Elbow dislocation

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.

• 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.

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 media or lateral elbow dislocation.
• High impact trauma to the elbow causes divergent elbow dislocation.

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

• 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]

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]

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.

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)

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]

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

• 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.