Elbow Dislocation Management in the ED

Simply put, the elbow is the articulation between the distal humerus and the proximal ulna and radius. The distal humerus contains the trochlea medially and the capitulum laterally. The elbow comprises 3 separate articulations. The medial aspect of the elbow includes the ulnotrochlear joint, which is primarily responsible for flexion and extension. The lateral radiocapitellar joint and the proximal radioulnar joint are mainly responsible for pronation and supination. This anatomy creates a combination of a hinge joint and a pivot joint.[1]

The elbow is generally stable due to the congruity of articular surfaces. It is further supported by static supporting structures, including the collateral ligaments on the medial and lateral side of the elbow and the joint capsule. Dynamic stabilizers of the joint are composed of the surrounding musculature.[1]  

The vascular anatomy of the elbow is composed of a few structures. The brachial artery is a central component of the anterior elbow and eventually divides into the radial and ulnar arteries in the proximal forearm. The radial and ulnar arteries, along with the brachial and deep brachial arteries, create an intricate anastomosis of vessels around the elbow, including radial and ulnar collateral arteries and radial and ulnar recurrent arteries.[1]

Many nerves are present around the elbow, whose function can be compromised by an elbow dislocation.[1]

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 dislocation of the elbow. Posterior dislocations account for most elbow dislocations. Closed posterior dislocations are not commonly associated with neurovascular injury.

These injuries frequently occur during sporting activities when a person falls on an extended elbow. In most instances, the semilunar notch of the ulna is dislocated posteriorly from the distal humerus. If no fracture is associated with the dislocation, it is described as simple and the injury is often closed with no bony protrusion through the skin.[5]

The stability of the elbow joint due to its bony structure means that significant force is required to disrupt the joint. Therefore, an associated fracture may be found along with the elbow dislocation, thus classifying the dislocation as complex. Neurovascular complications following a simple, closed, posterior dislocation are rare.[5]  

(The radiograph below shows a posterior dislocation of the elbow.)

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 fractures are commonly associated with disruption of the brachial artery and/or injury to the median nerve.

The less often encountered anterior elbow dislocation requires much more force, and concern for neurovascular compromise should be greater.[5]

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

The elbow is the second most commonly dislocated major joint in adults.[4]  However, anterior elbow dislocation is a rare injury in both adults and children.[2]

Outcomes and treatment satisfaction following simple elbow dislocation generally are good but are significantly worse for patients with greater levels of social deprivation and for those receiving Workers’ Compensation or Medicare insurance. Although surgeons should be aware that specific subsets of patients may benefit from early therapy, a longitudinal cohort study found that this factor did not appear to influence long-term outcomes.[7]

Obtain patient history that includes mechanism of injury, type and location of pain, amount of immediate dysfunction, treatment prior to arrival in the ED, timing of the appearance of effusion, 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 at the elbow joint

• Dysfunction: Extremely limited range of motion

• Effusion: Posterior fat pad displaced dorsally and superiorly by joint fluid

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, and the forearm is elongated and is 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:

• Pediatric patients
• Unreliable patients
• Presence of extensive edema
• Evidence of neurovascular compromise before or after reduction

Complications of elbow dislocation may include the following:

• Brachial artery injury[8]

• 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

Treatment of complex elbow dislocation fractures is a challenge for both the treating surgeon and the patient because of the complex bony and soft tissue anatomy of the joint. To establish an expedient treatment algorithm, the clinician must thoroughly assess all osseous and ligamentous injuries.[9]   

Unnecessary delay in treatment of this complex injury can result in posttraumatic functional disorders, recurrent instability, and secondary arthrosis. Goals of surgical treatment must include correct restoration of joint anatomy and stability as prerequisites for successful treatment of elbow fracture/dislocation to enable early motion of the joint.[9]  

Plain radiographs are essential prior to reduction of a suspected dislocation. Postreduction films should confirm opposition of joint surfaces and should rule out previously unidentified fractures and entrapment of bony fragments within the joint space.[10]

A descriptive series undertaken to retrospectively analyze and describe patterns of ligamentous, tendinous, and muscular injuries in patients with acute elbow dislocation and subsequent MRI evaluation reported that injuries to the ulnar collateral ligament were most common. Although ligamentous injuries are exceedingly common in elbow dislocation, large studies of MRI findings have proved difficult because of the costs of MRI.[11]

Arteriography should be performed for cases of suspected vascular injury.

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

Early reduction is essential because delay may increase the risk of neurovascular compromise or damage to articular cartilage.[12]  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.[13, 14, 15]

Two methods are commonly used for posterior elbow reduction. Be certain that the patient has received adequate analgesic and sedative medications before beginning either procedure:

• With the elbow flexed to 90º 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 OR
• Use the Parvin method: Place 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. Perform reduction over a period of minutes as the muscles relax. 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.

Failed closed reduction is indicative of an entrapped medial epicondyle or an inverted cartilaginous flap. Reed et al have described a case of acute ulnar nerve entrapment after closed reduction.[16]

Patients with dislocation 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.

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

Following reduction, splint the elbow in at least 90º 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 dislocation, despite a good long-term functional prognosis, a relatively high rate of residual pain and elbow stiffness was reported. Therefore, it is important for patients to receive timely outpatient follow-up with an orthopedic specialist.[17]

Analgesics and anxiolytics are used to manage the pain associated with dislocation.

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.

Fentanyl citrate (Duragesic, Sublimaze)

Narcotic analgesic with greater potency and a much shorter half-life than morphine sulfate. Drug of choice (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.

Oxycodone and acetaminophen (Percocet)

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

Oxycodone and aspirin (Percodan)

Drug combination indicated for relief of moderately severe to severe pain.

Hydrocodone bitartrate and acetaminophen (Vicodin ES)

Drug combination indicated for relief of moderately severe to severe pain.

Morphine sulfate (MS Contin, MSIR)

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

Various IV doses are used and are commonly titrated until desired effects are obtained.

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.

Diazepam (Valium)

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.

Lorazepam (Ativan)

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 day. Monitor patient's BP after administering dose, and adjust as necessary.