General Editor: Chris Colton

Authors: Fergal Monsell, Dalia Sepulveda

Pediatric distal forearm 23-E/2.1

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Glossary

1 Introduction top

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These fractures are usually posteriorly angulated (apex anterior) and can generally be reduced closed, ideally under general anesthesia. Impediments to reduction are interposed periosteum and pronator quadratus.

Many of these fractures are stable after reduction and do not require wire fixation. K-wire stabilization may be necessary in some cases.

Anteriorly angulated (apex posterior) fractures are less common and are also generally reduced closed. Impediments to reduction are the extensor tendons.

2 Reduction top

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Indirect reduction of partially displaced fractures

The reduction maneuver for posteriorly angulated fractures, together with some posterior translation (common) is by traction and direct pressure over the epiphysis, followed by palmar flexion.

Ideally, the reduction is verified with image intensification and any residual malalignment is corrected with direct pressure.


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The reduction maneuver for anteriorly angulated fractures, together with some anterior translation (uncommon) is by traction and direct pressure over the epiphysis, followed by dorsiflexion.

Ideally, the reduction is verified with image intensification and any residual malalignment is corrected with direct pressure.


Repeated reduction maneuvers, or delayed reduction (after 5-7 days) can damage the growth plate and result in premature growth arrest.

In such instances, the options are to accept the deformity in anticipation of modelling with subsequent growth.

In rare instances with fresh injuries, the gentle use of a “joystick” K-wire inserted into the distal fragment can be performed.


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Indirect reduction of completely displaced fractures

For completely posteriorly displaced fractures, direct pressure is applied to the epiphysis with the wrist in hyperdorsiflexion.


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The fracture is then reduced by palmarflexion, while continuously applying direct pressure to the epiphysis.


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Once the radius is reduced, the ulna will also reduce.

Ideally, this should be confirmed using image intensification.

In cases of persistent malreduction of the ulna, direct pressure on either the posterior…


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…or anterior surface of the epiphysis should produce a satisfactory reduction.


The reduction is often straightforward and may not require K-wire fixation, if it is stable. Relaxing the manual reduction pressure, will determine whether it is stable, as an unstable reduction will redisplace.


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Direct reduction using K-wire

For irreducible fractures, a percutaneous K-wire can be inserted (through a stab incision) into the distal fragment and used as a joystick lever to facilitate reduction.

3 K-wire fixation top

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General considerations

For fractures that are unstable after reduction, a single K-wire is usually sufficient to stabilize the fracture.

Occasionally a second wire is used to stabilize the ulna.


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In cases of a more lateral metaphyseal wedge, the K-wire is inserted more in the coronal plane than in the sagittal plane.


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Skin incision

A small skin incision is required for the K-wire insertion.

Care should be taken to avoid the sensory branch of the radial nerve.

The incision is deepened to the bone using a blunt artery forceps and a protective sleeve is inserted.


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K-wire insertion

Via the protective sleeve, a single smooth 1.6 mm K-wire is inserted through the dorsal metaphyseal fragment engaging the anterior cortex of the radial diaphysis.

The wire should be inserted with an oscillating drill and cooled with saline to prevent thermal injury. Alternatively, the wire can be inserted manually using a T-handle.

Care should be taken to avoid the dorsal sensory branch of the radial nerve.


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Ideally, wires are inserted using image intensification control, in order to check the trajectory of the wire and to ensure engagement of the far diaphyseal cortex without penetration of soft tissues.


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Occasionally a second wire is used to stabilize the ulna.

Care should be taken to avoid injury to the dorsal sensory branch of the ulnar nerve.

For more technical details on K-wire fixation of the distal ulna, please refer to the isolated distal ulnar fracture (23u-E2.1).


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Each K-wire is left protruding through the skin, bent and cut. The skin is protected with sterile padding prior to the application of a cast.

The illustration demonstrates the use of a small section of plastic tubing over the cut end of the protruding wire. This adds further protection for the skin.

Note: Excessive pressure between dressing and skin should be avoided to prevent skin necrosis.

4 Short arm cast top

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General considerations

The purpose of the cast is protective and for pain relief, as stability is provided by the K-wire fixation.

The short arm cast is applied according to standard procedure:

Note: In young, small, or noncompliant patients, it is safer to apply a long arm cast.


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Splitting of the cast

If a complete cast is applied in the acute phase after injury, it should be split over the full length of the cast. The split of the cast must be full thickness and expose the underlying skin.

5 Long arm cast top

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In the event that a long arm cast is necessary (see above) it is applied and split according to standard procedure:

v1.0 2016-12-01