Lateral condylar fractures in children account for about 12% of elbow fractures. They result from a violent force with the elbow in extension. These fractures are unique for the risk of nonunion.
Children show swelling and pain on the lateral aspect of the elbow. Sometimes the displacement is absent or minimal, and the diagnosis is established by localized soft tissue swelling.
The fracture line may extend through the lateral condylar ossification center, between the capitellum and trochlea, or through the trochlear cartilage. Assess minor degrees of displacement in millimeters.
Type 1 Manage with a long-arm cast with the the elbow flexed to 80° and the forearm in neutral rotation. Use fiberglass or limit the amount of plaster about the elbow to facilitate radiographic assessment. Repeat an AP radiograph of the distal humerus in 2 and 3 weeks to ensure that the fracture is stable. For stable fractures, continue immobilization for 6 weeks. Should the fracture displace, reduction and pin fixation will be necessary.
Type 2 Manage fractures with displacements of 2–4 mm by closed reduction. If the fracture cannot be reduced closed to
Type 3 This type is managed by open reduction. Fix two smooth K wires or absorbable pins that securely fix the condyle and metaphysis. Leave pins protruding outside the skin to allow removal in the clinic in 4–6 weeks. Splint for comfort and to reduce irritation of pin sites.
For detailed operative reduction and pinning procedures, see next page.
Nonunion is uniquely common for this fracture, possibly because of the intraarticular position and limited blood supply. Manage based on duration. Early nonunions can be reduced and fixed like an acute fracture. Late nonunions should be stabilized to the metaphysis in situ, as they remodel and will not fit if replaced. Attempt to fuse the metaphyseal fragment of the fracture to the metaphysis. Screw fixation is optimal.
Malunion Early malunions (less than about 2 months) may be repositioned to achieve a more anatomic reduction. Leave most malunions.
Lateral Condylar Fracture Reduction
Lateral condylar fractures are unique, as they are intraarticular, involve the growth plate, and are prone to nonunion. Accept only minimal displacement of
Fractures usually extend through metaphyseal bone and with varying degrees of displacement. Displacement may be minimal or the fragment may be displaced and rotated.
Undisplaced fractures show only a linear fracture line. These fractures may be difficult to identify by conventional radiographs.
Minimal displacement fractures have 0–2 mm of displacement. Such fractures do not require reduction but do require careful follow-up, as they may be unstable and displace if the fracture line extends completely through cartilage and into the joint.
Moderate displacement fragment is separated but not rotated.
Severe displacement fragment is rotated and severely displaced.
Use supine position, tourniquet, imaging, good lighting, and small retractors.
Approach Make a lateral longitudinal incision over the distal humerus and develop the interval between the triceps and brachioradialis muscles. Drain the hematoma and identify the fracture.
Reduction Avoid removing soft tissues from the fracture fragment to preserve its blood supply. Identify the margins of the fracture and visualize the direction of displacement. Reduce the fracture anatomically with the aid of imaging. The reduction is best visualized anteriorly and by aligning the metaphyseal margins.
Fixation Fix with pins or screws. Usually two 1–2 mm smooth K wires either parallel or diverging provide adequate fixation. Leave the wires through the skin and bend the ends to prevent migration. If a metaphyseal fragment is large enough, screw fixation of this fragment to the humerus is an acceptable alternative.
Postoperative management Remove the pins in the clinic in 4–6 weeks. Maintain in a sling for 2 more weeks. Follow at 3, 6, 12 months with radiographs to assure union. Physical therapy is unnecessary.
Delayed or Nonunion
Most delayed or nonunions require operative correction to avoid progressive displacement and atrophy of the fragment and cubitus valgus.
0–12 months Reduce and fix as with an acute injury. Fixation with screws securing the metaphyseal fragment to the distal humerus often provides firm fixation.
12+ months Remodeling often causes the fragment to no longer fit, and reduction is not appropriate. Create union in situ by placing a screw across the metaphyseal fragment and humerus.