Paediatric Radial Neck Fracture Management

Classification — Judet System

The Judet classification is the standard system for paediatric radial neck fractures. It is based on the degree of angulation (tilt) of the radial head relative to the radial neck axis, measured on the lateral radiograph.

Non-Operative Management

Indications for Non-Operative Treatment

• Judet Type I (angulation less than 30 degrees)
• Judet Type II with acceptable reduction after closed manipulation (residual less than 30 degrees in a child under 10 years)
• Children with medical comorbidities where the risks of anaesthesia outweigh the benefit of anatomic reduction

Technique

• Above-elbow cast or backslab in neutral to slight supination for 3-4 weeks
• Radiographic follow-up at weekly intervals for the first 3 weeks to detect late displacement
• Begin gentle active forearm rotation exercises once the cast is removed
• Formal physiotherapy if rotation is restricted at cast removal

Evidence for Non-Operative Treatment

• Children under 10 years with less than 30 degrees of residual angulation have excellent outcomes with non-operative treatment — remodeling corrects the majority of residual tilt over 12-18 months
• Children over 10-12 years have less remodeling potential, and residual angulation greater than 20-30 degrees may persist into adulthood
• Non-operative management of minimally displaced fractures yields good or excellent functional outcomes in approximately 85-95% of cases in the literature

Evidence for Operative Intervention

Closed Reduction — Patterson Manoeuvre

• Original description by Patterson (1934): a manipulative closed reduction technique using direct thumb pressure on the displaced radial head combined with valgus stress and forearm rotation
• Suitable for Judet Type II and some Type III fractures with moderate displacement
• Success rates reported at approximately 50-70% for Judet II fractures, lower for Judet III-IV
• No fixation is placed — reduction is maintained by cast immobilisation in pronation (which tensions the interosseous membrane and supports the radial head)
• Limit to two attempts; each attempt further risks the metaphyseal blood supply

Percutaneous Push (Direct Reduction)

• Under image intensifier guidance, a K-wire or blunt trocar is introduced percutaneously onto the displaced radial head and used to push it into position
• Avoids open dissection but still requires violation of the joint capsule
• Combined with the Patterson positioning manoeuvre (forearm supination, valgus stress)
• Useful for Judet II-III fractures with significant translation but accessible head fragment

Métaizeau Intramedullary Nailing

• Described by Métaizeau et al. (1993): retrograde insertion of a pre-bent elastic (TEN) nail up the radial medullary canal from the distal metaphysis
• The nail tip is used as a joystick at the fracture site to lever the displaced head into reduction
• Once reduced, the nail is advanced across the fracture into the epiphysis to provide stable internal fixation
• This is the preferred technique for Judet III and IV fractures in most paediatric orthopaedic centres
• Outcomes reported as good or excellent in 70-90% of series, with AVN rates substantially lower than open reduction

Key Evidence

Proximal Radius in the Growing Child

The Open Physis — Why the Neck Fractures, Not the Head

The proximal radial physis is the weakest point of the proximal radius in children. The radial head (epiphysis) is united to the metaphysis through this growth plate. When a fracture occurs through the radial neck, the epiphysis and physis remain attached to the head fragment and displace as a unit.

The metaphysis (radial neck) fractures because it is relatively thin and the bone is less dense than the mature adult radial neck. The epiphysis (the ossific nucleus of the radial head) is small in younger children and may not even be visible on radiograph before age 5-6.

Clinical implication: The fracture line passes through the metaphysis of the radial neck, NOT through the physis. The physis remains intact on the displaced fragment. However, the vascular pedicles that supply the epiphysis travel through the metaphysis and across the physis — disruption at the fracture site compromises this supply.

