Elbow Dislocation 

Updated: Sep 26, 2017
Author: Mark E Halstead, MD; Chief Editor: Craig C Young, MD 

Overview

Background

Elbow dislocation is the most common dislocation in children; in adults, it is the second most common dislocation after that of the shoulder.[1, 2, 3, 4, 5] The elbow is amazingly stable, relying more on bony anatomy configuration for stability rather than ligaments. Considerable force is necessary to dislocate the elbow; sports activities account for up to 50% of elbow dislocations, and this type of injury is more commonly seen in adolescent and young adult populations (see the image below).

Posterior and lateral dislocation of the left elbo Posterior and lateral dislocation of the left elbow in a soccer goalie. A small avulsion fracture of the olecranon is present.

Posterior elbow dislocations comprise over 90% of elbow injuries. Early recognition of this injury is required due to the need for early reduction, given a higher likelihood for poor function and possible neurovascular compromise with delays in reduction.[1, 2, 3, 4, 6, 7] Associated fractures are not infrequent with elbow dislocations, given the force that is required to dislocate the elbow.

Anterior dislocations are seen much less commonly than posterior dislocations. Divergent dislocations, which result in the ulna and radius dislocating in opposite directions, are even more rare. In the pediatric population, radial head subluxation is the main cause of elbow dislocations.

For excellent patient education resources, visit eMedicineHealth's First Aid and Injuries Center. Also, see eMedicineHealth's patient education articles Elbow Dislocation and Broken Elbow.

Epidemiology

Frequency

United States

The rate of elbow dislocation is 6-13 cases per 100,000 people, and this injury occurs more frequently in males than in females. Of all elbow dislocations, 10-50% are sports related. More than 90% of elbow dislocations are posterior dislocations.

Dizdarevic et al reported 9.2% of all elbow injuries in high school athletics are elbow dislocations with a dislocation rate of 0.38 per 100,000 athletic exposures. Boys wrestling (46%) and boys football (37%) were the sports most frequently associated with dislocations. Boys sports accounted for 91.3% of all dislocations and occurred more frequently in competition than in practice.[8]

Functional Anatomy

The elbow is primarily a flexion-extension hinge joint, which also allows for pronation and supination. Normal range of motion (ROM) at the elbow should be extension to 0° and flexion to 150°.[1, 2]

The humerus and ulna form a very stable unit, which is generally resistant to disruption unless considerable force is applied. This inherent stability also reduces the likelihood of redislocation. The primary bony stabilizers are the coronoid and radial head.

The medial collateral ligament (MCL) and lateral collateral ligament (LCL) comprise the ligamentous stability of the elbow and act as a back-up system to the elbow's natural bony stability. The MCL consists of 3 bands, the anterior oblique, posterior oblique, and the transverse. The anterior band provides most of the resistance to valgus stress. The LCL has 2 bands, the ulnar collateral and radial collateral.

The 2 main compartments of the elbow are the anterior and posterior compartments. The anterior compartment contains the brachial artery and the ulnar and median nerves. This compartment is more commonly affected by dislocations and is the reason for clinical concern regarding brachial artery disruption and median or ulnar nerve entrapment.[1, 2, 4, 9]

The ulnar nerve passes posteriorly to the medial epicondyle of the humerus, and then it travels deep in the forearm before becoming more superficial again at the wrist. The close proximity of the ulnar nerve to the medial epicondyle allows for the increased likelihood of entrapment when a dislocation occurs. The median nerve is also frequently affected and travels intimately with the brachial artery, which predisposes to simultaneous injury for both the artery and nerve. The posterior compartment contains the radial nerve and triceps brachii muscle.

Anatomically, the mechanism for elbow dislocations is believed to occur as a continuum of damaged/torn structures, beginning laterally with the ulnar portion of the LCL, followed by complete LCL disruption, then damage to the anterior and posterior compartments. The posterior MCL can then become damaged, leaving the anterior portion intact. Further force can allow the elbow to pivot about the anterior bundle of the MCL, potentially damaging it. The LCL, therefore, is considered to be the initial weak link in elbow dislocations.

In the pediatric population, the clinician should be aware of the 6 ossification centers of the elbow joint as well as the annular ligament. The capitellum, radial head, internal (medial) epicondyle, trochlea, olecranon, and external (lateral) epicondyle (CRITOE) is the order in which the ossification centers appear. These centers may often be mistaken for fractures on x-rays. NOTE: A general rule of thumb for the time of appearance of the ossification centers is "1-3-5-7-9-11," which are the ages in years, corresponding to the CRITOE mnemonic.

In cases in which there is radial head subluxation, the radial head slips under the annular ligament and becomes trapped.

