Imaging description

There are numerous pitfalls in pediatric musculoskeletal trauma, in large part due to the progressive ossification of the maturing skeleton. Three fractures unique to pediatric imaging will be discussed here: supracondylar humeral, toddler’s type 1, and the classic metaphyseal lesion.

Supracondylar fractures are the most common pediatric elbow fractures, comprising 50–70% of such injuries [1]. These fractures are shown to greatest advantage on the lateral view, usually showing posterior angulation of the distal fragment. These are covered in detail in Case 96.

Non-displaced or hairline spiral fracture of the tibial diaphysis is referred to as toddler’s type 1 fracture, the most common subtype (Figure 99.1) [2]. Impaction or buckle fracture of the proximal tibial diaphysis, or toddler’s type 2, is a recently described but less common variant [3]. Hairline fractures may be extremely difficult or impossible to identify on standard orthogonal views. Overlying soft tissue swelling may be variably present. If suspicious for this injury, one should perform an additional oblique projection of the lower leg to optimize detection. Toddler’s fractures may manifest either as sharp oblique lucent or sclerotic lines, depending on both acuity and projection [2]. If clinical suspicion remains high and three-view tibia/fibula radiographs are negative, a scintigraphic bone scan may be performed (Figure 99.2). These exams feature a wide field of view, do not require anesthesia, and are less expensive than MRI. Bone scans may also identify tarsal fractures, particularly the cuboid and calcaneus, which may mimic tibial injuries in toddlers [4].