Metaphyseal Anatomy of the Radial Neck

• The radial neck in a child is approximately 1-2 cm in length
• The medullary canal is wide enough to accept a 1.5-2.0 mm elastic nail in most children
• The cortex is thin — excessive levering with instruments can cause iatrogenic fracture propagation
• The anterolateral cortex is the most common starting point for the fracture line

Blood Supply of the Developing Radial Head

Metaphyseal Vessels (Dominant in Children)

• Branches of the radial artery supply the metaphyseal region of the radial neck
• These vessels ascend along the radial neck and penetrate the physis to reach the epiphysis
• This is the PRIMARY blood supply to the radial head in children — approximately 80-90% of the total supply

Intraosseous Vessels

• Vessels within the medullary canal of the radial neck supply the metaphyseal cortex
• Disruption of these vessels at the fracture site contributes to AVN risk

Capsular and Ligamentous Vessels

• Small capsular vessels enter near the articular margin of the radial head
• These are a MINOR supply in children (the major intra-articular supply develops after physeal closure)
• Opening the joint capsule unnecessarily further compromises the blood supply

Surgical Approaches to the Proximal Radius

Kocher Approach (Lateral — Primary for Open Reduction)

• Interval: Between anconeus (posterior) and extensor carpi ulnaris (anterior)
• Deep dissection: Supinator muscle is encountered; the posterior interosseous nerve (PIN) runs within the supinator, entering at its proximal border and exiting distally
• PIN protection: Identify the PIN at the proximal edge of supinator before splitting or retracting the muscle
• Exposure: Provides access to the radial neck and the lateral aspect of the proximal radius
• Limitation: Does not provide extensive access to the medial radial neck; best for lateral displacement patterns
• Risk: PIN injury if the supinator is split without identifying the nerve; synostosis risk if the interosseous membrane is violated

Kaplan Approach (Anterolateral — Alternative)

• Interval: Between brachioradialis and extensor carpi radialis longus
• Deep dissection: The radial nerve and its PIN branch are encountered — identify and protect
• Exposure: Provides access to the anterolateral radial neck and the radial tuberosity
• Advantage: May be preferable for anterolateral fracture patterns
• Risk: Superficial radial nerve (sensory branch) at risk in the proximal interval

Structures at Risk During Surgery

Positioning and Preparation

Patient position: Supine with the arm draped free on a radiolucent hand table. Use a tourniquet on the upper arm (inflated to 200-250 mmHg depending on the child's size). Position the image intensifier from the lateral side to obtain true AP and lateral views of the elbow.

Anaesthesia: General anaesthesia for all children. A well-padded tourniquet is applied to the upper arm. Pre-operative antibiotics (single dose of cefazolin) at induction.

Image intensifier: Obtain and save AP and lateral views of the elbow and proximal forearm before prepping and draping. These are the baseline for measuring the Judet angle and planning reduction.

Consent: Specifically counsel regarding: risk of AVN of the radial head (3-10% with Métaizeau, up to 30-50% with open reduction), loss of forearm rotation (10-30%), premature physeal closure causing progressive valgus (5-15%), radioulnar synostosis (1-5%), need for further surgery or implant removal, and the possibility of accepting an imperfect reduction in favour of preserving the blood supply.

Closed Reduction — Patterson Manoeuvre

Indications

• Judet Type II fractures (30-60 degrees angulation)
• Some Judet Type III fractures with moderate translation and an accessible head fragment
• First-line reduction attempt before proceeding to Métaizeau or open reduction

Step 1: Positioning and Leverage

Supinate the forearm. The surgeon places the thumb of one hand directly over the displaced radial head, palpable posterolaterally at the lateral elbow. The other hand grasps the distal forearm.

Step 2: Reduction Manoeuvre

Apply direct pressure on the radial head from the posterolateral aspect, pushing it medially and anteriorly towards the radial shaft. Simultaneously apply a gentle valgus stress to the elbow and rotate the forearm from supination to pronation. The combination of direct pressure, valgus opening, and forearm rotation levers the head back into alignment.

Step 3: Verify Reduction

Check the image intensifier for improvement in the Judet angle. If reduction to less than 30 degrees is achieved in a child under 10, this may be accepted. If residual angulation remains greater than 30 degrees, proceed to percutaneous push or Métaizeau technique.

