Elbow Fracture

Elbow fractures are commonly encountered in the acute care setting. Injury patterns for children and adults are quite different. Fractures of the elbow include extra-articular and intra-articular fractures. Extra-articular fractures include intercondylar fractures, supracondylar fractures, epicondylar fractures, and condyle fractures. Intra-articular fractures include trochlea and capitellum fractures, radial head, proximal ulnar fractures. The examining physician must perform a thorough neurovascular examination with all suspected elbow fractures; recognize subtle fracture patterns; provide adequate immobilization; and assess whether fractures require admission, immediate orthopedic evaluation, or less urgent referral. ^{[1, 2, 3]}

Anatomy

The elbow is a hinge joint composed of 3 bones: the ulna, the radius, and the humerus. The 3 main articulations of the elbow are (1) the humeroradial articulation, which is formed by the radial head and the capitellum of the humerus; (2) the humeroulnar articulation, which is formed by the ulnar notch and the trochlea of the humerus; and (3) the superior radioulnar articulation, which is formed by the proximal part of the ulna and the radius. All articulations are contained in one synovial-lined capsule, which typically encases a hemarthrosis following injury.

Two main movements occur at the elbow: flexion and extension, which occurs primarily at the humeroulnar articulation, and pronation and supination, which occurs primarily at the radioulnar articulation.

Fracture patterns vary widely due to the mechanism of injury as well as the age of the patient. Direct trauma or a fall onto an outstretched hand is responsible for most elbow fractures. Neurovascular injury is a common complication of elbow fractures. The brachial artery is the most commonly injured artery and is seen especially in supracondylar fractures. The median nerve is the most commonly injured nerve, which is often is due to a displaced supracondylar humerus fracture.

Intercondylar fractures

Intercondylar fractures occur when the condylar fragments are separated. See the image below.

They are much more common in adults than in children. Any distal humerus fracture in adults is more likely intercondylar than supracondylar.

The mechanism is force directed against the posterior elbow such as a fall onto a flexed elbow, driving the olecranon against the humeral articular surface separating the condyles.

Fractures are often a T or Y shaped fracture of the distal humerus.

Treatment is often complicated and requires anatomic reduction either open or closed. ^[4]

Supracondylar fractures

The supracondylar fracture is the most common pediatric elbow fracture (60%) with the average age of 6.7 years and rarely seen after age 15 years. ^[5] See the image below.

Complications include injuries to nerves (the median, radial, and anterior interosseous nerves are the most commonly injured).

Most deficits are neurapraxias that resolve with conservative management

Motor function usually recovering in 7-12 weeks while sensory function usually recovers in 6 months. ^[6]

Vascular injuries should always be suspected with supracondylar fractures.

Ten percent of children have temporary loss of the radial pulse due to swelling and not direct arterial injury. ^[1]

The most common complication for supracondylar fractures are cubitus varus or “gunstock deformity,” which is a loss of the carrying angle and results in more of a cosmetic disability rather than a functional disability (see the image below).

Although rare (< 0.5%), the most serious complication is Volkmann ischemic contracture due to post-fracture swelling, producing increased pressure in the forearm compartment leading to muscle and nerve necrosis and eventual replacement by fibrotic tissue producing contracture. ^[7]

In general, an orthopedic consultant best handles decisions regarding reduction of significantly angulated and displaced fractures.

If neurovascular structures are compromised, the emergency physician may need to apply forearm traction to reestablish distal pulses.

If pulse is not restored with traction, emergent operative intervention for brachial artery exploration or fasciotomy is indicated.

In children, nondisplaced, nonangulated fractures can be splinted (elbow in 90° of flexion); angulated fractures require reduction and splinting; and displaced fractures (see the image below) require reduction and percutaneous pinning on an urgent basis within 12-24 hours.

In adults, supracondylar fractures generally require surgery.

Extension-type

Ninety-five percent of supracondylar fractures are of the extension-type and are displaced posteriorly due to an extension force.

• Type I fractures - Undisplaced

• Type II fractures - Displaced with posterior cortex still intact

• Type III fractures - Displaced with both anterior and posterior cortex disrupted

Management of type I fractures consists of immobilization with the elbow in flexion, while type II and II are generally treated by closed reduction followed by pin fixation.

Type III fractures have significant displacement and have a high incidence of neurovascular injury and therefore require urgent orthopedic consultation in the ED.

