Elbow dislocation — Medicine Library

Summary

Elbow dislocation is an atypical separation of the radial, ulnar, and humeral joint surfaces. A posterior dislocation of the elbow is common and is typically caused by a fall on an outstretched hand. Clinical features include pain, swelling, visible deformity, and reduced active range of motion of the joint. An elbow dislocation is classified as complex if there is an associated fracture. Diagnosis is confirmed with radiography. Elbow dislocations without an associated fracture are managed conservatively with closed reduction and immobilization. Complex elbow dislocations require surgery with open reduction and internal fixation. Complications of elbow dislocation include nerve injury, brachial artery injury, joint instability, and posttraumatic stiffness.

See “Radial head subluxation” for information on partial dislocation of the head of the radius at the radio-humeral joint.

Epidemiology

The second most frequently dislocated joint (after the shoulder joint) [1]
Sex: ♂ > ♀ [2]
Peak incidence: 10–20 years of age [3]

Epidemiological data refers to the US, unless otherwise specified.

Etiology

Elbow dislocations are most commonly caused by sports-related trauma (e.g., falls while cycling, skating, or performing gymnastics). [3]

A fall on an outstretched hand (most common) causes posterior elbow dislocation.
Posterior, direct trauma to a flexed elbow causes anterior elbow dislocation.
Medial or lateral trauma to the elbow causes medial or lateral elbow dislocation.
High-impact trauma to the elbow causes divergent elbow dislocation.

Classification

Elbow dislocations are classified by anatomical position and complexity.

Anatomical position [3]

The type of dislocation is defined by the position of the ulna relative to the olecranon.

Posterior dislocation (most common)
Anterior dislocation
Medial dislocation
Lateral dislocation
Divergent dislocations (rare)

Complexity [4]

Simple dislocation: no concomitant fracture
Complex
dislocation: one or more associated
fractures
- Radial head
- Ulnar coronoid process
- Terrible triad of the elbow: fractures of both the radial head and coronoid process and disruption of the medial collateral ligament

Classification of elbow dislocation by anatomical position

Clinical features

Pain and/or swelling of the elbow
Reduced active
range of motion
[3]
- Posterior dislocation: Patient typically holds elbow at 45° of flexion.
- Anterior dislocation: Patient typically holds elbow in extension.
Visible deformity
[3]
- Prominent olecranon
- Posterior dislocation: shortened forearm
- Anterior dislocation: lengthened forearm
Anesthesia,
paresthesias, and/or
weakness
[3]
- Ulnar nerve palsy and/or median nerve palsy (most common)
- Radial nerve palsy and/or posterior interosseous neuropathy (uncommon)
Signs of vascular injury and/or signs of acute limb ischemia (rare)

If the elbow has spontaneously reduced before examination, patients may present with only swelling, pain, and/or tenderness. [1]

Diagnosis

Clinical evaluation [1]

Visual inspection
- Assess for gross deformities (e.g., olecranon prominence, forearm shortening).
- Evaluate skin for laceration, tearing, bruising, and/or tenting.

Neurovascular examination
- Assess pulses in the brachial artery, radial artery, and ulnar artery.
- Test capillary refill time.
- Evaluate for median nerve injury , radial nerve injury , and ulnar nerve injury.

Intact distal pulses do not exclude brachial artery injury. Obtain arteriography and consult vascular surgery if arterial injury is suspected. [1]

Pinch sign (anterior interosseous syndrome) Hand of benediction Radial nerve neuropathy Ulnar nerve neuropathy

Imaging [1][5]

X-ray of the elbow

Views
[3]
- Anteroposterior and lateral: all patients
- Oblique: patients with suspected medial epicondyle fracture (most common in pediatric patients) [3]
Findings
- Type of dislocation (i.e., position of ulna relative to olecranon)
- Associated fractures: typically radial head, ulnar coronoid, and/or distal humerus
- Posterior fat pad sign: suggests a fracture of the humerus and/or radial head [6]
- Radiocapitellar line: a line drawn along the axis of the radial neck on a
  lateral elbow x-ray
  
  Normally passes through the center of the capitellum
  
  Misalignment suggests elbow dislocation and/or radial head subluxation.