Sport-Specific Biomechanics

Biomechanically, no single sport definitively increases the risk of elbow dislocations; however, sports that increase the likelihood of a person falling onto an outstretched hand (ie, FOOSH injury) (eg, gymnastics, rollerblading, cycling) may theoretically increase the risk of elbow dislocation.

 

Presentation

History

In posterior elbow dislocations, the patient often describes falling on an outstretched hand (ie, the FOOSH injury) as the mechanism of injury. Some clinicians speculate that the elbow is more likely to dislocate when it is slightly abducted and flexed. When compressive forces are directed on to the outstretched hand, the radius and ulna, along with the valgus force at the elbow, suffer the common posterolateral dislocation. These forces also contribute to associated fractures. In addition, hyperextension at the elbow has been seen with elbow dislocations.

Anterior dislocations are usually the result of a direct posterior blow to a flexed elbow. Associated fractures of the olecranon are commonly seen.

Divergent dislocations are very rare injury and are associated with significant high-energy trauma to the elbow.

In children, radial head subluxations often occur when the arm is pulled. The child commonly holds the arm pronated, mildly flexed, and abducted against the body and refuses or fights any manipulation of the affected arm.

Essential elements of the dislocation history include the mechanism of the injury, the time between the injury and presentation, functioning, previous attempts at reduction/manipulation, swelling, location, and the type of pain.

Physical

Neurovascular assessment and documentation of the clinical evaluation are essential in any elbow dislocation because associated brachial artery and ulnar nerve injuries are frequent. Median nerve injuries are also common.

Evaluate the injury for swelling.

Note any deformities that are present.

Posterior elbow dislocations often have a very prominent olecranon and a forearm that appears foreshortened.

Anterior elbow dislocations have the appearance of an elongated forearm, and the arm is held in extension.

Touch sensation of the median and ulnar nerves can be quickly assessed by testing the distal palmar aspect of the first through fifth digits. (The ulnar nerve innervates the medial one half of the fourth digit and the fifth digit, as well as the dorsal side of the same digits.)

Motor function of the median and ulnar nerve can be quickly assessed by evaluating the abduction and adduction strength of the digits (ulnar nerve) and the opposability of the thumb (median nerve).

Causes

Unlike the shoulder, a previous elbow dislocation does not predispose a patient to future dislocations. Elbow dislocations are commonly caused by a fall on an outstretched hand or by a traumatic event. Radial head subluxations in children are usually caused by pulling or yanking on the child's arm when the child's elbow is extended.

 

DDx

 

Workup

Imaging Studies

Before reduction of the injury, obtain anteroposterior and lateral radiographs of the elbow (see the image below). If clinicians feel comfortable trying a reduction in the field, they may do so before obtaining radiographs; however, postreduction films should be obtained and the affected limb's neurovascular status should be documented pre- and postreduction.

Posterior and lateral dislocation of the left elbo Posterior and lateral dislocation of the left elbow in a soccer goalie. A small avulsion fracture of the olecranon is present.

Postreduction films are also necessary to ensure adequate reduction and to evaluate for fractures. The recreation of a normal radiocapitellar line (the line drawn through the shaft of the radius through the center of the capitellum) should be evident on all radiographic views.

Ultrasound is also used to diagnose elbow pathology by presenting real-time, high-resolution imaging of tendons, ligaments, and nerves.[10]

CT scanning may be useful in the evaluation for the full extent and location of fractures that may occur with a complex elbow dislocation.

MRI has little use in an acute elbow dislocation.

Other Tests

A role may exist for angiography in the evaluation of a suspected associated arterial injury; however, if angiography would significantly delay vascular repair, the operating room may be a more appropriate setting for its use.

Procedures

Several methods for reducing a posterior elbow dislocation have been suggested.[1, 2, 3, 4, 11, 12, 13, 14, 15] Before reduction, adequate patient analgesia and sedation are necessary not only for patient comfort but also for the reduction. Radial head subluxations in children (ie, nursemaid's elbow) can generally be reduced without the need for sedation or analgesia. The 2 most commonly used techniques for the posterior dislocation are as follows:

  • The author's preferred method is to place the patient in a prone position with the affected elbow flexed at 90° and the humerus supported by the table (see the image below). The hand of the affected arm should be pointing toward the ground. Apply downward traction to the forearm, which is held in slight pronation, while using the other hand to grasp the humerus, and apply pressure to the olecranon in a downward motion to facilitate reduction.

