Reduction and Fixation of Lateral Condyle Fractures of the Distal Humerus

Neeraj M. Patel, MD, MPH, MBS

John M. Flynn, MD

Dr. Flynn or an immediate family member has received royalties from Biomet and serves as a board member, owner, officer, or committee member of the American Board of Orthopaedic Surgery, Inc. Neither Dr. Patel nor any immediate family member has received anything of value from or has stock or stock options held in a commercial company or institution related directly or indirectly to the subject of this chapter.

PATIENT SELECTION

Fractures of the lateral condyle of the humerus typically occur as a result of a fall, either on an outstretched hand or from a height. Classically, these injuries are categorized as Milch type I fractures if they pass through the ossific nucleus of the capitellum or Milch type II fractures if they pass medial to the capitellum and into the trochlear groove.¹ However, treatment decisions are typically more dependent on the extent of displacement than on location² (Figure 1).

Nonsurgical treatment with a long arm cast is adequate for nondisplaced or minimally displaced fractures (<2 mm). Surgery is recommended for fractures with greater than 2 mm of displacement or fragment rotation. Closed reduction with percutaneous pinning may be appropriate for minimally displaced fractures (2-4 mm) when a perfect intra-articular reduction can be obtained. Open reduction and internal fixation is recommended for fractures that are unstable or significantly displaced (>4 mm). Although these are useful guidelines, closed reduction may be acceptable for significantly displaced fractures when performed by an experienced surgeon and if perfect articular congruity is confirmed with arthrography.³^,⁴

PREOPERATIVE IMAGING

When a lateral condyle fracture is suspected, AP, lateral, and internal oblique radiographs should be obtained (Figure 2). The oblique view is particularly valuable in determining maximum displacement and for following the fracture after closed or open treatment. Careful examination of multiple radiographic views is necessary to assess any potential rotational displacement. Of note, the size of the fracture fragment is typically larger than is visualized on plain radiographs because of its cartilaginous component. Hinging of the condylar fragment into the joint space might be difficult to determine radiographically for some minimally displaced fractures. In such situations, MRI or magnetic resonance arthrography can be considered to assess for disruption of the articular surface. However, treatment decisions can typically be made with radiographs, so these other modalities are not commonly used because of their cost and because they frequently require patient sedation.

PROCEDURE

Special Instruments/Equipment/Implants

A fluoroscopic unit is used for intraoperative imaging. A tourniquet is valuable for creating a bloodless field,
improving visualization, and assessing joint surface congruity (Figure 3, A). A pin driver is required to place pins, typically 0.062-in Kirschner wires (K-wires). For open reduction, a small right-angle retractor and a towel clip are helpful (Figure 3, B). Alternatively, a compression screw can be used in an older child with a large, bony condylar fragment. A splint or cast is necessary for postoperative immobilization.

FIGURE 1 Illustrations show the Jakob classification of lateral condyle fractures. A, Type I: displaced less than 2 mm with no violation of the articular surface. B, Type II: displaced 2 mm or more with no violation of the articular surface. C, Type III: displaced 2 mm or more with disruption of the articular surface.

FIGURE 2 AP (A) and lateral (B) radiographs show a lateral condyle fracture in the right arm of a 5-year-old patient.

FIGURE 3 Photographs show patient positioning and equipment for open reduction and internal fixation of a lateral condyle fracture. A, The arm is shown on a hand table and with a tourniquet in place. B, A small right-angle retractor; this may be used to raise anterior soft tissues.