Supracondylar Humerus

Supracondylar humerus fractures, especially those with complete displacement, are a challenge in any setting. No remodeling of coronal angulation—varus or valgus—can be expected. However some remodeling of sagittal plane angulation will occur as the deformity lies in the plane of elbow motion. Non-angulated translation in either the coronal or sagittal plane will typically remodel. Cubitus varus, with or without hyperextension, is the most common deformity and is largely cosmetic, seldom interfering with function.

Non-displaced fractures, Type I , can be treated by a posterior splint or a long arm cast for 3 weeks, after which a removable splint or sling protects the elbow for several additional weeks.

Type II fractures have apex anterior angulation with an intact posterior cortex and greenstick deformation but no displacement. They should be reduced so that on a lateral x-ray, the anterior humeral line falls through the center of the capitellar ossification center (Fig. 27.2). The reduction is easily achieved by fully flexing the elbow. If hyperflexion is required to achieve the reduction, once the bone ends are interdigitated, immobilization at 90° will usually hold the reduction without need for continued hyperflexion. The fracture can be stabilized by percutaneous pinning or managed in a cast with close follow-up as it is stable in rotation due to the intact posterior hinge.

The goal of treating completely displaced supracondylar fractures, Type III, is to obtain an adequate functional result while avoiding complications. Ninety-five percent of Type III fractures are extension type (Fig. 27.3). The 5% flexion-type injuries are recognized by flexion of the distal fragment (Fig. 27.4) often with severe rotational deformity, seen by differing orientations of the two fragments on one x-ray. Flexion-type fractures are typically globally unstable, have no distinct periosteal hinge to assist in the reduction, and often require open reduction.

Type III fractures are unstable and if not pinned must be held in hyperflexion after reduction. This position increases the risk of vascular complications and is not recommended. If an image intensifier is available, closed reduction and percutaneous pinning can be attempted up to 5–7 days post-injury. Reduction involves applying gentle traction with the elbow in mild flexion while correcting any varus or valgus deformity. The elbow is gently and progressively flexed while applying pressure from posterior to anterior on the distal fragment and simultaneously pushing the proximal fragment of the humeral shaft from anterior to posterior. Extension fractures usually have an intact periosteal hinge posteriorly, and the reduction is locked by fully flexing the elbow. Care must be taken to ensure that the distal fragment is properly aligned with the proximal prior to fully flexing the elbow, or the periosteal hinge may be torn creating global instability. Three divergent laterally placed bicortical K-wires are sufficient fixation (Fig. 27.5).

With medial comminution or impaction, a medial K-wire can help prevent collapse into varus. It is inserted via a small incision over the medial epicondyle to avoid injury to the ulnar nerve. After placing the medial pin, flex the elbow to ensure that the ulnar nerve does not subluxate anteriorly creating impingement, as a subset of the population has positional ulnar subluxation. The extremity is placed in a posterior splint with the elbow in 60–70° flexion and the patient observed for 24 h for swelling and neurovascular function.

In some cases of Type III extension fractures, the proximal fragment is impaled through the brachialis muscle with the tip palpable under the skin. Often these show extensive bruising over the antecubital fossa (Fig. 27.6). A “milking maneuver” of the soft tissues should dislodge the fragment prior to reduction.

Flexion pattern fractures are best pinned. If an image intensifier is available, a hand table is suggested when reducing and stabilizing these unstable fractures. The fracture is first reduced in the coronal plane. With the image intensifier rotated to show a lateral projection, the elbow is extended to reduce the sagittal malalignment. In fractures that need considerable extension, one or two pins can be placed up to the fracture before extension and only advanced across the fracture after extending the elbow.

Reduction for either extension or flexion Type III injuries can be facilitated in selected cases by percutaneously introducing the blunt end of a Steinmann pin from a posterior approach and using it as a “shoehorn” to reduce the fracture (Fig. 27.7).

Options for the management of acute displaced fractures, especially in the absence of an image intensifier, include traction, closed reduction and “blind pinning,” or open reduction with percutaneous pinning. Dunlop’s side arm traction or olecranon traction can be used as a temporary measure in cases of severe swelling or as the definitive treatment (Fig. 27.8). After 2–3 weeks and callus has formed, the traction is converted to a splint or cast.

