Transient fatty cortical defects following fractures in children.

Self-regressing subperiosteal defects appearing during consolidation of fractures were observed in two children aged 6 and 10 years, in the tibia and the radius respectively. These transient defects appeared several weeks after fracture, at a distance from the fracture site. They involved the newly formed subperiosteal bone, did not enlarge, and were replaced progressively by normal-appearing bone. A computed tomography (CT) study performed on one of these defects demonstrated a density consistent with a fatty content. It is suggested that these transient post-traumatic defects could result from the inclusion of medullary fat drops within the subperiosteal hematoma near the fracture site.