Elbow dislocation

The elbow is the second most commonly dislocated joint after the shoulder. A fall on an outstretched hand is the usual mode of injury. Complex elbow dislocations have an associated fracture, while simple elbow dislocations do not. Clinical features include pain and swelling of the joint and an inability to flex/extend the elbow. Examination reveals a loss of the triangular orientation between the medial and lateral epicondyles of the humerus and the olecranon process of the ulna. X-rays of the elbow joint confirm a dislocation and may show a positive fat pad sign. Simple elbow dislocations can be managed conservatively with closed reduction and immobilization. Complex elbow dislocations require surgical intervention with open reduction and internal fixation. Complications of elbow dislocation include joint instability/contractures and heterotopic ossification.

Radial head subluxation (nursemaid elbow) is discussed in another article.

• Second most frequently dislocated joint (after the shoulder joint)
• Sex: ♂ > ♀
• Peak incidence: 10–20 years

References:^[1]

Epidemiological data refers to the US, unless otherwise specified.

• Trauma
  • Fall on an outstretched hand (most common) → posterior elbow dislocation
  • A posterior, direct trauma to a flexed elbow → anterior elbow dislocation
  • Medial/lateral trauma to the elbow → medial/lateral elbow dislocation
  • High impact trauma to the elbow → divergent elbow dislocation

• Anatomical classification
  • Posterior dislocation (most common)
  • Anterior dislocation
  • Medial dislocation
  • Lateral dislocation
  • Divergent dislocations (rare)
• Presence of co-existent fractures
  • Simple dislocation
  • Complex dislocation

• Pain, swelling of the elbow
• Limited range of motion: inability to flex or extend the elbow
• Elbow deformity
• Limb length discrepancy
• Nerve injury (up to 10% of cases)
  • Ulnar nerve palsy
  • Median nerve palsy
  • Radial nerve palsy or posterior interosseous neuropathy (depending on site of injury)
• Brachial artery injury (very rare)

References:^[2][3]

• Physical examination
  • Signs of fracture
  • Neurovascular deficits
• X-ray of the elbow joint: anteroposterior and lateral views to confirm dislocation and exclude fracture
  • Posterior fat pad sign: seen in patients with concomitant fractures (usually of the humerus/radial head) ^[4]
  • Radiocapitellar line
    • On a lateral x-ray of the elbow joint, an imaginary line drawn through the center of the neck of the radius should pass through the center of the capitellum of the humerus.
    • If an elbow dislocation is present, the line does not intersect the capitellum.
• CT scan of the elbow joint: indicated only if a complex elbow dislocation is suspected to evaluate the extent of associated fractures

• Conservative management
  • Indication: simple elbow dislocation (no fracture)
  • Procedure: closed reduction
  • Signs of successful reduction
    • Return of the normal triangular orientation of the 3 bony prominences of the elbow
    • Decrease in pain
  • Post-reduction x-rays are obtained
  • Neurovascular status should be rechecked
  • Immobilization of the relocated elbow in a posterior splint or brace, in pronation and 90° flexion for 7–10 days
• Surgical intervention
  • Indication: complex elbow dislocation (concomitant fracture); failed closed reduction; joint instability post-reduction; vascular injury
  • Procedure
    1. Closed reduction of elbow
    2. Open reduction and internal fixation of the fractured segments and repair of the torn medial and/or lateral collateral ligaments of the elbow
  • After surgery
    • Obtain elbow x-rays
    • Check neurovascular status of the forearm and hand
  • Immobilization of the elbow in a posterior splint or brace in pronation and 90° flexion for 3 weeks ^[5]
• Rehabilitation: range of motion exercises (active and passive)

• See “Complications of fractures.”
• Avascular necrosis of the radial head (in concomitant radial head fractures)

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