Percutaneous Push (Direct Reduction)

Indications

• Judet II-III fractures where the Patterson manoeuvre has failed but the radial head fragment is accessible percutaneously
• Fractures with significant translation (the head is displaced laterally and can be engaged with a K-wire)

Technique

1. Confirm fracture configuration on image intensifier — identify the displaced radial head fragment
2. Make a small stab incision over the lateral elbow at the level of the radial head
3. Introduce a 2.0 mm K-wire or blunt trocar percutaneously under image guidance onto the radial head fragment
4. Use the wire as a joystick to push the head medially and anteriorly while an assistant applies valgus stress and forearm rotation
5. Confirm reduction on AP and lateral image intensifier views
6. Withdraw the K-wire. If reduction is stable (less than 30 degrees residual tilt), proceed to cast immobilisation
7. If reduction is achieved but unstable, proceed to Métaizeau intramedullary nailing to stabilise

Métaizeau Intramedullary Nailing — Step-by-Step

Step 1: Planning Nail Insertion Site

Identify the distal radial metaphysis on image intensifier — approximately 2-3 cm proximal to the distal radial physis. Mark the skin over the radial styloid process and plan a small longitudinal or oblique incision on the lateral aspect of the distal radial metaphysis.

Step 2: Exposure and Cortical Entry

Make a 1-2 cm incision over the lateral distal radial metaphysis. Identify the radial cortex between the extensor tendons (protect the superficial radial nerve dorsally and the radial artery volarly). Use a small awl or drill to create a cortical entry point in the lateral cortex, angled slightly proximal to match the medullary canal.

Step 3: Nail Selection and Insertion

Select a pre-bent elastic (Titanium Elastic Nail, TEN) of appropriate diameter — typically 1.5-2.0 mm depending on the child's size (the nail should fill approximately two-thirds of the medullary canal diameter). The nail has a pre-formed curve at its tip — this curve is essential for the joystick manoeuvre.

Insert the nail retrograde up the medullary canal towards the proximal radius under image intensifier guidance. Advance the nail until its tip reaches the fracture site at the radial neck.

Step 4: Joystick Reduction

Once the nail tip is at the fracture site, use it as a joystick: rotate the nail to lever the tilted radial head fragment back into alignment with the neck. This is done under continuous image intensifier guidance. The pre-bent tip of the nail engages the fracture surface of the displaced fragment and, with rotation, pushes it into position.

Combined with the Patterson positioning (forearm supination, valgus stress), the joystick action of the nail tip reduces the fracture.

Step 5: Advance Nail Across Fracture for Stabilisation

Once the radial head is reduced (Judet angle less than 30 degrees ideally, or the best achievable reduction), advance the nail across the fracture site and into the proximal fragment (epiphysis) to stabilise the reduction. The nail should engage the proximal fragment but NOT breach the articular surface of the radial head.

Confirm on AP and lateral views that the nail is within the medullary canal of both fragments, the reduction is acceptable, and the nail tip is not protruding into the radiocapitellar joint.

Step 6: Nail Preparation and Closure

Cut the nail beneath the skin at the distal insertion site, leaving sufficient length for later removal. Bend the distal end of the nail to prevent migration. Close the distal incision with absorbable sutures.

Step 7: Immobilisation

Apply an above-elbow cast or backslab in neutral to slight supination for 3-4 weeks. The nail provides internal fixation, but the cast protects against rotational and angular forces during early healing.

Open Reduction — Technique of Last Resort

Indications

• Judet III-IV fractures irreducible by closed manipulation and Métaizeau technique
• Fractures with interposed soft tissue (annular ligament, capsule, or periosteum) blocking closed reduction after two attempts
• Fractures associated with other injuries requiring open treatment (Monteggia equivalent, olecranon fracture)

Approach: Kocher Lateral Approach

1. Incision: Curved lateral incision centred over the lateral epicondyle, extending approximately 5-8 cm distally along the subcutaneous border of the ulna
2. Identify the interval between anconeus (posterior) and extensor carpi ulnaris (anterior)
3. Deepen the dissection to the supinator muscle
4. Identify the posterior interosseous nerve at the proximal border of the supinator — this is the critical step. The PIN runs within the supinator from proximal-lateral to distal-medial
5. Retract the supinator to expose the radial neck fracture site

Reduction and Fixation at Open Surgery

1. Gently elevate the radial head fragment using a small elevator or bone hook — minimise soft tissue attachment disruption
2. Clear any interposed tissue (annular ligament, capsule, periosteum) from the fracture site
3. Reduce the radial head fragment to the neck under direct vision
4. Stabilise with K-wires (smooth 1.5-2.0 mm) or a small mini-fragment plate if the child is large enough and the fracture pattern allows
5. Avoid drilling bicortically in a direction that breaches the interosseous membrane and enters the ulna — this creates a synostosis risk
6. Check the radiocapitellar joint to confirm the reduction is anatomic and no hardware protrudes intra-articularly
7. Close the supurator interval, capsule (if opened), and skin in layers

