Elbow Dislocation in Emergency Medicine

Background

The elbow joint displays an elegant balance between stability and mobility. While allowing a wide range of motion, the joint has an inherent stability that requires a considerable force to dislocate. As a result, a significant percentage—approximately one third of elbow dislocations—are associated with fractures of bony components of the elbow. Dislocations without associated fracture are termed simple, while dislocations with accompanying fracture are termed complex.

Dislocations of the elbow fall in frequency just behind dislocations of the finger and shoulder. Most commonly, the elbow dislocates posteriorly. Immediate reduction is essential to reduce the risk of neurovascular or cartilaginous complications.

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Anteroposterior radiograph of the elbow demonstrates the normal anatomy.

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Lateral radiograph of the elbow demonstrates the normal anatomy.

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Pathophysiology

Both posterior dislocations and anterior dislocations can occur.

Posterior dislocations

A fall onto an extended abducted arm is the mechanism of injury seen in posterior dislocations of the elbow. An example of this is someone rollerblading who, falling backward, extends an arm behind to break the fall. Posterior dislocations account for most elbow dislocations. Closed posterior dislocations are not commonly associated with neurovascular injury.

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Lateral view of the elbow demonstrates a posterior dislocation of the elbow. The patient also had a nondisplaced radial head fracture.

Anterior dislocations

A strong blow to the posterior aspect of a flexed elbow may result in anterior dislocation of the elbow. This force drives the olecranon forward in relation to the humerus. Anterior dislocations and any open fracture are commonly associated with disruption of the brachial artery and/or injury to the median nerve.

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Epidemiology

Elbow dislocation injuries occur more often in males than in females. Dislocations occur more commonly in adults, since the same force in children more often results in a supracondylar fracture of the distal humerus.

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Prognosis

Up to 10 degrees limitation in full extension and some limitation in flexion are common, unless an intensive rehabilitation program is instituted.

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Patient Education

For patient education resources, see the Breaks, Fractures, and Dislocations Center, as well as Elbow Dislocation and Broken Elbow.

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History

Obtain history that includes the mechanism of injury, type and location of pain, amount of immediate dysfunction, treatment prior to arrival in the emergency department, timing of effusion appearance, and history of prior elbow injury.

• Mechanisms - A fall onto an extended, abducted arm (posterior) or a direct blow to a flexed elbow (anterior)
• Pain - Intense, focused around the elbow joint
• Extremely limited range of motion
• Effusion

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Physical

In posterior dislocations, the elbow is flexed, with an exaggerated prominence of the olecranon. On palpation, the olecranon is displaced from the plane of the epicondyles (as opposed to a supracondylar fracture, in which the epicondyles are palpable in the same plane as the olecranon).

In anterior dislocations, the elbow is held in full extension. The upper arm appears shortened, while the forearm is elongated and held in supination.

Neurovascular function should be documented in detail before and after reduction. Continued repeated examination is essential.

Indications for admission with frequent neurovascular assessment include the following:

• Children
• Unreliable patients
• Extensive edema
• Evidence of neurovascular compromise either before or after reduction

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Complications

Complications of elbow dislocation may include the following:

• Brachial artery injury^[1]
• Medial nerve injury
• Ulnar nerve injury
• Concomitant fractures
• Avulsion of the triceps mechanism insertion (anterior dislocation only)
• Entrapment of bone fragments within the joint space
• Joint stiffness with decreased range of motion (particularly in extension)
• Myositis ossificans
• Compartment syndrome

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Imaging Studies

Plain radiographs are essential prior to reduction of the suspected dislocation. Postreduction films should confirm opposition of the joint surfaces and should rule out previously unidentified fractures or entrapment of bony fragments within the joint space.^[2]

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Other Tests

Arteriography should be performed for cases of suspected vascular injury.

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Prehospital Care

Prehospital personnel should splint the limb in the position found. Because of the risk of neurovascular injury, field reduction is not recommended. Successful reduction is usually unsuccessful without adequate analgesia and sedation. Patients with neurovascular compromise should be transported rapidly to the closest facility.

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Emergency Department Care

Early reduction is essential, since delay may increase the risk of neurovascular compromise or damage to articular cartilage.^[3]  The emergency physician should attempt reduction after obtaining appropriate radiologic studies if evidence of vascular compromise is noted or if orthopedic consultation is delayed significantly.^{[4, 5, 6]}

The following 2 methods commonly are used for posterior elbow reductions. Be certain that the patient has received adequate analgesic and sedative medications before beginning either procedure. Also see, Joint Reduction, Elbow Dislocation, Posterior.

