Development and duration of radiographic signs of bone healing in children.

OBJECTIVE Few articles report the evaluation of pediatric fracture healing and dating based on radiographic appearance. We established a timetable for expected radiographic changes visible during bone healing in otherwise healthy children. MATERIALS AND METHODS We examined 707 radiographs of fractured forearms in 141 patients. Each fracture was assessed by a pediatric radiologist who was unaware of the timing of the initial injury. Assessment included the following features: fracture margins, fracture gap, periosteal reaction, callus, bridging, and remodeling. The time interval between injury and the appearance of the radiographic features and the duration of radiographic signs were determined and correlated with age, sex, angulation, displacement, and location. RESULTS Sclerosis at the fracture margins was evident in 85% of fractures 5 weeks after injury. Widening of the fracture gap was observed in 62% of fractures at 6 weeks. Periosteal reaction was evident on all images by 4 weeks, and after 7 weeks, periosteal reaction was separable from cortex in only 10% of fractures. Fracture callus had a density equal to or greater than that of adjacent cortex 10 weeks after injury in 90% of fractures. CONCLUSION A wide variation exists in the appearance and duration of the radiographic signs of bone healing. Marginal sclerosis should be an expected radiographic sign of normal bone healing. Applying maximum and minimum time spans to objective radiographic signs may aid in fracture dating.