Anterior Elbow Dislocations – Causes, Symptoms, Treatment

The elbow is one of the most common large joints to dislocate and is the most common large joint dislocated in children.[rx] However, anterior elbow dislocations are a rare injury in both adults and children. On a basic level, the elbow is comprised of the articulation between the distal humerus with the proximal radius and ulna. Elbow dislocations are described by the direction of the proximal ulna relative to the humerus. Therefore, an anterior dislocation is described as a proximal ulna being forced anterior to the distal humerus with or without the proximal radius. The mechanism is usually falling on a flexed elbow with anterior force on the proximal ulna.[rx]

Causes of Anterior Elbow Dislocations

Falling onto an outstretched arm with an anterior force on the proximal ulna leads to an anterior elbow dislocation.

This injury and its complications are best understood after reviewing pertinent anatomy. The elbow is a joint made up of the articulation between three bony structures, the humerus, ulna, and radius. The distal humerus is the most proximal aspect of the elbow. The distal humerus flares out medially and laterally making the medial and lateral epicondyles. The trochlea and capitellum make up the distal joint surface of the humerus, articulating with the greater sigmoid notch of the proximal ulna and the radial head respectively.[rx]

The olecranon is the posterior portion of the proximal ulna and forms the posterosuperior part of the greater sigmoid notch.[rx] The coronoid process of the proximal ulna forms the anterior portion of the notch and is where the brachialis and anterior medial collateral ligament attach. Laterally, the proximal ulna has the lesser sigmoid notch also called the radial notch where the proximal radius articulates.

The soft tissue surrounding the elbow joint contributes to the stability of this three-part joint. The annular ligament is a ligament that surrounds the radial head and is an insertion site of the joint capsule. The joint capsule also inserts onto the anterior aspect of the coronoid. Posteriorly, the joint capsule attaches to the olecranon. The capsule contributes to the varus-valgus stability of the elbow when in extension.[rx] Varus-valgus stability of the elbow is also reinforced by the medial and lateral collateral ligaments.

The medial ulnar collateral ligament contributes to the valgus stability of the elbow and consists of the anterior, posterior, and transverse bands. The medial collateral ligament originates from the medial epicondyle and inserts at the base of the coronoid.[rx]

The lateral collateral ligament contributes to the varus stability of the elbow and also consists of three components: the lateral ulnar collateral ligament, the annular ligament, and the radial collateral ligament.[rx] The lateral ulnar collateral ligament inserts on the lateral epicondyle and the supinator crest on the proximal ulna, giving the elbow posterolateral stability. The annular ligament wraps around the radial head and attaches to the radial notch on the ulna, stabilizing the radioulnar joint. The radial collateral ligament also stabilizes the radial head by attaching to the lateral epicondyle and the annular ligament.

There are multiple neurovascular structures that cross the elbow joint that are at risk for injury during an elbow dislocation. The brachial artery crosses the elbow joint anteriorly before branching into the radial and ulnar artery distally in the forearm. The median nerve runs alongside the brachial artery crossing the elbow joint anteriorly. The radial nerve crosses the elbow joint laterally along the lateral epicondyle, where the ulnar nerve crosses the elbow medially along the medial epicondyle.

A strong anterior force to the posterior aspect of the flexed elbow is the most common mechanism of injury in an anterior elbow dislocation.[rx] Put simply, the basic mechanism of the anterior elbow dislocation is hyperextension.

With anterior elbow dislocations, the olecranon is commonly fractured. The anterior force on the flexed elbow causes the olecranon to be levered within the olecranon fossa and fractured. The continuation of the anterior force displaces the more distal aspect of the ulna anteriorly, leaving the fractured olecranon fragment behind.[rx]

Symptoms Of Anterior Elbow Dislocations

Symptoms include:

• The child stops using the arm, which is held in extension (or slightly bent) and palm down.^[rx]
• Minimal swelling.
• All movements are permitted except supination.
• Pain on the outer part of the elbow (lateral epicondyle)
• Point tenderness over the lateral epicondyle—a prominent part of the bone on the outside of the elbow
• Pain from gripping and movements of the wrist, especially wrist extension (e.g. turning a screwdriver) and lifting movements^[rx]
• Sudden intense pain at the back of the elbow will be felt at the time of injury.
• The patient will in most cases be unable to straighten the elbow.
• Rapid swelling and bruising may start to appear. Trying to move the elbow will be painful and the back of the elbow will be very tender to touch.
• Caused by longitudinal traction with the wrist in pronation, although in a series only 51% of people were reported to have this mechanism, with 22% reporting falls, and patients less than 6 months of age noted to have the injury after rolling over in bed.
• Symptoms include pain and tenderness on the inside of the elbow. Bruising and swelling may be present for more severe injuries.
• Impact injuries causing damage to the medial ligament usually involves a lateral force (towards the outside) being applied to the forearm, placing the medial (inner) joint under stress.
• The patient presents with swelling over the lateral elbow with a limited range of motion, particularly forearm rotation and elbow extension ± elbow effusion and bruising. Pain is increased with passive rotation.
• The most reliable clinical sign is point tenderness over the radial head.
• Needs careful assessment for nerve and vascular involvement, especially with brachial artery, median and ulnar nerves.
• It is important to detect crepitation or a mechanical blockage of motion from displaced fracture fragments. This often requires aspiration of a haemarthrosis with the installation of local anesthetic for pain relief.
• If there is significant wrist pain and/or central forearm pain, there may be acute longitudinal radioulnar dissociation with disruption of the distal radioulnar joint.
• Overuse injuries of the MCL may also occur. Repetitive motions that place a lot of stress on the inner elbow can cause damage to the ligament. For example, throwers (track and field and ball sports such as baseball) are prone to this injury. Especially if the technique is poor!