Nerve injuries are seen in up to 20% of patients with displaced supracondylar humerus fractures. The most commonly injured nerve is the anterior interosseous branch of the median nerve, tested by asking the patient to make a circle between the tips of the thumb and the index finger—an “OK” sign—that requires flexion at the two distal phalangeal joints. Radial nerve function is assessed by extending the interphalangeal joint of the thumb, and the ulnar nerve is tested by crossing the index and middle fingers.

When a nerve injury is identified at the time of presentation, the fracture is reduced and stabilized by closed or open means. In most cases the nerve will recover fully. If the fracture cannot be adequately reduced, an open exploration is suggested as the nerve or soft tissues may be trapped in the fracture. When a nerve palsy is diagnosed after the fracture is reduced in a closed manner and stabilized, nerve exploration should be considered, especially if an anatomic reduction was not achieved. A median nerve palsy may mask the pain associated with an evolving compartment syndrome.

Vascular injuries occur in approximately 5% of cases. Patients presenting with inadequate tissue perfusion—typically a pulseless and pale hand—are treated by urgent reduction of the fracture. If adequate pulse and perfusion are restored, the limb is splinted in 60–70° flexion at the elbow, and the patient is observed for 24–48 h. Exploration is required if adequate perfusion is not restored. The vessel may be entrapped within the fracture site especially if an anatomic reduction is not achieved, but more commonly the vessel is tethered to bone.

The management of the pulseless but well-perfused extremity—the pink pulseless hand—after reduction remains controversial, as there is no clear definition of “well perfused.” The vessel is often in spasm and the pulse will return with time, sometimes days later. Sometimes the patient may be relatively hypotensive while under anesthesia, and it may be reasonable to reevaluate the perfusion and pulse once the patient’s blood pressure has been restored to the normal range while waking up from anesthesia. If the pulse does not return and the perfusion is deemed adequate, many surgeons advocate close observation with frequent neurovascular checks. While the indications for immediate exploration are debated, a strong case can be made for exploration in patients with an absent Doppler and/or coexisting median nerve palsy. Pulse oximetry may assist with monitoring during the postoperative period, but this device measures skin oxygenation and not muscle perfusion, making the clinical examination of muscle function essential, especially in the diagnosis of a coexisting compartment syndrome.

Indications for an open reduction include inadequate tissue perfusion, the inability to achieve a satisfactory closed reduction, or when no image intensifier is available. An anterior approach affords direct exposure of neurovascular structures. The posterior approach may increase the risk of stiffness and triceps weakness and give no access to neurovascular structures. A medial approach is most appropriate when the proximal fragment is translated medially and/or there is an ulnar nerve injury, while the lateral approach should be considered when the proximal fragment is displaced laterally. Performing an open reduction may increase the risk of elbow stiffness and/or heterotopic ossification, especially in cases presenting after a week.

Lateral Condyle Fractures

Fractures of the lateral humeral condyle are due to a fall on the outstretched arm, with traction on the extensor origin. In contrast to a supracondylar fracture, which presents with circumferential soft tissue swelling, lateral condyle fractures have isolated swelling over the lateral elbow. When the diagnosis is in doubt, the fracture is best visualized on an internal oblique radiograph (Fig. 27.9). These fractures may be complete (extend into the joint) or incomplete (retain an intact articular cartilaginous hinge) and either non-displaced or displaced. Complete fractures which are non-displaced remain at risk for displacement, and close follow-up is required. Non-displaced fractures or those with 1–2 mm displacement can be managed in a long arm cast with the forearm in supination to relax the extensor muscles. Weekly radiographs for up to 3–4 weeks are necessary to ensure maintenance of alignment.

Some fractures are angulated, with displacement at the metaphysis but no rotation of the fragment, suggesting an intact articular cartilaginous hinge. If an image intensifier is available, an arthrogram can be useful to determine if the fracture is intra-articular. These fractures can be managed in a cast after percutaneous pinning. Fractures with complete displacement require an open reduction and fixation with 2–3 K-wires, to align the displacement at both the physis and the joint surface. The wires are removed at 3–4 weeks, and a long arm cast is applied for an additional 2–4 weeks depending on the age of the child and the degree of healing (Fig. 27.10). Healing of lateral condyle fractures is often delayed with a risk of nonunion. The torn periosteum should be repaired if possible to reduce the risk of lateral spur formation. When available, a single compression screw through the metaphyseal fragment oriented from posterolateral to anteromedial can be used. This approach may decrease the time to healing, promote earlier motion, and reduce the risks of lateral overgrowth, but a second procedure is suggested to remove the implant.