Post-operative Protocol

Phase 1: Immobilisation (Weeks 0-3-4)

• Cast: Above-elbow cast or backslab in neutral to slight supination
• Métaizeau nail: Provides internal fixation; the cast protects against angular and rotational loads
• Elevation: Reduce swelling for first 48 hours
• Analgesia: Paracetamol and ibuprofen (NSAIDs may also reduce heterotopic bone formation risk)
• Imaging: Check reduction at 1 week; repeat at 3-4 weeks before cast removal to confirm maintenance

Phase 2: Mobilisation (After Cast Removal)

• Active forearm rotation exercises: Begin immediately after cast removal — this is the critical rehabilitation phase
• Goal: Recover full pronation and supination arcs
• Physiotherapy referral: For all patients with restricted rotation at cast removal
• Métaizeau nail: Typically removed at 6-8 weeks post-operatively once the fracture has consolidated clinically and radiographically

Phase 3: Nail Removal and Return to Activity

• Nail removal: At 6-8 weeks under short general anaesthetic; small incision over the distal insertion site
• Return to sport: Non-contact sport at 6-8 weeks; contact sport at 3 months
• Follow-up imaging: At 6 weeks (nail removal), 3 months, 6 months, and 12 months — specifically looking for early AVN and physeal closure

Long-Term Surveillance

• Serial radiographs at 6 months and 12 months are essential to detect late AVN and premature physeal closure
• Measure the carrying angle at each visit and compare with the contralateral elbow
• Document forearm rotation arcs (pronation and supination in degrees) at every visit
• AVN may not appear radiographically until 6-12 months — a normal 6-week film does not exclude it

Special Case: Monteggia Equivalent

Recognising the Association

• A paediatric radial neck fracture may be the equivalent of a Monteggia lesion if there is associated plastic deformation of the ulna
• The ulna does not fracture (as in a classic Monteggia) but bows — this is a plastic deformation pattern unique to children
• The radial head displaces because the ulna has lost its normal alignment, analogous to the adult Monteggia mechanism

Management Implications

• If an associated ulna plastic deformation is identified, the ulna must be corrected to restore the radiocapitellar joint
• Perform a gentle manual corrective osteotomy of the ulna (hyperflexion of the elbow with direct pressure on the apex of the ulna bow) to restore ulnar alignment
• Once the ulna is corrected, the radial head may reduce spontaneously or become amenable to closed manipulation
• Failure to recognise and correct the ulna bow results in persistent radial head subluxation

Special Case: Radial Neck Fracture in the Adolescent (Near-Skeletal Maturity)

Why the Adolescent Is Different

• The proximal radial physis is approaching closure — remodeling potential is limited
• Residual angulation is less likely to correct over time
• The blood supply pattern is transitioning from metaphyseal-dominant to the adult pattern (dual supply from metaphyseal and intraosseous vessels)
• The fracture mechanism and pattern may resemble adult radial head fractures

Management Modifications

• Lower threshold for anatomic reduction — residual angulation greater than 20-30 degrees is less well tolerated
• Métaizeau technique remains preferred if the medullary canal accepts a nail
• Open reduction may be more acceptable in an older adolescent because the AVN risk is lower than in a younger child (more mature blood supply pattern)
• Implant options expand: mini-fragment plates become feasible in the larger adolescent radial neck

Special Case: Bilateral Radial Neck Fractures

Mechanism and Assessment

• Bilateral radial neck fractures in children suggest high-energy mechanism — assess for associated injuries (spine, chest, contralateral limb)
• Falls from height, road traffic accidents, and significant sports injuries are typical mechanisms
• Each side must be classified and managed independently

Practical Management

• Both sides can be managed with Métaizeau intramedullary nailing in a single anaesthetic session
• Bilateral above-elbow casts are applied; this significantly limits the child's independence
• Consider staged procedures if the anaesthetic time is prolonged or the child is very young
• Intensive physiotherapy is needed after bilateral cast removal to prevent severe stiffness