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What is Posterior Elbow Dislocation?

Posterior elbow dislocation is the most common type of joint dislocation in children that are less than 10 years old. In adults, it is the second most commonly dislocated joint – preceded only by shoulder dislocations. 

Approximately 90% of all elbow dislocations are commonly seen in the non-dominant upper extremity.

Posterior elbow dislocation is a traumatic injury of the elbow, occurring when the radius and ulna are vigorously driven posterior to the humerus. Specifically, the olecranon process of the ulna (the tip of your elbow) moves into the olecranon fossa of the humerus and the trochlea of the humerus is displaced over the coronoid process of the ulna.

Characteristics and Clinical Presentation of Posterior Elbow Dislocation

A posterior elbow dislocation can be classified as simple or complex. A simple dislocation is absent of fractures while a complex dislocation has related fractures.

Fractures may exist on the radial head, coronoid process, olecranon, humeral condyles, or capitellum. These fractures lead to disruption of the medial collateral ligament, lateral collateral ligament, or the interosseous membrane.

The ‘terrible triad’ is a term used to describe a complex dislocation with intra-articular fractures of the radial head and coronoid process. Elbow dislocations are staged depending on the disruption of different stabilizers, such as the ulnohumeral articulation, medial collateral ligament, and lateral collateral ligament.

Signs and Symptoms of Posterior Elbow Dislocation

A complete elbow dislocation is extremely painful. The arm will be deformed and may have an obvious twist at the elbow. A partial elbow dislocation or subluxation is difficult to identify without a professional examination.

Neurovascular injury is uncommon from posterior elbow dislocations. Clinical evaluation should include the median and ulnar nerve function. Damage to the brachial artery can be assessed by palpating for a radial pulse.

Causes of Posterior Elbow Dislocation

An elbow can be dislocated by landing on it with an outstretched hand. Dislocations occur when the radius and the ulna fall out of place with the humerus. Elbow fractures may be classified as being simple or complex.

A simple elbow dislocation means there is no fracture within the injury, but a complex elbow dislocation may mean that there is a fracture somewhere where the radius, ulna, and humerus all meet.

Injuries Associated with Posterior Elbow Dislocation

The elbow is stable because of the combined stabilizing effects of bone surfaces, ligaments, and muscles. When an elbow dislocates, any or all of these structures can be injured to different degrees.

In the most severe dislocations, the blood vessels and nerves that travel across the elbow may be injured. If this happens, there is a risk of losing the arm.

During the physical examination, Drs. Jason or Mark Pruzansky will examine the arm, checking for tenderness, swelling, and deformity. Injuries with damaged blood vessel associated with the dislocation may mean the hand will be cold to the touch and may take on a bluish appearance.

It is also important to check the nerve supply to the hand. If nerves have been injured during the dislocation, some or all of the hand may be numb and not able to move.

Complex elbow dislocation consists of both ligamentous and bony injuries. The radial head and coronoid process are the most commonly fractured structures.

Other structures that can be damaged include medial and lateral collateral ligaments; medial and lateral condyles/epicondyles; transolecranon fractures; and posterior Monteggia fractures.

X-rays are needed to confirm that the elbow is dislocated. If bone detail is difficult to identify on an x-ray, a computed tomography (CT) scan may be done.

If it is important to evaluate the ligaments, a magnetic resonance image (MRI) can be helpful, however, it is rarely required.

Treatment Options for Posterior Elbow Dislocations

An elbow dislocation is a serious injury. The goal of immediate treatment is to return the elbow to its normal alignment and minimize discomfort and damage. The long-term goal is to restore function to the arm.

Nonsurgical Treatments for Posterior Elbow Dislocation

The normal alignment of the elbow can usually be restored in the emergency department. It requires adequate muscular relaxation and appropriate analgesia.

Reduction may be achieved by the correction of the medial or lateral displacement followed by strong traction on the forearm in the line of the limb.

Traction should be maintained with the arm in moderate flexion, using counter-traction with the fingers. Palpation should ensure the equilateral triangle formed by the olecranon and epicondyles is present.

Simple elbow dislocations are treated by keeping immobilizing the arm in a sling or a splint for 1-3 weeks. Physical therapy is recommended immediately after the immobilization period ends to reduce the possibility of reducing the arm’s range of motion due to inactivity. Drs. Pruzansky take special care to ensure that all patients leave with adequate instructions for rehabilitation.

In severe cases, some people may never be able to fully open (extend) the arm, but the elbow can work very well even without the full range of motion. Once the elbow’s range of motion improves, Drs. Pruzansky may recommend a strengthening program.

Surgical Treatment Options for Posterior Elbow Dislocation

In events involving complex elbow dislocations, patients may require surgery to restore proper alignment. Surgery may also involve ligamentous repair. Because a complex elbow dislocation is difficult to realign, the elbow must be protected with an external hinge following surgery.

This device is designed to protect the elbow from improper dislocation. If the injury has associated blood vessel or nerve injuries, patients may require additional surgery.

If You Believe You Have Posterior Elbow Dislocation, Contact HandSport Surgery Institute

Please contact us as soon as possible to schedule an appointment with our talented team. People experiencing posterior elbow dislocation should be evaluated to try and prevent further injury and mobility issues.

If you have been injured, it’s important to be evaluated by a highly skilled professional. Call Drs. Mark and Jason Pruzansky at 212-249-8700 to schedule an appointment, obtain an accurate diagnosis, and start to restore comfort to your elbow.

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