Diagnosis of Anterior Elbow Dislocations

History

While obtaining the history, it is important to ask the patient if they have previously dislocated or had any history of injury to the dislocated elbow. The provider should also ask the patient if they are having any new onset of numbness, tingling, or weakness in the injured extremity as damage to neurovascular structures can be associated with anterior elbow dislocations. Neurovascular compromise can affect the urgency of reduction and operative fixation. Another important aspect before moving on to the physical evaluation is to ask if the patient has had any head trauma, loss of consciousness, or have any other areas of pain as this will influence what further workup will need to be done. Finally, each patient should be asked to provide their complete medical history, congenital deformities, and medications that can affect your diagnosis and treatment moving forward.

Physical Examination

The examiner should perform and document relevant findings, including:

• Skin integrity

  • Critical when assessing for the presence of an open fracture and/or traumatic arthrotomy
• Presence of swelling or effusion
• Comprehensive neurovascular examination

How the patient carries their arm may give clues to the diagnosis.

Bony Injuries

• Supracondylar fracture

  • Flexion type

    • Patient supports injured forearm with other arm and elbow in 90º flexion
    • Loss of olecranon prominence

  • Extension type

    • Patient hold arm at side in S-type configuration

Soft Tissue Injuries

• Elbow dislocations:

  • Posterior: abnormal prominence of olecranon
  • Anterior: loss of olecranon prominence

• Radial head subluxation

  • Elbow slightly flexed and forearm pronated resists moving the arm at the elbow

Sensory And Motor Testing Of The Median And Ulnar Nerves

Median

• Test for sensory function

  • Two-point discrimination over the tip of the index finger.

• Test for motor function

  • “OK” sign with thumb and index finger and abduction of the thumb (recurrent branch)

Ulnar

• Test for sensory function

  • Two-point discrimination of the little finger

• Test for motor function

  • Abduct index finger against resistance

Compartment Syndrome

Acute compartment syndrome can usually develop over a few hours after a serious injury. Some symptoms of acute compartment syndrome are:

• A new persistent deep pain
• Pain that seems greater than expected for the severity of the injury
• Numbness and tingling in the limb
• Swelling, tightness and bruising

Radiological Test

Radiographic studies that are necessary for all patients presenting with varying degrees of elbow trauma include:

• Anteroposterior (AP) elbow
• Lateral elbow
• Oblique views (optional, depending on fracture/injury)
• Traction view (optional, can facilitate the assessment of comminuted fracture patterns)
• Ipsilateral shoulder to wrist orthogonal views
  • Especially in the setting of high energy trauma or when exam and evaluation are limited

• Fat pad sign
  • Seen with intra-articular injuries
  • Normally, anterior fat pad is a narrow radiolucent strip anterior to humerus
  • The posterior fat pad is normally not visible
  • Anterior fat pad sign indicates joint effusion/ injury when raised and becomes more perpendicular to the anterior humeral cortex (sail sign)
  • Posterior fat pad sign indicates effusion/injury
    • In adults, posterior fat pad sign without other obvious fracture implies radial head fracture
    • In children, it implies supracondylar fracture

Pediatric Considerations

• Fractures in children often occur through unossified cartilage, making radiographic interpretation confusing
• A line of mensuration drawn down the anterior surface of the humerus should always bisect the capitellum in lateral view.
• If any bony relationship appears questionable on radiographs, obtain a comparison view of uninvolved elbow.
• Suspect nonaccidental trauma if history does not tip injury.
• Ossification centers: 1 appear: (CRITOE)
  • Capitellum 3 to 6 months
  • Radial head 3 to 5 years
  • Medial (Internal) epicondyle 5 to 7 years
  • Trochlea 9 to 10 years
  • Olecranon 9 to 10 years
  • Lateral Epicondyle

• It is essential to do bilateral radiographic imaging in pediatric cases.
• A nurse’s elbow can reduce spontaneously when the patient supinates the arm.

