old, with a peak incidence between ages and due to the relative strength of the collateral ligaments and joint capsule as compared to the bone FIGURE 111.16 Normal lateral radiograph of the elbow of a 2-year-old child The anterior fat pad is readily seen (arrow ); the posterior fat pad is not visible A line drawn along the anterior cortex of the humerus intersects the capitellum in its middle third (solid line ) A line drawn along the axis of the radius also passes through the center of the capitellum (dashed line ) Clinical assessment Supracondylar fractures commonly present with localized swelling and tenderness around the elbow on examination, with or without deformity of the distal humerus The presence of extensive swelling and ecchymosis of the elbow imparts a significant risk for compartment syndrome Any progression of increasing pain, or pain with passive extension of the fingers is concerning for ischemia and requires immediate orthopedic consultation A thorough examination of perfusion as well as motor and sensory function of the median, radial, and ulnar nerve distribution is essential ( Table 111.6 ) as nerve injuries are present in up to 15% of injuries and vascular compromise approaching 20% of injuries The median nerve—specifically the anterior interosseous branch—is the most commonly injured nerve Fortunately, most nerve injuries are temporary, resolving within to weeks after appropriate fracture reduction and immobilization FIGURE 111.17 Lateral radiograph of the elbow of a 2-year-old girl Both the anterior and posterior fat pads are elevated (small arrows ) The anterior humeral line (solid line ), passes along the anterior edge of the capitellum rather than through its center Mild buckling of the posterior cortex of the distal humerus can be seen (large arrow ) TABLE 111.5 GARTLAND CLASSIFICATION FOR SUPRACONDYLAR FRACTURES Type Description Radiographic findings Type I Nondisplaced fracture Type II Displaced fracture with intact posterior cortex Type III Completely displaced fracture with no cortical contact + posterior fat pad, “sail sign” Anterior humeral line is anterior to the capitellum, “hinged” or intact appearance of the posterior cortex Displacement of the distal fragment relative to the humeral shaft; fractures of both cortices Perfusion assessment includes: skin color and temperature, palpation of forearm compartments, capillary refill, and pulses (by palpation or Doppler if not palpable) If the child has a pink, warm hand with good capillary refill, a serious vascular injury is less likely; by contrast the child with a cold, pale hand with poor capillary refill is a surgical emergency Absence of pulses by Doppler even in the setting of good distal perfusion (e.g., “pink pulseless hand”) is an indication for emergent orthopedic consultation TABLE 111.7 GROWTH CENTERS OF ELBOW: AVERAGE AGE FOR ONSET OF OSSIFICATION Capitellum Medial epicondyle Trochlea Olecranon Lateral epicondyle 11 mo 4–6 yrs 6–8 yrs 9–10 yrs 10–12 yrs Management Fracture diagnosis requires plain radiographs of the elbow, with both anteroposterior and lateral views Comparison views of the elbow may be useful in diagnosis of fracture due to the complexity of the joint with its three points of articulation, numerous growth centers, and variable timing of ossification ( Table 111.7 ) After initial examination, patients should be splinted prior to imaging The lateral view should be with the elbow at 90 degrees of flexion to avoid a false-positive posterior fat pad sign In addition, radiographs of the forearm should be obtained, as there is a 10% to 15% risk of ipsilateral concurrent distal radius forearm fracture Interpretation of the radiographs for occult fracture requires attention to subtle changes in three regions: the fat pads (anterior and posterior), the anterior humeral line, and the radiocapitellar line In the normal lateral radiograph, the anterior fat pad is readily seen but the posterior fat pad is hidden within the olecranon fossa ( Fig 111.16 ) The presence of hemarthrosis and edema in the joint following trauma will elevate the anterior fat pad creating the “sail sign” and displace the posterior fat pad from the fossa creating a lucency posterior to the distal humerus on lateral view ( Fig 111.17 ) The presence of a posterior fat pad sign is abnormal and is 75% sensitive for the presence of an occult elbow fracture The anterior humeral line is a line drawn along the anterior cortex of the humerus and should intersect the capitellum in its middle third; however, in the presence of an extension-type injury this line will pass anteriorly Finally, a line drawn along the axis of the radius should pass through the capitellum irrespective of the degree of elbow flexion or extension on the radiograph If this is not visualized, there may be either a lateral condyle fracture or a dislocation of the radial head (as in a Monteggia fracture) ( Fig 111.18 ) ... less likely; by contrast the child with a cold, pale hand with poor capillary refill is a surgical emergency Absence of pulses by Doppler even in the setting of good distal perfusion (e.g., “pink