Elbow Dislocation: Reduction Techniques, Diagnosis and Complications

Elbow dislocation is the second most common large joint dislocation in adults (up to 25%) and the most common large joint dislocation in children
It mostly affect younger patients aged 10-20 years due to sports injuries and high energy injuries (e.g. road traffic accidents)
That is because, the elbow is a highly stable joint, it requires a considerable amount of force to be dislocated

Anatomy

Elbow is a hinge type of synovial joint
It is formed by the articulation of the capitulum and trochlea of the distal humerus with the radial head and trochlear notch of the radius and ulna respectively.
The articular surfaces of these bones are almost in full contact with each other leading to higher stability of the elbow joint
The joint capsule of the elbow surrounds the elbow joint and provide more stability

Elbow joint is furtherly stabilized by ligaments, those include:
- radial collateral ligament: connect lateral epicondyle of the humerus with the annular ligament
- Annular ligament of the radius: encircles the radial head into the ulnar notch
- Ulnar collateral ligament: connects medial epicondyle of the humerus to the coronoid process and olecranon of the ulna and it contain two bands anterior and posterior

Muscles around the elbow joint also help in stabilization (common flexors, common extensors, brachialis, triceps …)
All of these factors make the elbow a highly stable joint but sometimes dislocation occur

When elbow dislocation occurs, this may lead to:
- Bony injury (radial head fracture, coronoid process fracture)
- Capsular injury
- Ligament injury (especially medial collateral ligament)
- Muscle injury
In simple dislocations, there will be no bone injury but the capsule and ligaments will be injured, however the elbow will be reduced and it will still be stable after reduction
In complex elbow dislocations, there will be bone injury in association with the capsular and ligamentous injuries; radial head being the most common associated fracture and coronoid process of the ulna being second most common, in these injuries were there is elbow dislocation and only one fracture (either radial head or coronoid process) then elbow will also be stable after reduction in most cases
If all of these three come together (elbow dislocation + radial head fracture + coronoid process fracture) then this is called terrible triad injury and in this case elbow will be unstable after reduction with bad prognosis (recurrent dislocations and osteoarthiritis)

Elbow dislocations are classified according to the direction of displacement of the forearm relative to the arm into posterior (90%), anterior, medial, lateral and convergent
Elbow dislocations also classified into simple and complex, simple is without associated fracture and complex is with associated fractures (e.g. coronoid process fracture or radial head fracture)

Ulnar coronoid process is classified according to Regan and Morrey classification
Regan and Morrey classifies coronoid process fractures according to the size of the fractured fragment into:
Type I: fracture of the tip of the coronoid process (small fragment)
Type II: fracture of < 50% coronoid process fragment
Type III: fracture of > 50% coronoid process fragment

Symptoms
- Patient present with elbow pain and deformity, patient elbow is usually held in slight flexion and supported by the other hand
Physical examination
- Look
  - Elbow swelling
  - There might be ecchymosis around the elbow
  - Deformity is obvious
- Feel
  - there is tenderness on pressure around the elbow, and bony landmarks (olecranon and epicondyles) maybe abnormally placed
  - Check radial pulse and compare with other hand to make sure no vascular injury is sustained
  - Neurological examination will reveal Ulnar nerve injury in most cases
- Move
  - Patient refuse to move their elbow

Plain radiographs are enough for diagnosis, CT scan maybe required for surgical planning and assessment
AP and lateral elbow x rays shows the dislocation well, radiocapitellar line is drawn to make it easier to spot the dislocation
The challenge with plain radiographs is to identify the associated injuries
The dislocation direction is described, also the associated fractures and injuries should also be described in the report

In the x ray, the dislocation is divergent, in which there is ulnohumeral, radiohumeral and proximal radioulnar joints all dislocated

Simple elbow dislocations are treated non operatively with closed reduction
Elbow closed reduction maneuver 1:
- Patient is placed supine and procedural sedation is usually required
- Ask an assistant to provide counter traction at the proximal humerus
- Patient wrist is held with one hand while the dislocated elbow is manipulated from the underside by the other hand
- Reduce any medial/ lateral displacement first by the hand under the elbow
- Then apply traction using both hands with flexion of patient elbow to 90 degrees
Elbow closed reduction maneuver 2:
- Ask assistant to hold patient wrist and apply traction with flexion
- You hold and push the olecranon distally, anteriorly and medially using your thumbs
Reduction is confirmed by assessing the full range of motion and varus and valgus stress application while doing that
After that, the elbow is immobilized in above elbow backslab with 90 degrees of flexion for 1 week and then exercises started
Repeat radiographs to make sure reduction is good and joint is congruent (joint space equal along the articular surfaces) and repeat neuro examination
Indications of operative treatment
- Failure of closed reduction
- Joint instability
- Complex fracture dislocations => requires reduction and management of the fractures and damaged soft tissues
- Operative management of elbow injuries usually carries poor prognosis due to secondary osteoarthritis

Nerve injury
- Ulnar nerve: most common to be injured with posterior dislocations (neuropraxia)
- Median nerve: maybe entrapped during closed reduction of posterior dislocations
- Radial nerve
Brachial artery: with anterior dislocations => requires emergency surgery to repair the artery
Stiffness: loss of 20-30 degrees of terminal extension of the elbow due to prolonged immobilization
Heterotopic ossification: lead to more stiffness
Recurrent dislocation: most commonly caused by radial collateral ligament incompetence and fracture dislocation
Secondary osteoarthritis