Chapter 82. Elbow Joint Dislocation Reduction

The elbow is inherently subjected to dislocations because of its mechanical structure.1 Elbow dislocations are one of the more common joint dislocations in the body, second only to dislocations of the shoulders and fingers.2 Injuries to the elbow have a high potential for complications and residual disability.3 Timely reduction is imperative to relieve pain and reduce the possibility of neurovascular sequelae.3 Closed reduction of the elbow is unlikely to be successful if not performed promptly.4

The most common mechanism for a dislocation is a fall onto an extended and abducted arm. The patient usually presents with a swollen and painful arm that is held in flexion. Elbow dislocations require a significant amount of force. Up to 20% of elbow dislocations are associated with fractures.2 Simple elbow dislocations have a better prognosis and are less likely to require surgical intervention than complex ones (fracture-dislocations). This chapter deals with the closed reduction of simple elbow dislocations.

One particular type of dislocation pertains primarily to the pediatric population. Subluxation of the radial head, often referred to as a “nursemaid's elbow,” occurs commonly in preschool children. It is rarely seen after age 7 and represents 20% of upper extremity injuries in children.5 It occurs after sudden traction on the radius with an extended elbow, as when an adult pulls a child up into a standing position by one arm. The annular ligament slips between the capitellum and the head of the radius, impeding supination of the arm. The patient will present with the arm held in slight flexion and pronation, usually in not much distress, and not using the affected arm. The simple reduction of this dislocation is also addressed.

The elbow is a hinge joint comprising articulations between the humerus, the ulna, and the radius (Figure 82-1). The distal humerus consists of the extraarticular medial and lateral epicondyles, which are diverging columns separated by the intraarticular trochlea and capitellum. The trochlea articulates with the proximal ulna. The articular surfaces of the trochlea extend from the coronoid fossa anteriorly to the olecranon fossa posteriorly. The anterior and posterior fossae provide space for the coronoid and olecranon, respectively, at the extremes of motion. The capitellum is a spherical structure that articulates with the concave radial head.

Numerous neurovascular structures cross the elbow (Figure 82-2). The prominent medial epicondyle protects the ulnar nerve, which travels in its posterior sulcus. The radial nerve travels just anterior to the lateral epicondyle. The median nerve travels with the brachial artery through the antecubital fossa.

There are four ligamentous structures of importance in considering injuries to the elbow: the radial collateral ligament, the ulnar collateral ligament, the annular ligament, and the anterior capsule (Figure 82-3). The annular ligament and radial collateral ligament hold the radial head in position. The annular ligament allows the radial head to rotate under it during pronation and supination.

The relationship of the radius and ulna to the humerus is used to classify elbow dislocations into posterior, anterior, medial, lateral, and divergent (Figure 82-4). The majority of elbow dislocations are posterior in direction.6 The other types of elbow dislocations are uncommon.6 The radius and ulna are held tightly together by the annular ligament and the interosseous membrane (Figure 82-3). Posterior elbow dislocations result in the radius and ulna projecting posterior to the humerus (Figures 82-4A & 82-5). The radius and ulna may be slightly lateral or medial in posterior elbow dislocations in addition to being posteriorly displaced. This does not affect the management or prognosis. The presence of a fracture of the radial head or coronoid process may frequently render any attempt at reduction unstable and will usually require an open reduction.7 Anterior elbow dislocations occur from traction of the forearm with the elbow extended or a blow to the posterior aspect of the flexed elbow. Anterior elbow dislocations result in the radius and ulna projecting anterior to the humerus (Figure 82-4B). Medial (Figure 82-4C) and lateral (Figure 82-4D) dislocations are rare injuries with poorer prognoses. Divergent dislocations (Figure 82-4E) are rare injuries that are distinct from the other types of elbow dislocations because there is dissociation of the radius and ulna. The annular ligament and interosseous membrane must be torn for a divergent dislocation to occur.

The patient usually presents with pain and swelling of the elbow. All elbow dislocations are characterized by loss of the normal relationship of the humeral epicondyles to the tip of the olecranon. The bony landmarks may be identified if the patient is seen immediately after the injury. However, the swelling and hemarthrosis that develop over time make it difficult to palpate these landmarks. Posterior dislocations are further apparent by a shortening of the forearm and the elbow being fixed in flexion.

All elbow dislocations require reduction. Early reduction of a dislocation, by open or closed means, is of paramount importance if good functional results are to be obtained. Closed reduction is unlikely to be successful if attempted later than 14 days after the injury.4 The more promptly the reduction is attempted, the more likely it is to be successful.

The vascular status of the extremity also dictates the need for emergent relocation. Emergent and immediate relocation is necessary when there is neurologic or vascular compromise of the distal extremity. Relocation can await titration of sedation and analgesia when the extremity is neurovascularly intact.

