Cutting edge Orthopedics

Supracondylar Humerus Fractures • 17  the elbow is then utilized to confirm anatomic sagittal alignment with the anterior humeral line intersecting the middle third of the capitellum [5, 8, 9, 19]. In children under age 4, the anterior humeral line may intersect either the middle or anterior third of the capitellum [46], and a con- tralateral radiograph should be considered for comparison. Alternatively, one can perform an arthrogram to visualize the articular surface. Oblique views should also be used to confirm that the medial and lateral columns are intact [5, 8, 19]. If an anatomic reduction is difficult and a “rubbery” sensation is appreciated during frac- ture manipulation, rather than crepitance, one should consider entrapment of the neurovascular structures at the fracture site [5, 9, 19, 30]. The median nerve and/or brachial artery may become trapped in the fracture site. When this occurs, the surgeon should proceed to an open reduction [5, 9, 19]. After clinically and radiographically confirming an anatomic reduction in all planes, the frac- ture should be stabilized with percutaneously placed pins. Typically, 0.062 inch smooth Kirschner wires [8, 9] or 2.0 mm smooth Steinmann pins (both commonly referred to as “pins”) are utilized [9]. A small bump may be placed under the elbow to facilitate access to the distal humerus during pinning [9]. The “shoot-through” Jones view is used to assist with K-wire placement, while the surgeon continues to hold the reduction with the elbow in hyperflexion. If no skilled assistant is available to place the pins, the forearm and upper arm may be taped together circumferentially (Fig. 14) [9]. Of note, once the elbow is maintained in hyperflexion, local ischemia occurs [9]. The capitellum and lateral epicondyle of the humerus are palpated, and the first pin is placed through the skin and soft tissue down to the bone. The Jones view and lateral radiographs are used to confirm the proper pin starting point and trajectory. The pin should be directed through the lateral cortex of the distal fragment, across the fracture, and then advanced through the medial cortex in the proximal segment [9]. Care should be taken not to advance the pin too far into the soft tissue; however, the entire conical portion of the pin tip should be positioned beyond the far cortex to achieve bicortical fixation. There are no known complications related to a pin passing Fig. 13: The posterior aspects of the olecranon ( top ) and medial and lateral epicondyles should form an isosceles triangle (Courtesy of Stephanie A. Russo, MD). 49 is obtained, the elbow should be stabilized and maintained in the hyperflexed positon, while the upper arm is externally rotat d at gl nohumer l joint (Video 4.2). This facil- itates performan e of a lateral radiograph without displaci g the fracture. If the fracture appears to be specially unstable, one should consider rotating the C-arm rather than the patient’s arm. A lateral view of the elbow is then utilized to confirm anatomic sagittal alignment with the anterior humeral line inter- secting the middle third of the capitellum [ 5 , 8 , 9 , 19 ]. In children under age 4, the anterior humeral line may intersect either the middle or anterior third of the capitellum [ 46 ], and a contralateral radiograph should be considered for comparison. Alter ativ ly, one can per- form an arthrogram t visualize the articul r surface. Oblique views should also be used to confirm that the medial and lateral colum s are intact [ 5 , 8 , 19 ]. If an anatomic reduction is difficult and a “rubbery” sensation is appreciated during fracture manipulation, rather than crepitance, one should consider entrapment of the neurovascular struc- tures at the fracture site [ 5 , 9 , 19 , 30 ]. The median nerve and/or brachial artery may become trapped in the fracture site. When this occurs, the surgeon should pro ee to an pen eduction [ 5 , 9 , 19 ]. After clinically and radiographically confirm- ing an anatomic reduction in all planes, the frac- ture should be stabilized with percutaneously placed pins. Typically, 0.062 inch smooth Kirschner wires [ 8 , 9 ] or 2.0 mm smooth Steinman pins (both commonly referred to as “pins”) are utilized [ 9 ]. A small bump may be placed under the elbow to facilitate access to the distal humerus during pinning [ 9 ]. The “shoot- through” Jones view is used to assist with K-wire placement, while the surgeon continues to hold the reduction with the elbow in hyperflexion. If no skilled assistant is available to place the pins, the forearm and upper arm may be taped together circumferentially (Fig. 4.14 ) [ 9 ]. Of note, once the elbow is maintained in hyperflexion, local ischemia occurs [ 9 ]. The capitellum and lateral epicondyle of the humerus are palpated, and the first pin is placed through the skin and soft tissue down to the bone. The Jones view and lateral radiograph are u ed to onfirm the proper pin starti g point and trajectory. The pin hould be directed through the lateral cortex of the distal fragment, across the fracture, and then advanced through the medial cortex in the proximal seg- ment [ 9 ]. Care should be taken not to advance the pin too far into the soft tissue; however, the entire conical portion of the pin tip should be positioned beyond the far cortex to achieve bicortical fixa- tion. There are no known complications related to a pin passing through the olecranon fossa, and it is thought to potentially improve stability by adding two additional corti es to the fixation [ 8 , 9 ]. After th first pin is uccessfully placed, the same steps ar repeated for the second pin. The tw pins shoul diverge across the fracture in both the AP and lateral planes. The pins should be as far from each other as possible as they tra- verse the fracture site [ 9 , 19 ] (Fig. 4.15 ). Generally, two pins are placed for Type II fractures and three pins for Type III fractures [ 8 , 9 , 14 , 19 , 61 ]. However, in all cases, the fracture should be stressed under live fluoroscopy Fig. 4.13 The posterior aspects of the olecranon ( top ) and medial and lateral epicondyles should form an isosce- les triangle (Courtesy of Stephanie A. Russo, MD) 4 Supracondylar Humerus Fractures