Authors of section

Authors

Andrew Howard, Theddy Slongo, Peter Schmittenbecher

Executive Editor

James Hunter

General Editor

Fergal Monsell

Open all credits

Open reduction; K-wire fixation

1. General considerations

K-wire fixation provides less stability than ESIN fixation. It needs additional cast or splint immobilization to prevent elbow movement during healing causing elbow stiffness. Other potential disadvantages include infection and cross-union.

Open reduction; K-wire fixation

This treatment may be used for reduction and fixation of a radial head that is severely displaced or if an image intensifier is not available.

Grossly displaced radial head

2. Instruments and implants

The following equipment is needed:

  • K-wires of appropriate sizes
  • Drill or a T-handle for manual insertion
  • Wire cutting instruments
  • Standard orthopedic instrument set
Open reduction; K-wire fixation - Instruments and implants

3. Patient preparation

This procedure is normally performed with the patient in a supine position.

Patient preparation

4. Approaches

A direct lateral or a posterolateral approach may be used. This is associated with a high risk of disruption of the remaining blood supply.

Open reduction; K-wire fixation - Approaches

5. Reduction

Protect the remaining periosteum throughout the reduction maneuvers.

Pearl: minimizing additional vascular damage to the radial head

To minimize the risk of additional vascular damage to the radial head the following procedure is recommended:

1. Attempt initial reduction of the fracture through the closed capsule.

2. If unsuccessful, perform a dorsolateral arthrotomy with irrigation of the joint. The displaced radial head can usually be seen , irrespective of the direction of displacement.

Minimizing additional vascular damage to the radial head

3. Digitally reduce the head fragment .

Open reduction; K-wire fixation - Manual reduction

4. If the head is entrapped/displaced in an unusual direction use a dental hook or an identical shaped K-wire push/pull the radial head to an appropriate position .

Open reduction; K-wire fixation - Reduction with a hook

6. Fixation

Preliminary fixation

After anatomical reduction the head fragment, placed between the metaphysis of the radius and the capitellum, is usually stable. Preliminary fixation is therefore not necessary.

General K-wire principles

Use K-wires with a sharp tip.

Powered insertion of K-wires generates heat in the tissues. Insert wires with a slow-running drill or by hand.

If multiple attempts are made to insert any one K-wire the bone may be weakened or the physis may be damaged. In general, only two attempts of insertion of any K-wire are advisable.

See the additional material for further information on K-wire principles.

Insertion of K-wires

The K-wires must provide adequate spread at the fracture site on any view.

If the K-wire spread is inadequate, the fixation is likely to be rotationally unstable.

Pitfall: The K-wires should engage the far cortex but not protrude into the soft tissues.

Open reduction; K-wire fixation - K-wire insertion

Confirm the position of the K-wires on both AP and lateral views.

If the position is inadequate, adjust the K-wires.

Open reduction; K-wire fixation - Confirmation of K-wire position

Trimming of K-wires

Whether the K-wires are left outside the skin or cut and buried beneath the skin depends on the surgeon’s preference.

K-wires may be left protruding, but there is a risk of pin-track infection. The advantage is that the K-wires can be removed without anesthesia.

Open reduction; K-wire fixation - Trimming of K-wires

Wound closure

Close the wound in layers with resorbable sutures.

Open reduction; K-wire fixation - Wound closure

Final radiological documentation

Take standard x-rays in lateral and AP view.

7. Additional immobilization

K-wire fixation alone confers minimal stability. Additional immobilization is required to reduce the risk of secondary displacement.

Immobilize the arm in 90° flexion of the elbow with a cast or a splint to prevent elbow movement.

Open reduction; K-wire fixation - Additional immobilization

8. Aftercare following K-wire fixation and immobilization

Duration of immobilization

Radial head and neck fractures usually require 3-4 weeks of cast immobilization for adequate callus formation.

cast immobilization

Analgesia

Ibuprofen and paracetamol should be administered regularly during the first 24-48 hours after surgery, with opiate analgesia for breakthrough pain.

Opiates should not be necessary after 48 hours and regular ibuprofen and paracetamol should be sufficient until 4-5 after injury or surgery.

The child should be examined if the level of pain is increasing or prolonged analgesia is needed.

Neurovascular examination

The child should be examined after casting/splinting, to ensure finger range of motion is comfortable and adequate.

Neurological and vascular examination should also be performed.

Compartment syndrome should be considered in the presence of increasing pain, especially pain on passive stretching of muscles, decreasing range of active finger motion or deteriorating neurovascular signs, which is a late phenomenon.

See also the additional material on complications and postoperative infections.

cast immobilization

Compartment syndrome

Compartment syndrome is a possible early postoperative complication that may be difficult to diagnose in younger children.

The presence of full passive or active finger extension, without discomfort, excludes muscle compartment ischemia.

If there are signs of a compartment syndrome in a child in a cast or splint:

  1. Remove or split constrictive dressings or casts.
  2. Elevate the limb.
  3. Encourage active finger movement.
  4. Reexamine the child after 30 min.

If a definitive diagnosis of compartment syndrome is made, then a fasciotomy should be performed without delay.

cast immobilization

Discharge care

Discharge from hospital follows local practice and is usually possible after 1-3 days.

The parent/carer should be taught how to assess the limb.

They should also be advised to return if there is increased pain or decreased range of finger movement.

It is important to provide parents with the following additional information:

  • The warning signs of compartment syndrome, circulatory problems and neurological deterioration
  • Hospital telephone number
  • Information brochure

For the first few days, the elbow and forearm can be elevated on a pillow, until swelling decreases and comfort returns.

Removal of cast or splint

Remove the cast after 3-4 weeks after the injury before taking the control x-ray.

Clinical assessment and x-rays without cast are used to judge adequate healing.

Follow-up

AP and lateral x-rays may be taken at 3-4 weeks following injury to assess position and healing.

See also the additional material on complications.

K-wire removal

Protruding K-wires can be removed immediately after follow-up x-ray.

Buried K-wires can be removed as a day case under anesthesia.

A small portion of the old incision is opened directly over the palpable tips of the bent K-wires. Wires are extracted with pliers or a heavy needle holder.

Recovery of motion

As symptoms recover, the child should be encouraged to remove the sling and begin active movements of the elbow and forearm rotation. See also the additional material on elbow stiffness.

The majority of motion is recovered rapidly and within two months of cast or splint removal.

Physiotherapy is normally not indicated.

The older child may take a little longer.

Once the child is comfortable, with a nearly complete range of motion, he/she may incrementally resume noncontact sports.

Resumption of unrestricted physical activity is a matter for judgment by the treating surgeon.