There are no absolute contraindications to the closed reduction of an elbow dislocation. A relative contraindication to the procedure is when there is uncertainty, before radiographic evaluation, if the injury is a dislocation or a fracture. Closed reduction is not indicated if there is an interposed osteochondral fragment preventing concentric reduction or when there is a concomitant displaced fracture of the radial head or neck. Elbows that have been dislocated for a prolonged period of time may have closed reduction attempted but will most likely require an open procedure.

• Towel or sheet to aid in applying traction
• Splinting materials
• Weight (sandbag, bucket with water, or any other weight)
• Procedural sedation supplies (see Chapter 129)

Explain the risks, benefits, and potential complications to the patient and/or their representative. The postprocedural care should also be discussed. Obtain an informed consent for the reduction procedure.

Carefully assess and document the preprocedural neurologic (median, radial, and ulnar nerves) and vascular (brachial, radial, and ulnar arteries) status of the extremity. Splint and/or sling the affected extremity until radiographs are obtained and a closed reduction can be performed. Obtain anteroposterior and lateral radiographs to confirm the diagnosis of an elbow dislocation. Oblique views may be helpful to further define the relationship between the distal humerus, radius, and ulna. The only case for which a preprocedure radiograph is not indicated is when neurologic or vascular compromise exists in the distal extremity and an expeditious reduction is required.

Closed reduction of elbow dislocations requires adequate analgesia and muscle relaxation. In most cases, procedural sedation is useful. Regional anesthesia (axillary nerve or Bier blocks) is useful if procedural sedation is contraindicated. Refer to Chapters 126 and 127 for details regarding regional anesthesia of the upper extremity. General anesthesia with fluoroscopy is rarely necessary unless the dislocation is associated with an undisplaced fracture of the radial head or neck.

Posterior Elbow Dislocation Reduction Techniques

The goal of closed reduction is to distract the radius and ulna, allowing them to relocate. The preferred technique that provides the least complications is a modification of the Stimson technique used for shoulder dislocations.8 Place the patient prone with the affected arm hanging off the gurney (Figure 82-6). Place padding anteriorly in front of the arm and shoulder so that the arm does not drag along the side of the gurney. Care must be taken that the patient does not fall from the gurney. Tie a sheet circumferentially around the patient's hips and the gurney. Ensure that the patient does not have any respiratory difficulty while in the prone position. Suspend a weight from the patient's wrist to apply traction to the arm (Figure 82-6). The weight should be approximately 5 pounds and may go up to 15 pounds, depending on the patient's musculature and weight. Allow the arm to dangle over the edge of the gurney for 10 minutes. If the elbow dislocation will not reduce, attempt the traction-countertraction technique.

The traction-countertraction technique can be performed but is not the optimal approach. Place the patient's arm in slight flexion. Grasp the patient's midhumerus with the nondominant hand and the patient's wrist with the dominant hand (Figure 82-7A). Alternatively, an assistant can grasp the humerus while the physician uses both hands to grasp the patient's wrist (Figure 82-7B). Stabilize the patient's humerus. Apply steady and constant traction to the patient's wrist to distract the coronoid process and allow it to slip past the humerus and back into anatomic position. The application of downward pressure on the proximal forearm can help to disengage the coronoid process from the olecranon fossa and ease the reduction.

Medial and Lateral Elbow Dislocation Reduction Technique

Medial and lateral dislocations of the elbow are extraordinarily uncommon. They are usually associated with a posterior elbow dislocation. These dislocations can be reduced in a similar manner using the traction-countertraction technique for that of the posterior elbow dislocation. For lateral dislocations, apply traction to the patients wrist with one hand while using your other hand to guide the proximal ulna downward, then medially, and finally backward. For medial dislocations, apply traction to the patients wrist with one hand while using your other hand to guide the proximal ulna downward, then laterally.

Emergency Physicians should not reduce a medial or lateral elbow dislocation. They are uncommon, may be associated with neurovascular complications, have severe ligamentous tears, and should be reduced by an Orthopedic Surgeon. The only exception to this is if there is neurologic and/or vascular compromise of the distal extremity and no Orthopedic Surgeon is immediately available.

Anterior Elbow Dislocation Reduction Technique

Anterior elbow dislocations are uncommon. They are often associated with intimal injuries to the brachial artery, from being stretched during the injury.

Anterior elbow dislocations should be reduced by an Orthopedic Surgeon for the same reasons as a medial or lateral elbow dislocation. The only exception to this is if there is neurologic and/or vascular compromise of the distal extremity and no Orthopedic Surgeon is immediately available.

Divergent Elbow Dislocation Reduction Technique

Fortunately, divergent dislocations are exceedingly rare. They are commonly associated with severe articular damage, interosseous ligamentous tears, neurologic injuries, and vascular injuries. The reduction technique is complex; the elbow is reduced as a two-part dislocation and often requires surgical fixation to be stabilized. Simple traction can be applied to relieve stress on the neurovascular structures but will not reduce the dislocation due to the instability of the joint.

