Paediatric Radial Neck, Olecranon and Elbow Dislocation Injuries

These injuries sit close together anatomically and clinically. A child can present with a radial neck fracture, olecranon fracture or elbow dislocation, but the surgeon must actively search for the combined pattern. A radial neck fracture can accompany elbow dislocation or Monteggia injury. An olecranon fracture can be part of proximal ulna instability. A reduced elbow dislocation can hide an incarcerated medial epicondyle or nerve entrapment.

Common mechanisms

Radial neck and proximal radius

The radial head ossifies in childhood and the radial neck behaves differently from the adult radial head. The periosteal sleeve and physis contribute to remodelling, but severe angulation, translation and mechanical block to rotation are poorly tolerated. The posterior interosseous nerve passes near the proximal radius as it enters the supinator, so nerve function must be documented before and after injury manipulation.

Olecranon and proximal ulna

The olecranon is the triceps insertion and part of the greater sigmoid notch. Treatment depends on whether the articular surface and extensor mechanism remain functional. In a child, the olecranon apophysis and proximal ulna alignment can make the injury look deceptively small, but any proximal ulna deformity should raise concern for radiocapitellar instability.

Elbow dislocation and medial epicondyle

In children, the medial collateral ligament is attached to the medial epicondylar apophysis. A dislocation can therefore avulse the medial epicondyle rather than rupture the ligament midsubstance. During spontaneous or closed reduction, the fragment can become trapped in the ulnohumeral joint. The ulnar nerve runs posterior to the medial epicondyle and the median nerve can rarely be entrapped after dislocation.

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The common theme is failure of the paediatric elbow ring. The visible fracture may be only one part of the instability pattern.

The treatment logic follows the biology. Young children remodel some angulation, but remodelling does not reliably correct severe translation, blocked forearm rotation, joint incongruity, incarcerated fragments or extensor mechanism failure. These are the findings that move treatment from observation to reduction or fixation.

Classification should help communication and treatment, not replace clinical judgement.

History

Ask enough to identify the injury pattern and urgency:

• Mechanism: fall, valgus load, direct posterior blow, dislocation event or high-energy trauma.
• Time from injury and whether the elbow was reduced before assessment.
• Pain location: radial head/neck, olecranon, medial epicondyle or diffuse elbow pain.
• Mechanical block: inability to pronate or supinate suggests radial neck displacement or intra-articular block.
• Neurological symptoms: numbness, paraesthesia, weakness, clawing, inability to extend fingers or thumb.
• Vascular symptoms: cold hand, colour change, severe swelling or escalating analgesic requirement.
• Previous elbow injury, hyperlaxity, sporting demand and hand dominance.

Examination sequence

Nerve and vessel tests

What to request

Order imaging that answers the surgeon's questions, not just "elbow X-ray":

• AP and true lateral elbow radiographs: mandatory first-line views.
• Radiocapitellar or oblique view: helpful if radial neck alignment or capitellum relationship is unclear.
• Forearm AP and lateral including wrist and elbow: request when there is ulna pain, deformity, plastic bowing or any concern for Monteggia variant.
• Post-reduction AP and lateral radiographs: mandatory after elbow dislocation reduction.
• Comparison elbow radiographs: useful when ossification centres make medial epicondyle or trochlear interpretation difficult.
• CT: use for complex fracture-dislocation, articular olecranon fracture planning, incarcerated fragment uncertainty or surgical planning.
• MRI or ultrasound for nerve entrapment: not routine, but useful when neurological symptoms persist or median nerve entrapment is suspected.

How to read the films

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Radial neck reduction ladder

The principle is to reduce the radial neck with the least soft-tissue stripping that gives a stable, congruent, mobile elbow.

Olecranon fixation

Use a posterior approach centred on the olecranon. The operation is directed by the fracture pattern:

• Simple transverse displaced fracture: reduce articular surface anatomically; fixation may be suture tension band, wire tension band, intramedullary screw or combined construct depending size and maturity.
• Comminuted or oblique pattern: plate fixation may provide better control than tension band alone.
• Skeletally immature child: minimise physeal/apophyseal injury and choose fixation that avoids unnecessary hardware prominence.
• Associated instability: confirm radiocapitellar congruity and ulna alignment after fixation.

Key steps:

1. Position supine or lateral with image intensifier access.
2. Mark olecranon, proximal ulna, medial epicondyle and ulnar nerve course.
3. Posterior incision; protect skin flaps and avoid unnecessary ulnar nerve handling unless the approach extends medially.
4. Clear fracture haematoma without stripping soft tissue unnecessarily.
5. Reduce the articular surface and confirm on AP/lateral fluoroscopy.
6. Choose fixation based on pattern: suture tension band, wire tension band, screw, plate or hybrid.
7. Test elbow motion and radiocapitellar alignment before closure.
8. Immobilise initially, then start motion when fixation and soft tissues allow.

Elbow dislocation with incarcerated medial epicondyle

This is a surgical problem because the fragment blocks joint restoration and carries the medial collateral ligament attachment.

1. Position supine with the arm on a hand table.
2. Mark the medial epicondyle, olecranon and ulnar nerve.
3. Use a medial approach centred over the medial epicondyle.
4. Identify and protect the ulnar nerve; transpose only if needed for exposure, instability or nerve symptoms.
5. Open the joint enough to extract the incarcerated fragment.
6. Reduce the medial epicondyle to its origin and fix with screw, K-wire or suture construct according to fragment size and skeletal maturity.
7. Confirm ulnohumeral and radiocapitellar congruity on AP and lateral images.
8. Check elbow stability through a safe arc.
9. Repeat and document median, ulnar and posterior interosseous nerve function post-operatively.

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The elbow becomes stiff quickly, but unstable fixation or an unrecognised associated injury is worse than a short period of protection. Rehabilitation therefore depends on the stability achieved.

Parents should understand that the goal is not simply bone healing. The child also needs a congruent elbow, recovering motion, intact nerve function and no missed associated injury.