Cutting edge Orthopedics

Supracondylar Humerus Fractures • 11  contralateral limb may be used for comparison, if needed. Repeat exams may be necessary to ensure that a complete exam is obtained [9]. Palpation All bony prominences of the limb should be palpated. During the assessment, the child’s face should be observed for grimaces, withdrawal, or other signs of discomfort, as some children may have difficulty verbalizing their pain [9]. It is best to begin palpating in areas that are not expected to elicit pain, such as the shoulder or hand, and work toward the injured region. About the elbow, careful evaluation of the tender regions may help narrow the differential diagnosis. Tenderness just proximal to the elbow joint on both the medial and lateral sides suggests a supracondylar humerus fracture, whereas tenderness at or just proximal to the joint line on the lateral side raises suspicion for a lateral condyle fracture, tenderness on the posterior aspect of the elbow is sugges- tive of an olecranon fracture, and tenderness distal to the joint line on the lateral side suggests a radial head or neck injury [9]. Additionally, compartments should be assessed for fullness, com- pressibility, and pain with palpation. Changes in pain with passive movement of the wrist and fingers should be noted. Radiographic Evaluation Radiographic imaging of the entire upper extremity is often warranted for children with elbow injuries [9, 34] unless a reliable clinical exam can sufficiently rule out associated injuries. The elbow is best assessed with an anteroposterior (AP) view of the distal humerus (rather than the elbow) and a true lateral view of the elbow [5, 8, 9]. The images are inspected for fracture dis- placement, angulation, rotation, translation, comminution, and intra-articular extension [9]. The lateral view is particularly useful for assessing children with suspected supracondylar humerus fractures as the AP view may appear normal [9]. The patient’s skeletal maturity, i.e., presence or absence of secondary ossification centers and/or physeal lines, should be considered when review- ing radiographs, and contralateral films may be obtained for comparison as needed. Subtle, nondisplaced fractures may occur. The lateral radiograph should be scrutinized for lucency along the posterior border of the humerus at the olecranon fossa. Observation of this lucency, known as a posterior fat pad sign, raises suspicion for the presence of a fracture (Fig. 2). It occurs when fat is displaced posteriorly out of the olecranon fossa due to an intracapsular effu- sion, which can occur with bleeding from the fracture site in the setting of trauma. A previous study investigating the final diagnosis for pediatric elbow radiographs that were negative except for a posterior fat pad sign determined that 76% had an occult fracture about the elbow. Of the 76% that had a fracture, 53% were a supracondylar humerus fracture [44]. Notably, the anterior fat pad can be visualized on normal elbow radiographs [45] and is not a reliable predictor of fracture [9]. There are several radiographic parameters that should be evaluated when a supracondylar humerus fracture is present. In a typical elbow, the anterior humeral line, a line following the