Divergent elbow dislocations should be reduced by an Orthopedic Surgeon in the Operating Room. The only exception to this is if there is neurologic and/or vascular compromise of the distal extremity and no Orthopedic Surgeon is immediately available.

Radial Head Subluxation Reduction

This condition is also referred to as a “nursemaid's elbow.” Reduction of a radial head subluxation is a maneuver involving supination and flexion of the affected forearm. The forearm is quickly supinated and the elbow flexed completely in one smooth motion. A pop or click is sometimes heard or felt by the Emergency Physician as the subluxation is reduced. Most patients are asymptomatic within 5 to 10 minutes and 90% within 30 minutes.9 The Emergency Physician should leave the room for 5 to 10 minutes after the procedure. Ask the parents to distract the child to see if they begins to move the arm. A fearful child will often not use a successfully reduced arm in fear of pain. Place an object (e.g., car keys, popsicle, toy, or other object the child may want) within grasp of the reduced extremity to encourage the child to use the extremity. Refer to Chapter 83 for the complete details regarding the reduction of a radial head subluxation.

After a reduction, gently move the joint through the entire range of motion to ensure smooth movement and proper joint reduction. This also tests for joint stability and whether or not the joint will easily re-dislocate. The joint may need to be repaired operatively if it dislocates during this examination. The neurovascular status of the extremity must again be evaluated and documented. The integrity of the median, ulnar, and radial nerves as well as the brachial artery and its distal branches must be evaluated and documented. All reductions except radial head subluxations should have postprocedural radiographs to ensure proper bony alignment and the lack of a fracture. If full and smooth passive range of motion is not possible, which is especially common in children, postreduction radiographs should be examined for entrapment of the medial epicondyle.

Place the reduced extremity in a posterior long arm splint, from the midhumerus to the base of the fingers, with the elbow in 90° of flexion. Do not apply a circumferential cast due to the subsequent swelling and edema. Suspend the arm with a sling to aid in elevating the extremity. The patient should be carefully observed for 12 to 36 hours for vascular impairment. Instruct the patient to return to the Emergency Department if they develop weakness, numbness, paresthesias, cold fingers, or cyanotic fingers. The patient should be admitted for observation if there is any question of neurovascular compromise. Gentle range-of-motion exercises can be started as early as 3 to 5 days postreduction if the elbow is stable.10 Schedule follow-up with an Orthopedic Surgeon 3 to 4 days postreduction to test for joint stability. Prescribe nonsteroidal anti-inflammatory drugs supplemented with narcotic analgesics to control pain.

No immobilization is necessary for a radial head subluxation that is reduced. Immobilization in a sling with follow-up by an Orthopedic Surgeon is recommended only for recurrent radial head subluxations.

Several serious complications exist with elbow dislocations. The most serious and first to happen are ischemic complications. Damage to and obstruction of the brachial artery can occur with any of the elbow dislocations. Brachial artery injury occurs in 5% to 13% of patients with an elbow dislocation.11 It is a serious complication that can occur even without an associated fracture.11 The presence of a distal pulse is not proof that there is no vascular injury. Collateral circulation around the elbow can result in a distal pulse despite a complete brachial artery laceration or occlusion.12 Signs of an arterial injury include: cyanosis, an expanding hematoma, pallor, pulselessness, and severe pain. Any suspicion of a brachial artery injury necessitates prompt angiography.12,13

The second serious complication resulting from an elbow dislocation is nerve injury from traction or entrapment. Loss of median nerve function postreduction should prompt an immediate consultation with an Orthopedic Surgeon. The ulnar nerve is most commonly injured.14 It is seen in 8% to 20% of patients with posterior elbow dislocations.14

Fractures commonly occur with elbow dislocations. Radiographs should always be obtained before and after any attempt at reduction. The only exception to obtaining prereduction radiographs is if the extremity has signs of distal neurovascular compromise and obtaining radiographs will delay the reduction. A fractured coronoid process can sometimes become entrapped in the joint, requiring an open reduction. Fractures of the coronoid process are commonly associated injuries and will usually come into near-normal opposition once reduction occurs (Figure 82-8). Large fragments that are displaced may require operative fixation.

Late complications of elbow dislocations include posttraumatic stiffness, posterolateral joint instability, ectopic ossification, and occult distal radioulnar joint disruption.15

Elbow dislocations are the second most common large joint dislocations that occur in adults. The majority of dislocations are posterior elbow dislocations, although the radius and ulna can dislocate into just about any other position. Relocation involves distracting the forearm while stabilizing the humerus and putting pressure counter to the direction of the dislocation. It is not uncommon to have associated fractures, so radiographic studies are imperative. The neurovascular status of the extremity must be carefully monitored and documented both before and after any attempts at reduction. Splint the elbow in flexion postreduction. Follow-up with an Orthopedic Surgeon and early range-of-motion exercises are recommended to ensure proper joint function.