Open reduction is reserved for vascular insufficiency with a probable entrapped brachial artery in the fracture site or an irreducible fracture.

Flexion-type

Five percent of supracondylar fractures are of the flexion-type and have anterior displacement due to a flexion force.

The mechanism usually involves direct anterior force with anterior displacement of the distal fragment.

Open fractures are relatively common due to the direct force.

• Type I fractures - Undisplaced

• Type II fractures - Displaced with anterior cortex still intact

• Type III fractures - Displaced with both anterior and posterior cortex disrupted and distal fragment migrants anteriorly and proximately

Treatment of type I fractures is simple immobilization in the flexed position.

Treatment of type II and III fractures should be referred to an orthopedist emergently and is often reduced to an extension position and requires surgical management. ^[1]

Medial epicondyle fracture

Fractures of the epicondyles are considered extra-articular.

Medial epicondyle fractures are usually in children as an avulsion type injury (see the image below).

Mechanisms include posterior elbow dislocation, throwing a baseball (Little League elbow), or a direct blow.

Edema and pain over the medial elbow is common.

Nondisplaced or minimally displaced medial epicondyle fractures are treated nonoperatively.

Fragment displacement greater than 1 cm or valgus instability is often treated with internal fixation.

Rarely, entrapment of the medial epicondyle can occur between the trochlea and the coronoid process of the ulna; this can be mistaken for the ossification center of the trochlea.

ED management consists of immobilization of the forearm in flexion and pronation and the wrist in flexion.

Lateral epicondyle fracture

Lateral epicondyle fracture is very rare and is usually due to an avulsion fracture.

Fracture of the lateral humeral epicondyle can be mistaken for the radiolucency of the epiphysis. ^[8]

Treatment is immobilization with the elbow flexed to 90 degrees and the forearm in supination. ^[8]

Medial condyle fracture

Medial condyle fracture is rare and is usually found in children.

The mechanism is a fall on outstretched hand or excessive valgus stress.

This injury is often confused with medial epicondyle fractures.

Minimally displaced fractures are usually casted, whereas fractures with greater displacement usually require open or closed reduction with pin fixation. ^[8]

Lateral condyle fracture

Lateral condyle fracture is usually found in children and is the second most common pediatric elbow fracture. ^[9] See the image below.

The mechanism is a blow to the lateral elbow or from varus stress.

Minimally displaced fractures are usually casted, whereas fractures with greater displacement usually require open or closed reduction with pin fixation. ^[9]

Trochlea fracture

Isolated trochlea fractures are rare and are usually associated with other elbow injuries.

Nondisplaced fractures are usually managed with a posterior splint, whereas displaced fractures require surgical management. ^[8]

Capitellum fracture

Isolated capitellum fractures are rare as they often occur in posterior elbow dislocations or with radial head fractures.

They are usually due to a fall on an outstretched hand.

Surgical repair is often indicated.

Radial head fractures

Radial head fracture is the most common of all fractures of the elbow and associated injuries are common. See the image below.

The mechanism is usually a fall onto an outstretched hand.

Radial head fracture is characterized by point tenderness at the radial head (located along the lateral aspect of the elbow) and pain with pronation/supination.

A specific associated injury, the Essex-Lopresti lesion occurs when the radial-ulnar interosseous membrane is disrupted, causing distal radioulnar joint dissociation.

Careful examination of radiographs is important because fractures may be subtle.

For nondisplaced fractures, a sling with the elbow in flexion is usually adequate.

With displaced radial head fractures, patients can be placed in a posterior long-arm splint with the elbow in 90° of flexion and the forearm in full supination and placed in a sling for comfort.

Olecranon fractures

The mechanism is usually a direct blow or a fall onto an outstretched hand. See the image below.

The fracture line is usually transverse, passing into the trochlear notch. ^[8]

Patients demonstrate an inability to extend the elbow actively, along with point tenderness at the olecranon.

Ulnar nerve injury is common.

Patients can be placed in a well-padded, long-arm posterior splint with the elbow in 70° of flexion and the forearm neutral with respect to pronation/supination.

Nondisplaced fractures are usually managed conservatively, whereas all others often require surgical repair.

Age

Fracture patterns vary markedly among different age groups.

Supracondylar fractures are the most common elbow fracture in children because of the relative strength of surrounding ligaments in comparison to bone.

Radial head fractures are the most common elbow fracture in adults.