Radiograph of normal elbow Posterolateral elbow dislocation $Radial head fracture$ Fracture through olecranon physis $Anterior and posterior fat pad signs in supracondylar fracture$ Radiocapitellar line

Advanced testing

CT
elbow: may be used in situations where additional diagnostic detail is required
- Detection of subtle fractures despite negative or inconclusive x-ray
- Evaluation of complexity (e.g., intra-articular involvement, comminution) or injury extent of known fractures
- For surgical planning
Arteriography: to evaluate for suspected brachial artery injury (e.g., thrombosis, laceration)

**Pinch sign (anterior interosseous syndrome)**
The anterior interosseous nerve is a pure motor branch of the median nerve. It supplies the flexor pollicis longus, the radial half of the flexor digitorum profundus (and the pronator quadratus).
Pinch sign: an inability to flex the DIP of the index finger and IP joint of the thumb when asked to make an “OK” sign that is caused by a lesion or entrapment of the anterior interosseous nerve

© AMBOSS

**Hand of benediction**
An inability to flex the index and middle fingers at the MCP and IP joints and an inability to oppose the thumb.
The hand of benediction is an active sign and is only seen when the patient is asked to make a fist. It indicates a paralysis of the thenar muscles (except the adductor pollicis), the flexor digitorum superficialis, and the radial half of the flexor digitorum profundus caused by a proximal lesion of the median nerve (above the elbow).
Also depicted is atrophy of the thenar muscles, which is seen in chronic median nerve palsy.

© AMBOSS

**Radial nerve neuropathy**
Motor deficits:
- Wrist drop: inability to extend (dorsiflex) the wrist
- Inability to extend the fingers at the MCP joints
Sensory deficits:
- Dorsal aspect: radial 2½ fingers (less commonly, 3½ fingers), excluding the tips of the 2^nd and 3^rd fingers. The 1^st web space is the autonomous sensory zone of the radial nerve and is highlighted in red.
- Palmar aspect: the radial border of the thumb
Proximal lesion: complete loss of motor and sensory function
Distal lesion (radial tunnel syndrome): partial loss of motor function; preservation of sensory function

© AMBOSS

**Ulnar nerve neuropathy**
Motor deficits:
- Claw hand: The 4^th and 5^th joints are hyperextended at the MCP and flexed at the IP joints at rest (neutral position).
- Froment sign: The patient is asked to grasp a piece of paper between the thumb and the index finger. When the examiner tries to pull the paper away, the thumb flexes at the IP joint because the flexor pollicis longus (supplied by the median nerve) compensates for the paralyzed adductor pollicis (supplied by the ulnar nerve).
Also depicted here is hollowing of the intermetacarpal spaces and the 1^st web space due to the atrophy of the interossei, which is seen in chronic ulnar nerve palsy.
Sensory deficits:
- Dorsal aspect: ulnar 2½ fingers (less commonly, 1½ fingers), excluding the tips of the 3^rd and 4^th fingers
- Palmar aspect: ulnar 1½ fingers
Proximal lesion: complete loss of motor and sensory functions
Distal lesion: complete loss of motor function; preservation of sensory function

© AMBOSS

**Radiograph of normal elbow**
X-ray elbow (left: lateral view; right: AP view)
There is no evidence for fracture or dislocation. The anterior fat pad (white overlay on left image) is not abnormally elevated. No posterior fat pad is visible.
C: capitulum (also highlighted by green dotted line); CP: coronoid process; H: humerus; LE: lateral epicondyle; ME: medial epicondyle; OP: olecranon process (also highlighted by white line); RH: radial head; R: radius; T: trochlea (also highlighted by red-dotted line); U: ulna

Source: “Coude fp.PNG” by MB, Wikimedia Commons, licensed under CC BY 2.5. The supplementary image with overlays of relevant areas was adapted from the image mentioned above (© AMBOSS).