    The preferred method for posterior elbow dislocati The preferred method for posterior elbow dislocation reduction is to lay the patient prone with the humerus supported by the exam table. Place one hand around the wrist of the affected arm and apply downward traction, while the other hand stabilizes the humerus and the thumb is placed over the olecranon, with gentle pressure applied to facilitate reduction.
  • A second method involves the patient lying supine with the affected arm extended to the side in slight flexion. An assistant applies traction to the humerus toward the patient's body, while a second individual applies in-line traction to the forearm, the latter of which is held slightly flexed and supinated to facilitate reduction.

Perform anterior elbow dislocation reductions by grasping the humerus with 2 hands to apply countertraction, while an assistant provides in-line traction to the forearm. Orthopedic assistance may be beneficial given the infrequency of anterior dislocations.

Treat radial head subluxations in children by supporting the child's affected arm with your nondominant hand, with moderate pressure placed on the radial head. With your dominant hand on the child's wrist, apply gentle traction to the arm, and in 1 motion, supinate and fully flex the affected elbow. You can palpate for a click over the radial head with your nondominant hand.

Some studies have suggested that hyperpronation may be a more effective way to reduce the subluxation.[16] The hyperpronation method also may be attempted if a subluxation cannot be reduced by the more commonly used supination and flexion method.

Postreduction

Place the elbow through gentle ROM testing. ( NOTE: Extending the elbow beyond 20° from full extension may cause the elbow to redislocate and is not recommended.) Inability to move the elbow smoothly through ROM following reduction should raise the suspicion of a trapped medial epicondyle fracture. Reexamination for neurovascular integrity should take place postreduction, followed by follow-up elbow radiographs. The elbow joint is expected to be unstable following a dislocation. ( NOTE: Assessment for stability following reduction is likely to be painful for the patient and does not provide further information for the management of this condition.)

If near-full ROM is present in the affected elbow without associated fractures, the elbow may be splinted using a posterior splint, with the forearm in slight pronation and the elbow flexed at 90°.

If there are any concerns regarding potential neurovascular compromise or excessive swelling, or the risk of compartment syndrome exists, it would be beneficial to admit the patient to a hospital for a 24-hour period of observation following the injury.

For on-site reductions, such as at a game or in a training room where radiographs may not be readily available, a physician who feels comfortable reducing an elbow may do so, provided the physician performs and documents a complete neurovascular examination before and after the reduction.[4] Because of the high association of fractures with elbow dislocations, the patient should be advised to obtain radiographs of the elbow soon after the reduction.

 

Treatment

Acute Phase

Rehabilitation Program

Physical Therapy

Early ROM exercises in stable, reduced elbow dislocations has been shown to be associated with an improved outcome. However, immobilization of the affected elbow for longer than 3 weeks in patients following an elbow dislocation has been associated with loss of ROM compared with patients who start early ROM exercises.[14, 17]

A study by Iordens et al compared outcomes of early mobilization and plaster immobilization in patients with a simple elbow dislocation. The study found that patients in the early mobilization group recovered faster and returned to work earlier without increasing the complication rate.[18]

Medical Issues/Complications

Brachial artery disruption may be seen in any elbow dislocation and special attention should be made in open dislocations.

Ulnar nerve injury may occur in up to 15% of elbow dislocations. Perform an initial neurovascular assessment and frequent reassessments.

Median nerve injury is frequently seen in conjunction with brachial artery injuries because both of these structures are in close anatomic proximity. The median nerve function should always be assessed with a higher suspicion of injury if a brachial artery injury is known to exist. The median nerve may also be injured or entrapped during a reduction.

Associated fractures for elbow dislocation include those of the radial head or neck (5-10%), medial/lateral epicondyle avulsions (10%), those of the coronoid process (10%), and fractures of the distal radius, ulna, and proximal humerus (10%).

Compartment syndrome may develop in the forearm fascia or biceps tendon due to massive swelling, which may occur in an acute elbow dislocation. Compartment syndrome must be considered in the differential diagnosis in the presence of persistent patient pain, particularly when exacerbations of pain occur with passive finger and wrist extension of the dislocated arm.

Ectopic calcification, primarily around the collateral ligaments, is common after an elbow dislocation, provides no limitations and requires no intervention.

Myositis ossificans may also be seen if significant hemarthrosis developed with the elbow dislocation.

Surgical Intervention

Seek surgical intervention by an orthopedist if any signs of neurovascular compromise, associated fractures, or nonreducible dislocations are present.

Consultations

Obtain orthopedic consultation if any signs of neurovascular compromise, associated fractures, or nonreducible dislocations are present.

Recovery Phase

Rehabilitation Program

Physical Therapy

Patients with limitations in ROM on follow-up evaluation may benefit from more aggressive physical therapy to regain loss of mobility.

