Courtesy: Kaye Wilkins MD
Prof Lynn Staheli

 

Radial Neck and Olecranon Fractures in Children

Radial Neck Fractures

Basic concepts

• Most pediatric radial fractures occur at the radial neck (metaphysis), the weakest part of the proximal radius.
• Radial head ossification appears at 3 to 4 years of age.
• Ossification is complete by 6 to 7 years.
• A bipartite radial head may mimic a fracture.

Biomechanics

• The radiocapitellar joint is highly congruent.
• Translocation of the radial head produces a cam effect, limiting forearm rotation, particularly pronation.
• Even minimal displacement can significantly impair function.

Mechanism of injury

Primary injuries

• Fall on an outstretched hand.
• Elbow extension with valgus stress causing compression of the radial head against the capitellum.

Associated injuries

• Monteggia fracture dislocation, particularly Type II.
• Elbow dislocation.

Patterns of displacement

• Valgus compression causing angulation with or without translocation.
• Elbow dislocation may produce anterior displacement initially and posterior displacement after reduction.

Assessment

• Measure fracture angulation.
• Assess radial head translocation.
• Examine forearm pronation and supination.
• Functional motion requires approximately 50 degrees each of pronation and supination.

Acceptable limits

• Angulation less than 30 degrees is acceptable.
• Angulation between 30 and 60 degrees usually requires closed reduction.
• Angulation greater than 60 degrees often requires surgical treatment.
• Translocation less than 3 mm is generally acceptable.
• Greater translocation should be corrected to preserve rotation.

Treatment

Nonoperative treatment

• Immobilization for minimally displaced fractures.

Closed reduction

• Israeli (Kaufman) technique.
• Elbow flexed to 90 degrees.
• Direct pressure over the radial head.
• Forearm pronation helps close the metaphyseal gap and reduce the fragment.

Percutaneous techniques

• Direct reduction using a K wire or elevator.
• Retrograde intramedullary nailing (Metaizeau technique).
• Rotation of the intramedullary nail assists fracture reduction.

Open reduction

• Reserved for failed closed or percutaneous reduction.
• Indicated for displaced Salter Harris Type III fractures.
• Higher risk of complications.

Complications

• Loss of forearm rotation.
• Avascular necrosis.
• Malunion.
• Nonunion.
• Radial head overgrowth.
• Radioulnar synostosis.
• Heterotopic ossification.

Clinical pearls

• Always evaluate the ulna for a Monteggia injury.
• Assess the lateral collateral ligament complex.
• Severe displacement increases the risk of avascular necrosis.
• Look carefully for associated injuries.

Olecranon Fractures

Ossification

• Olecranon ossification begins at approximately 8 years of age.
• Two ossification centers are present: articular and traction centers.

Mechanism based classification

Flexion (tension) injury

• Triceps pull causes posterior displacement.
• Associated with loss of active elbow extension.
• Posterior swelling and a palpable gap may be present.

Extension injury

• Failure of the anterior cortex with an intact posterior cortex.
• Stable injury suitable for immobilization in elbow flexion.

Shear injury

• Caused by direct trauma to a flexed elbow.
• Radius and ulna displace together.

Greenstick injury

• May be associated with radial neck fractures.
• May occur with medial epicondyle fractures.
• May accompany Monteggia lesions.

Treatment

Nonoperative treatment

• Long arm cast for minimally displaced fractures.

Operative treatment

• Restore the articular surface.
• Restore the extensor mechanism.
• Tension band wiring.
• Screw fixation with tension band augmentation.
• Absorbable suture fixation may be advantageous in children.

Complications

• Loss of elbow extension.
• Prominent hardware.
• Nonunion.
• Residual deformity affecting radiocapitellar alignment.

Exam Pearls

• Radial neck fractures are typically valgus compression injuries.
• Evaluate both angulation and translocation when planning treatment.
• The Israeli (Kaufman) technique is a commonly tested closed reduction method.
• In Monteggia injuries, reduce and stabilize the ulna first.
• Open reduction of radial neck fractures has the highest complication rate.
• Flexion type olecranon fractures commonly present with loss of active elbow extension.
• Tension band fixation converts tensile forces into compressive forces across the fracture site.