• With the elbow flexed to 90 degrees and supinated, apply posterior pressure to the humerus while a second operator applies downward pressure on the proximal forearm. A coupling is felt and heard as the capitellum slides over the coronoid process and the joint realigns.
• The second method (the Parvin method) involves placing the patient in the prone position with the humerus resting on the table and the forearm hanging perpendicular to the plane of the table. The humerus should be supported by the table, with padding, just proximal to the elbow joint. Apply 5-10 lb of weight to the wrist or gently pull down at the wrist. Reduction should occur over a period of minutes as the muscles relax. The physician may guide the olecranon into place if necessary.

Anterior dislocation reduction is performed with distal traction on the wrist and backward pressure on the forearm. Take care to avoid hyperextension at the elbow, which may cause traction and potential injury to neurovascular structures around the elbow.

Postreduction neurovascular check should always be performed as the brachial artery and the median and ulnar nerves can become entrapped with manipulation.

A failed closed reduction is indicative of an entrapped medial epicondyle or an inverted cartilaginous flap. Reed et al cite a case of acute ulnar nerve entrapment after closed reduction.^[7]

Patients with dislocations of the elbow should not be transferred until the elbow has been reduced. In hospitals without access to an orthopedic surgeon, reduction should be performed by the emergency physician prior to transfer.

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Consultations

Emergent orthopedic consultation should be sought for all patients with elbow dislocations. Vascular surgery consultation may be needed in patients with possible vascular injury.

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Complications

Following reduction, splint elbow in at least 90 degrees of flexion using a posterior molded splint. Arrange close follow-up care with the orthopedic surgeon. In a self-reported study of patients sustaining simple elbow dislocations, despite a good long-term functional prognosis, there was a relatively high rate of residual pain and elbow stiffness. Therefore, it is important for patients to receive timely outpatient follow-up with an orthopedic specialist.^[8]

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Medication Summary

Analgesics and anxiolytics are used to treat the pain associated with dislocations.

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Fentanyl citrate (Duragesic, Sublimaze)

• Dosing, Interactions, etc.

Clinical Context:  Narcotic analgesic with more potency and much shorter half-life than morphine sulfate. DOC for conscious sedation analgesia. With short duration (30-60 min) and ease of titration, an excellent choice for pain management and sedation. Easily and quickly reversed by naloxone. After initial dose, subsequent doses should not be titrated more frequently than q3h or q6h.

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Oxycodone and acetaminophen (Percocet)

• Dosing, Interactions, etc.

Clinical Context:  Drug combination indicated for relief of moderately severe to severe pain. DOC for aspirin-hypersensitive patients.

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Oxycodone and aspirin (Percodan)

• Dosing, Interactions, etc.

Clinical Context:  Drug combination indicated for relief of moderately severe to severe pain.

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Hydrocodone bitartrate and acetaminophen (Vicodin ES)

• Dosing, Interactions, etc.

Clinical Context:  Drug combination indicated for relief of moderately severe to severe pain.

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Morphine sulfate (MS Contin, MSIR)

• Dosing, Interactions, etc.

Clinical Context:  DOC for analgesia due to reliable and predictable effects, safety profile, and ease of reversibility with naloxone.

Various IV doses are used; commonly titrated until desired effect obtained.

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Class Summary

Pain control is essential to quality patient care. It ensures patient comfort, promotes pulmonary toilet, and aids physical therapy regimens. Many analgesics have sedating properties that benefit patients who have sustained injuries.

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Diazepam (Valium)

• Dosing, Interactions, etc.

Clinical Context:  Individualize dosage and increase cautiously to avoid adverse effects. By increasing activity of GABA, a major inhibitory neurotransmitter, depresses all levels of CNS, including limbic and reticular formation.

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Lorazepam (Ativan)

• Dosing, Interactions, etc.

Clinical Context:  Sedative hypnotic in benzodiazepine class with short onset of effect and relatively long half-life. By increasing activity of GABA, a major inhibitory neurotransmitter, may depress all levels of CNS, including limbic and reticular formation. Excellent medication when patient needs to be sedated for >1 d. Monitor patient's BP after administering dose and adjust as necessary.

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Class Summary

Patients with painful injuries usually experience significant anxiety. Anxiolytics allow the clinician to administer a smaller analgesic dose to achieve the same effect.

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