**Posterolateral elbow dislocation**
X-ray elbow (left: AP view; right: lateral view)
A posterolateral dislocation is seen (white arrows), with elevation of the posterior fat pad (red overlay) caused by a joint effusion. The dislocation is considered simple since there is no associated fracture.
Elbow dislocations may be posterolateral, posteromedial, posterior, anterior, medial, or lateral. The majority of dislocations are posterolateral or posterior. In anatomical position, the radius is located lateral to the ulna.
Green overlay: trochlear notch

Source: “Elbow2010D” by James Heilman, MD, Wikimedia Commons, licensed under CC BY-SA 3.0. Modifications: images merged (above info relates to AP image); lateral: Elbow1, https://commons.wikimedia.org/wiki/File:Elbow1.jpg, same copyright and author as AP. The supplementary image with overlays of relevant areas was adapted from the image mentioned above and licensed under CC BY-SA 3.0.

**Radial head fracture**
X-ray left elbow (left: AP view; right: lateral view)
The radial head fracture shows intraarticular extension and slight distraction (widening) at the fracture line (red overlay).

Source: © IMPP

**Fracture through olecranon physis**
X-ray right elbow (lateral view) of an adolescent
A fracture through the physis (growth plate) is accompanied by physeal widening (white dashed outline) and displacement of the olecranon process (green overlay).

Source: “Olecranon Fracture.jpg” by Benoudina samir, Wikimedia Commons, licensed under CC BY-SA 3.0. The supplementary image with overlays of relevant areas was adapted from the image mentioned above and licensed under CC BY-SA 3.0.

**Anterior and posterior fat pad signs in supracondylar fracture**
X-ray (lateral view) of a child's elbow
Posterior displacement of the capitulum. Both anterior and posterior fat pad signs can be seen as areas of decreased radiodensity (arrows). The anterior fat pad sign is also called "sail sign" because of its distinctive shape.

Source: “Sailsign” by James Heilman, MD, Wikimedia Commons, licensed under CC BY-SA 3.0.

**Radiocapitellar line**
A straight line drawn down the neck of the radius should intersect the capitellum. If it does not, there is a dislocation of the radial head.

© AMBOSS

Treatment

Initial management

Follow the ABCDE approach for patients with polytrauma.
Manage acute pain while initiating steps for immediate closed reduction (e.g., preparation for procedural sedation).
Consult orthopedics urgently if surgery is required.

Closed reduction of a posterior elbow dislocation [3][5]

Procedure

Indication: uncomplicated simple posterior elbow dislocation
Preparation
- Obtain informed consent.
- Administer procedural sedation and analgesia.
- Position the patient for the procedure (typically prone or sitting).
Technique
1. Flex the elbow to 90° and pronate (preferred) or supinate the forearm.
2. Apply slow axial traction to the forearm while applying counter traction to the middle or distal humerus.
3. Simultaneously apply direct pressure on the posterior aspect of the olecranon.
4. Monitor for signs of successful reduction.
  - Palpable clunk
  - Normal triangular orientation of the three bony prominences of the elbow
  - Reduced pain
5. Verify the stability of relocation by moving the arm through a range of motion.
6. Obtain repeat x-rays to verify correct positioning.
7. Repeat neurovascular examination.

