PEDIATRIC SKELETAL TRAUMA
Pediatric bones are softer than adult bones as they are more porous and less well mineralized. There are distinct anatomic differences between the pediatric and adult bone, and a nomenclature has evolved to identify the fractures and the different regions of the pediatric bone affected (Figure 5-1). Pediatric bones demonstrate a physis or growth plate, seen as a lucency between the flared metaphyseal region of the bone and the growth center or epiphysis. The shaft is called the diaphysis. Pediatric bones grow in length through endochondral ossification at the metaphyseal edge. The bone also grows in width across the diaphyseal aspect of the bone though membranous ossification. Healing of fractures in pediatric patients is more rapid than seen in adults.
Normal forearm. Normal frontal radiograph of pediatric forearm. Arrowheads show physes (growth plates). Asterisks denote epiphyses, (M) shows metaphyseal region, and (D) diaphyseal region.
The fracture patterns seen with pediatric trauma are unique to this patient population. Three common fracture types are the plastic deformity, the “buckle” or torus fracture, and the greenstick fracture. The plastic deformity is a bone that has bent without a visible fracture line. There are likely microscopic fractures on the concave or compression side of the injury.1 These types of fractures are often seen in the forearm or lower leg where two bones are present (Figure 5-2). The ulna and fibula are commonly affected, and there may be a complete fracture of the other paired long bone. Radiographic findings may be so subtle that it is not unusual to see the fracture deformity only after callus formation is identified.
Plastic fracture of ulna. Frontal forearm radiograph shows plastic deformity (bowing) of the ulna with excessive radial curvature of the shaft (arrow). Incident note made of midshaft radial fracture.
Buckle or torus fractures usually occur in the metaphyseal region of the bone, and they appear as small bumps on an otherwise smooth cortex. There is compression of the bone in this region. A careful search of all of the standard radiographic series is warranted, as the buckle may only be seen in one projection. Therefore, the fractures may be missed with one “spot” view done in the emergency room setting. The most frequent location is in the metaphyseal region of the dorsal cortex of the distal radius and ulna. Both bones may be affected (Figure 5-3).
Buckle (torus) fractures. Frontal wrist radiograph shows small buckle fractures in both ulnar (arrowhead) and radial (arrow) cortices.
A greenstick fracture is a unicortical fracture, with only the bent or tension side ...