Maintenance Phase

Rehabilitation Program

Physical Therapy

Depending on the severity of the elbow dislocation, it may take several months for the elbow to fully heal. Muscle-strengthening activities, in addition to the ROM program, are important to improve endurance of the elbow. Incorporate sport-specific training as the athlete progresses through rehabilitation to ensure a safe return to his/her sport.[19]

Surgical Intervention

Surgical intervention may be needed for a functional flexion contracture or for chronic residual instability.[20, 21, 22]

 

Medication

Medication Summary

Use of medication for elbow dislocations is beneficial in the acute setting when reduction of the dislocation is to take place. Choosing both an anxiolytic and a pain medication is ideal for a conscious sedation to facilitate reduction. Once reduction has occurred, pain may still be an issue, and it would be reasonable to provide the patient with oral pain medication to use in the outpatient setting.

Anxiolytics

Class Summary

Anxiolytics allow for relaxation and mild sedation when reduction of a dislocated elbow is attempted. These agents also allow for a lower dose of analgesics to be used.

Midazolam (Versed)

DOC for anxiolytics. Shorter-acting benzodiazepine sedative-hypnotic that is useful in patients requiring acute and/or short-term sedation. Midazolam is also useful for its amnestic effects.

Lorazepam (Ativan)

Sedative hypnotic with short onset of effects and a relatively long half-life. By increasing the action of gamma-aminobutyric acid (GABA), which is a major inhibitory neurotransmitter in the brain, this agent may depress all levels of CNS, including the limbic and reticular formation. When the patient needs to be sedated for longer than a 24-hour period, this medication is excellent.

Diazepam (Valium)

Depresses all levels of the CNS (eg, limbic and reticular formation), possibly by increasing the activity of GABA. Individualize the dosage and increase cautiously to avoid adverse effects.

Analgesics

Class Summary

Pain control is essential to quality patient care. Analgesics ensure patient comfort, promote pulmonary toilet, and have sedating properties, which are beneficial for patients who have sustained trauma or who have sustained injuries.

Morphine (Duramorph, Astramorph, MS Contin)

Indicated for moderate to severe acute and chronic pain.

Fentanyl (Duragesic, Sublimaze)

Potent narcotic analgesic with a much shorter half-life than morphine sulfate. DOC for conscious sedation analgesia. Ideal for analgesic action of short duration during anesthesia and immediate postoperative period.

Excellent choice for pain management and sedation with short duration (30-60 min) and easy to titrate. Easily and quickly reversed by naloxone. After initial dose, the subsequent doses should not be titrated more frequently than q3h or q6h thereafter.

When using the transdermal dosage form, most patients are controlled with 72 h dosing intervals. However, some patients require dosing intervals of 48 h.

Oxycodone and acetaminophen (Percocet, Roxicet)

Drug combination indicated for the relief of moderate to severe pain.

Acetaminophen and codeine (Tylenol with codeine, Tylenol #3)

Indicated for the treatment of mild to moderate pain.

Acetaminophen and hydrocodone (Vicodin, Hydrocet, Lorcet)

Drug combination indicated for moderate to severe pain.

 

Follow-up

Return to Play

A follow-up examination before the patient's return to play is necessary to reassess motion of the formerly dislocated elbow following the immobilization and early ROM period. Most individuals can return to play 3-6 weeks following an elbow dislocation.

In sports in which an elbow dislocation occurs in a player's nondominant arm, return to play may occur at the earlier end of the rehabilitation spectrum — as long as motion is back to a level that is suitable to the physician and athlete. For elbow dislocations that occur in a player's dominant arm, return to play may take a longer time period. Throwing sports, such as baseball, may require the patient to undergo periods of rest up to 3 months following a dislocation, followed by a strengthening rehabilitative program once full motion is achieved.

Complications

Complications of elbow dislocation primarily include neurovascular compromise, compartment syndrome, and loss of ROM. Chronic regional pain syndrome may occur. Close attention to the neurologic examination pre- and postreduction as well as at the follow-up visit may alert the physician to potential neurologic problems.

Prevention

Elbow dislocations in children due to radial head subluxation (nursemaid's elbow) are often preventable. A child should not be forcibly pulled, lifted, or swung in the air by the hand or wrist. Always lift a small child from under the arms, rather than by the hand or wrist. Athletes who participate in high-risk sports, where falling on an outstretched arm is common, may be advised to wear protective gear to prevent elbow injuries.

Prognosis

Approximately 50% of patients with dislocated elbows achieve a full recovery, including full ROM. One third of patients experience some limitation of motion at the elbow, usually less than 10° of compromised motion. The remaining 10-15% of patients have more significant losses in function, primarily related to limited ROM. Some correlation exists between the severity of the initial injury and the likelihood of having significant motion limitations further in time from the injury occurrence.[23, 24]