Authors of section

Authors

Fergal Monsell, Dalia Sepulveda

General Editor

Chris Colton

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Closed reduction; Long arm cast

1. Introduction

These fractures are often caused by a direct blow. The direction of displacement depends on the direction of the blow.

In younger children bear in mind the possibility of nonaccidental injury.

closed reduction long arm cast

2. Patient preparation

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

closed reduction short or long arm cast

3. Anatomy of the distal forearm

A thorough knowledge of the anatomy of the wrist is essential.

The additional material gives a short introduction.

closed reduction short or long arm cast

4. Reduction

Direct reduction using K-wire

In the presence of an intact radius, and complete displacement, it is not possible to achieve closed reduction. Direct reduction using a percutaneous K-wire (inserted through a stab incision) is required.

closed reduction long arm cast

5. Long arm cast

General conciderations

Once the fracture displacement has been reduced, the arm is splinted in a long arm cast.

The purpose of the cast is to maintain the reduction by preventing forearm rotation.

The position of the forearm depends on the direction of the original displacement, with the forearm pronated for a anteriorly displaced fracture, and supinated for a posteriorly displaced fracture.

The long arm cast is applied according to standard procedure:

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Splitting of the cast

If a complete cast is applied in the acute phase after injury, it is safer to split the cast down to skin over its full length.

closed reduction long arm cast

6. Aftercare

Tight cast

Further swelling in a restricting cast can cause pain, venous congestion in the fingers and occasionally a compartment syndrome.

For this reason any complete cast applied in acute phase should be split down to skin.


closed reduction short or long arm cast

Parents/carers should be instructed how to detect circulatory problems by pressing and releasing the fingertips and watching if the blood flow/color returns to normal (capillary refill), compared to the opposite hand.


closed reduction short or long arm cast

Compartment syndrome

Compartment syndrome is an unusual but serious complication after the application of a complete cast and can be difficult to diagnose, especially in younger children. Neurological signs appear late and the main sign is excessive pain on passive extension of the fingers.

It is important to make sure that the parents/carers are aware of the risk of compartment syndrome.


closed reduction short or long arm cast

The parents/carers and patient should be informed to take note of increased pain and/or unresponsiveness to normal painkillers.

They should know that this may indicate serious complications. It is important for them to detect these signs as early as possible and report them urgently to the surgeon/nurse by telephone, or to attend the Emergency Room (ER) without delay.


closed reduction short or long arm cast

Nerve compression is an occasional complication and the signs include:

  • Sensory deficits (numbness)
  • Weakness of active finger movement
  • Paresthesia (tingling)

Infections

See also the additional material on postoperative infections.

Cast care

If a normal plaster of Paris cast is used, it is important to keep the cast clean and dry in order to maintain the reduction.

When the swelling has reduced, the cast can become loose. The loss of support can result in loss of reduction.

In this circumstance, the parents/carers are advised to return to the healthcare provider.

Follow-up x-rays

Depending on the fracture pattern, the age of the child and the method of treatment, the patient has to return for follow-up x-rays to monitor the fracture position.

X-rays taken for fracture position can be taken with cast in place. Any x-rays to assess the state of bone healing must be taken without the cast and correlated with clinical examination.

In most cases, it is conventional to obtain follow-up x-rays after reduction to ensure that the position is maintained.

In general, in the child below 5 years of age, the follow-up is usually about 4-5 days after reduction. In the older child with a potentially unstable fracture, an x-ray would normally be taken at 7-10 days.

Further follow-up x-ray is a matter of clinical judgement, the responsibility of the treating surgeon, and tends to be longer in older children (see also Healing times).

For complete fractures of the metaphysis, redisplacement after reduction is not uncommon. It is therefore, important to take early follow-up x-rays in order to detect a possible redisplacement.

See also the additional material on posttraumatic growth disturbances.