Advanced Imaging Sequences

Computerized tomography (CT) scans are often a consideration in the setting of comminuted fracture patterns for pre-operative surgical planning.  Magnetic resonance imaging (MRI) can be an option in the setting of soft tissue and ligamentous injury evaluation, or when suspecting stress or occult fractures.[rx][rx][rx]

Treatment of Anterior Elbow Dislocations

Initial management should always be closed reduction. The reduction can help decrease pain and swelling as well as taking pressure off of soft tissue and neurovascular structures. Anterior elbow dislocations require modification to the typical elbow reduction maneuvers.[rx]

Doctors sometimes recommend very different treatments for both tennis elbow and golfer’s elbow. According to the studies done so far, the following treatments can help:

• Rest, ice
• Physical therapy when appropriate – Eccentric exercises for lateral epicondylitis
• Braces/bandages – These are worn around the elbow or on the forearm to take the strain off the muscles.
• Injections – Injections into the elbow with various substances, such as Botox, hyaluronic acid or autologous blood (the body’s own blood).
• Extracorporeal shockwave therapy (ESWT) – A device generates shock or pressure waves that are transferred to the tissue through the skin. This is supposed to improve the circulation of blood in the tissue and speed up the healing process.
• Laser therapy – The tissue is treated with concentrated beams of light. This is supposed to stimulate the circulation of blood and the body’s cell metabolism.
• Stretching and strengthening exercises: Special exercises that stretch and strengthen the muscles of the arm and wrist.
• Manual therapy – This includes active and passive exercises, as well as massages.
• Ultrasound therapy – The arm is exposed to high-frequency sound waves. This warms the tissue, which improves the circulation of blood.
• Transcutaneous electrical nerve stimulation (TENS) – TENS devices transfer electrical impulses to the nervous system through the skin. These are supposed to keep the pain signals from reaching the brain.
• Acupuncture – The acupuncture needles are inserted into certain points on the surface of the arm. Here, too, the aim is to minimize the perception of pain.
• Cold – The elbow is regularly cooled with ice packs.
• Massages –A massage technique called “transverse friction massage” is often used to treat tennis elbow and golfer’s elbow. It is applied to the tendons and the muscles, using the tips of one or two fingers.

Medication

• Conscious sedation is often necessary to achieve reductions
• Painkillers – especially non-steroidal anti-inflammatory drugs (NSAIDs).
• Injections – Steroid injections.
• Ibuprofen – 600 to 800 mg (pediatric: 5 to 10 mg/kg) PO TID
• Naprosyn – 250 to 500 mg (pediatric: 10 to 20 mg/kg) PO BID
• Tylenol with codeine – 1 or 2 tabs (pediatric 0.5 to 1 mg/kg codeine) PO: do not exceed acetaminophen 4g/24 hours
• Morphine sulfate – 0.1 mg/kg IV
• Hydromorphone 5 mg/acetaminophen 300mg
• Hydrocodone/acetaminophen – 1 to 2 tabs PO

Attritional injuries management modalities

Most of these injections contain one of the following active ingredients. These include but are not limited to[rx][rx][rx]:

• Corticosteroid injection – when applicable
• Platelet-rich plasma (PRP) considerations – 2016 study noted efficacy in managing UCL insufficiency
• Steroids: reduce inflammation. Studies show that steroid injections can temporarily relieve pain. But there is also evidence that they can disrupt the healing process: People who were first given several steroid injections had more pain after a few months than people who didn’t receive any steroid injections. Frequent steroid injections carry the risk of tissue dying (atrophy), for instance, leaving a visible mark on the elbow.
• Hyaluronic acid – A substance made by the body, found in tissue and joints. It is typically used to treat osteoarthritis. One study suggests that hyaluronic acid might be effective in the treatment of tennis elbow. But further research is needed to assess its pros and cons.
• Botox – inhibits the sending of signals between the nerve cells. This has a paralyzing effect on the muscles. According to studies done on this so far, Botox can relieve the pain just a little at most. Also, Botox injections can have side effects like partial paralysis in the fingers that can last several weeks.
• Autologous blood injections – Blood is taken from a vein in the arm and then injected into the elbow. This blood may be treated in different ways before it is injected. One common form of treatment with autologous blood is called platelet-rich plasma (PRP) therapy. It involves separating the blood into its various elements in a centrifuge. Then a concentrated solution of blood platelets is injected into the elbow. There is no evidence that treatment using autologous blood is effective.

In most cases, the patient will need intravenous sedation to relax the muscles allowing for proper manipulation for reduction. Once the patient is adequately sedated, traction should be applied to the arm. Ideally, there are two providers pulling traction, one on the forearm with the other pulling counter traction on the humerus. For an anterior elbow dislocation, the reduction is performed by flexing the elbow while pulling traction and applying a downward force on the proximal forearm.[rx] After reduction, the stability of the elbow should be tested with range of motion and varus and valgus stress. An unstable elbow after reduction is more likely to need operative intervention than a stable elbow. Neurovascular status of the extremity should also be reevaluated after reduction. A posterior, long arm splint should then be applied with the elbow flexed at ninety degrees. After the splint is in place, post-reduction radiographs should be taken to ensure the elbow is adequately reduced.

The patient should remain splinted and follow up in five to ten days from the time of reduction.[rx] At that point, the patient’s elbow should be reexamined for stability, neurovascular status, and radiographically. If the elbow remains unstable or demonstrates a fracture on x-ray, the patient will require operative intervention. If the elbow is stable on exam, then the patient may begin early range of motion to prevent stiffness. Elbows tend to get stiff if they are immobilized for more than three weeks. After about twenty-one days of immobilization, it becomes very difficult for the patient to regain full range of motion of their elbow.

References