Postreduction

Elbow
immobilization
- Use a posterior long arm splint or brace.
- Place the elbow at 90° flexion with the forearm in slight pronation.
- Reassess vascular status after the splint is applied.
- Maintain immobilization for 5–10 days. [1][5]
POLICE principle
Range of motion exercises (after a period of immobilization)
Orthopedic follow-up (within 1 week) [3]

Closed reduction of uncomplicated elbow dislocation Supination and pronation Arm/elbow brace

Surgery [7]

Indications
- Complex elbow dislocation
- Failed closed reduction
- Joint instability postreduction
- Vascular injury
- Compartment syndrome
Techniques
- Open reduction and internal fixation of the fracture
- Tenodesis and/or ligament repair

**Supination and pronation**
Right forearm; ventral view
Supination is an external rotational movement of the forearm that occurs at the proximal and distal radioulnar joints. When the forearm is in the supine position, the radius and ulna lie parallel to each other and the palm faces up. The supinator and biceps brachii (not shown here) are the supinators of the forearm.
Pronation is an internal rotational movement of the forearm that occurs at the proximal and distal radioulnar joints. When the forearm is in the prone position, the radius and ulna form an X shape and the palm faces down. The pronator quadratus and pronator teres (not shown here) are the pronators of the forearm.
The interosseous membrane stabilizes the proximal and distal radioulnar joints during pronation and supination.

© AMBOSS

**Closed reduction of uncomplicated elbow dislocation**
There are various techniques that can be used in a number of combinations. Administration of analgesics prior to the procedure is advisable.
This illustration shows a common approach in which the patient lies down on a stretcher in a supine position with one physician on each side (A).
One of the physicians raises the affect arm, clasping the elbow from both sides with both thumbs placed on the olecranon. The elbow is flexed to 90 degrees. The second physician then gently applies axial traction in the distal direction. At the same time, the first physician carefully applies pressure on the olecranon (to guide it back into position) and simultaneously applies gentle counter-traction to stabilize the position of the humerus (B).
Depending on the injury, the patient's condition, and possible concomitant injuries, this procedure can also be conducted with the forearm supinated rather than a pronated.
If neurovascular damage and/or fractures are present or suspected, additional diagnostic steps and different therapeutic measures are necessary.

© AMBOSS

**Arm/elbow brace**
The angle between the brace's upper and lower parts is adjustable at the elbow joint.

Source: “Terminator-esque arm brace” by Juhan Sonin, flickr, licensed under CC BY 2.0.

Complications

Recurrent dislocation and instability
Posttraumatic stiffness (especially after prolonged immobilization)
Posttraumatic arthritis and/or soft tissue ossification
Brachial artery injury and/or vascular compromise
Peripheral nerve injury
Acute compartment syndrome
See also “Complications of fractures.”

We list the most important complications. The selection is not exhaustive.

References

Walls R, Hockberger R, Gausche-Hill M, Erickson TB, Wilcox SR. "Rosen's Emergency Medicine 10th edition- Concepts and Clinical Practice E-Book". Elsevier Health Sciences. (2022). ISBN: 9780323757904
Reichert ILH, Ganeshamoorthy S, Aggarwal S, Arya A, Sinha J. "Dislocations of the elbow – An instructional review". J Clin Orthop Trauma. 21. :101484. (2021)
Gottlieb M. "Managing Elbow Dislocations". Ann Emerg Med. 80(5). :460-464. (2022)
Mühlenfeld N, Frank J, Lustenberger T, Marzi I, Sander AL. "Epidemiology and treatment of acute elbow dislocations: current concept based on primary surgical ligament repair of unstable simple elbow dislocations". Eur J Trauma Emerg Surg. 48(1). :629-636. (2020)
Roberts JR. "Roberts and Hedges' Clinical Procedures in Emergency Medicine and Acute Care". Elsevier. (2018). ISBN: 9780323354783
Pandian NG, Kim JK, Arias-Godinez JA, et al. "Recommendations for the Use of Echocardiography in the Evaluation of Rheumatic Heart Disease: A Report from the American Society of Echocardiography". J Am Soc Echocardiogr. 36(1). :3-28. (2023)
Breulmann FL, Lappen S, Ehmann Y, et al. "Treatment strategies for simple elbow dislocation - a systematic review". BMC Musculoskelet Disord. 25(1). (2024)