Radial Neck Fracture Repair In A Child

Anatomy and Physiology

Long bones can be divided into three sections:

1. Epiphysis: The end of a bone, covered in articular cartilage if it is part of a joint.
2. Diaphysis: The midsection or shaft of the bone.
3. Metaphysis: The section between the epiphysis and diaphysis; this section contains the growth plate (physis) during childhood.

Ossification centers are parts of the bone involved in osteogenesis and can be divided into primary and secondary. The primary ossification center is where the bone first forms, for example, the diaphysis in long bones. Secondary ossification centers are usually found in the epiphysis, and there may be multiple centers present. There are six ossification centers around the elbow joint, which may be remembered using the mnemonic ‘CRITOE.’ The location and years of age at which these ossification centers appear around the elbow are:

1. Capitellum (1 year)
2. Radial head (3 years)
3. Internal or medial epicondyle (5 years)
4. Trochlea (7 years)
5. Olecranon (9 years)
6. External or lateral epicondyle (11 years)

The radial head fuses with the shaft between 16 to 18 years of age. Fractures of the radial neck usually involve the proximal radial physis; hence can be usually classified as Salter-Harris type-2 injury.

Indications

Operative radial neck fracture repair is usually indicated when the fracture angulation is greater than 30 degrees following attempts at closed reduction, translation of greater than 3 mm, and reduced range of supination and pronation of under 45 degrees. For cases in which angulation is close to thirty degrees, closed reduction with immobilization in a long-arm cast is acceptable. Closed percutaneous reduction using a K-wire or the Metaizeau technique using an elastic retrograde intramedullary (IM) nail can be trialed if closed reduction maneuvers fail and an angulation deformity of greater than 30 degrees persists.[1][2][3] If an angulation deformity of greater than 45 degrees persists despite attempts at a closed percutaneous reduction, then open reduction should be undertaken with caution.[4][5]

Contraindications

Operative repair of radial neck fractures is contraindicated if the fracture is minimally angulated (less than 30 degrees) and translated (less than 3 mm translation). Fractures that have more than 30 degrees of angulation may be managed with a closed reduction if an adequate reduction is achieved.

Equipment

• Image intensifier (II)
• Skin preparation with an antiseptic solution
• 5-3.0 mm elastic nails
• Nail inserter
• Small hammer
• Nail cutter
• 30 cm long, 1.6 to 2.5 mm K-wires
• Drill or T-handle
• Wirecutter
• Skin scalpel
• Inside scalpel
• Forceps
• Small retractors
• Small scissors or a surgical clip
• Dental hook
• Diathermy
• Sutures
• Dressing

Personnel

This procedure should be carried out by surgeons with appropriate training and experience; this may be a registrar (resident) or consultant (attending). The theater team will include an anesthetic team, operating department practitioners, a scrub nurse, and a radiographer.

Preparation

In preparation for this procedure, a theater team brief should take place where team members are introduced, roles established, cases briefly discussed, including the list order, equipment required, and patient position. Prior to the start of the procedure, the surgical team should complete the World Health Organisation (WHO) surgical safety checklist. The patient is positioned supine with the affected arm on an arm board. The patient should then be prepped and draped to above the elbow.

Technique or Treatment

Closed Reduction- K-wire Joystick Technique

• Insert a 1.6 or 2.0 mm K-wire percutaneously and push the radial head to an appropriate position. Use II to assist K-wire insertion and confirm fracture reduction.

Closed Reduction and Internal Fixation - Elastic Stable Intramedullary Nailing (ESIN)-(Métaizeau technique)

• There are 2 possible entry points that can be used:
  • Distal lateral entry point: This is the lateral side of the radius and 1.5 cm proximal to the physis. The incision should be made at this point and extended 2 cm distally.
  • Dorsal entry point: This is 1.5 cm proximal to the growth plate in the metaphysis, in line with the Lister tubercle, which lies in the physis in children. A transverse skin incision should be made.

• If II is unavailable, either entry points can be utilized by making an incision 3-4 cm proximal to the wrist joint laterally or dorsally.
• Use a surgical clip or scissors and small retractors to dissect down to bone under direct vision. Be aware of the superficial radial nerve, and the cephalic vein will be in this region and should be retracted radially.
• Place the drill or awl directly onto the bone and ensuring the drill or awl is perpendicular to the bone, perforate the proximal cortex under direct vision. Do not use a hammer with the awl as there is a risk of perforation of the distal cortex.
• Once in the medullary canal, lower the drill or awl to 45 degrees to the medullary axis and advance.
• The nail has a blunt tip making it difficult to enter the hard epiphysis, and it can sometimes displace the radial head. So, next, contour the nail tip by cutting the inner end.
• Attach the nail into the inserter.
• With the tip perpendicular to the medullary axis, insert the nail till the distal cortex is felt. Rotate the nail 180 degrees so that the curved side of the nail tip can be used to glide the nail and advance up the canal to the fracture site using an oscillating maneuver.
• Using II, rotate the arm to achieve a maximal displacement of the fracture. Then point the nail tip to the radial head fragment.
• If the head is too displaced for the nail tip to enter it, reduction techniques should be used, such as traction or by applying pressure over the radial head under varus stress.
• If unsuccessful, the nail should be removed, recontoured to give a more distinct bend, and then reinserted.
• If the nail still cannot advance into the head, the blunt end of a K-wire can be inserted percutaneously through a stab incision, and this can be used to push the radial head in order to reduce the fracture.
• The fragment may be too small, and, in such cases, the sharp end of the K-wire may need to be used as a ‘joystick.’ Care must be taken to preserve the blood supply via the metaphyseal branches to the radial head.
• In cases where II is unavailable, or the displaced radial head cannot be reduced, you should proceed with open reduction.

