined Ultrasonography or MRI may be necessary to make this diagnosis Proximal humerus fractures in skeletally immature children and adolescents are traditionally treated nonoperatively and have a tremendous capacity for remodeling As much as 50 degrees of angulation in the proximal humerus may heal without fracture reduction in the ED Nonunion and malunion are rare, except in adolescents with significantly displaced or angulated fractures Adolescents with significantly displaced fractures (greater than 20% to 50%) may be candidates for operative fixation, although data on whether this improves outcomes are limited Management is typically with a sling, sling and swathe, splint, or hanging cast for several weeks Orthopedic follow-up after discharge is recommended FIGURE 111.13 Impacted proximal right humeral fracture with approximately 25 degrees of angulation in a 3-year-old child Full remodeling can be anticipated Humeral Shaft Fractures Humeral shaft fractures are relatively rare, representing fewer than 10% of all humerus fractures in children The pattern of fracture reflects the mechanism of injury; transverse fractures result from direct blows, whereas spiral fractures are caused by twisting The thick periosteal sleeve of the humeral shaft often limits