Open Reduction

• A lateral skin incision can be used by placing the elbow at 90 degrees and palpating the lateral condyle. Make a 5-6 cm gently curved skin incision over the lateral condyle.
• Alternatively, a posterolateral incision may be used by making an incision behind the supracondylar ridge to the lateral border of the ulna.
• To avoid potential vascular damage, attempt reduction through a closed capsule and, if unsuccessful, then perform a dorsolateral arthrotomy.
• Use a K-wire or dental hook to manipulate the radial head.
• Advance the nail into the radial head.
• Disimpact the head with light taps using the hammer at the nail end.
• Achieve anatomical reduction by rotating the nail either anticlockwise or clockwise.
  • If a lateral nail entry point was used:
    • Carefully withdraw the nail by 1 cm in order to cut the nail outside the skin. 
    • Cut the nail near the bone using a nail cutter.
    • Reinsert the nail to its original position using an impactor
    • Check that the nail tip is not going to cause irritation of the superficial radial nerve.
  • If a dorsal nail entry point was used:
    • The nail should be left long or covered with an end cap to prevent tendon rupture (extensor pollicis longus at risk).
  • Close the wound.

Open Reduction Techniques- K-wire Fixation 

• Follow the above steps in the open reduction section to achieve anatomical reduction at the fracture site.
• Stab incisions should be made over the entry point. An oscillating drill should be used to avoid thermal damage; if unavailable, a standard drill should be used slowly and/or cooled with irrigation fluid. A drill sleeve can be used to protect soft tissues and stabilize the K-wire.
• K-wires should be inserted from the free fragment into the main fragment.
• Ensure that the K-wire entry points are such that the K-wires are well apart at the fracture site. This will ensure rotational stability.
• Confirm the position of the K-wires on both AP and lateral views using II and adjust as appropriate.
• Trim the K-wires and bury them or allow them to protrude through the skin for removal under local anesthesia at a later stage. If left protruding, there is a risk of pin site infection.
• Close the wound.
• K-wire fixation provides minimal stability, and additional immobilization is needed to avoid secondary fracture displacement. Immobilize the arm using a cast or splint with the elbow in 90 degrees of flexion.
• Protruding K-wires should be removed after follow-up X-rays at 3 to 4 weeks post-operatively.
• Buried K-wires can be removed under anesthetic as a day case.

Complications

Avascular necrosis (AVN) is one of the most significant complications from radial neck fractures. AVN can occur in 10% to 20% of radial neck fractures. Since the radial head relies on blood supply from the periosteum, the risk of AVN is even higher, up to 70%, in cases requiring open reduction due to damage to the periosteum. Elbow stiffness and decreased range of motion can be difficult to treat; therefore, prevention with an early active-assisted range of motion is crucial. In children, a safe and easy way to achieve this is by teaching children how to use their other arm to carry out movements on the affected side. Another cause of reduced function and range of movement can be due to malunion and non-union, highlighting the need for accurate reduction. Management of both malunion and non-union should be considered on a case by case basis depending on the patient’s signs, symptoms, and function.[6][7]

Radioulnar synostosis is the fusion of the radius to the ulna, which may be due to reflected periosteum. The condition can hinder pronation, supination, and result in shortening of the arm. It is more common in cases that have delayed treatment or open reduction cases in which extensive dissection has been undertaken. Osteotomy procedures can be used to treat synostosis with the aim of improving function. Finally, compartment syndrome is a possible postoperative complication that presents early and can be challenging to diagnose in children. Compartment syndrome should be suspected in children with increasing pain or pain that is not responsive to opioids. If a definitive diagnosis of compartment syndrome is made, then a fasciotomy will need to be performed without delay.

Clinical Significance

Attempts should be made to manage radial neck fractures with closed reduction and manipulative closed reduction.[8][9] If unsuccessful, gentle open reduction techniques can be used, but care must be taken to avoid damage to the periosteal hinge and preserve the blood supply.[10] Open reduction is associated with greater rates of loss of function, AVN, and synostosis. Additionally, not all fractures will require reduction, and conservative management is a valid treatment option for fractures that are minimally displaced.

Enhancing Healthcare Team Outcomes

Management of radial neck fractures in children should be undertaken by an interprofessional team. Following surgery, support from allied healthcare professionals, in particular physiotherapists and occupational therapists, will further enhance the patient experience. These professionals should be routinely available to deliver a therapy plan that children will be able to follow at home. The child should be encouraged to start early range of movement to avoid stiffness. Patients are usually followed up in a fracture clinic, which is conducted with support from plaster technicians and radiographs. This improves clinic flow, ensures patient safety, and enables high-quality care. Open communication with parents and thorough reviews in the fracture clinic will ensure holistic care is provided to these pediatric patients, and potential complications are flagged early.