Elbow series (pediatrics)

The elbow series for pediatrics is a set of radiographs taken to investigate elbow joint pathology, often in the context of trauma. It usually comprises an anteroposterior and lateral projection in order to minimize radiation dose to the patient. Depending on the department and clinical indication, other non-standard, modified projections may also be done.

Being familiar with the order of elbow ossification is important in assessing the elbow joint in a pediatric patient to ensure that a normal ossification center is not mistaken for an epicondylar fracture.

Indications

Elbow x-rays are indicated for a variety of settings including:

• trauma
• bony tenderness
• suspected fracture of the proximal radius and ulna
• suspected fracture of the distal humerus
• radial head dislocations
• obvious deformity
• detecting joint effusions (fat pad sail sign)
• arthritis
• infection

Projections

Standard projections

• anteroposterior view
  • demonstrates distal humerus, proximal radius and ulna
  • shows both the medial and lateral epicondyles in profile
• lateral view
  • best demonstrates the ulna-trochlear joint, coronoid process, and the olecranon process
  • used to assess both the anterior humeral line and the radiocapitellar line

Modified trauma projections

Where patients are in considerable amount of pain, these projections may be useful in obtaining diagnostic images whilst requiring little to no patient movement.

• horizontal beam anteroposterior view
• horizontal beam lateral view

Patient preparation

Patients should remove any jewelry or clothing over the arm to avoid artifact.

Gonadal shielding

The use of gonadal and fetal shielding has been deemed as non-beneficial to patients' health in current evidences  and may or may not be useful for pediatric extremity imaging. Placing gonadal shielding can increase the examination time and may cause the child more stress. However, shielding can also reduce the family's anxiety in relation to radiation dose. Therefore, the decision to use shielding will depend on departmental protocols and the radiographer's judgment.

Tips for pediatric elbow radiography

The major difficulty in pediatric radiography relates to:

• motion artifact

To overcome this, a variety of techniques can be used :

• distract the patient with toys, games and/or conversation
• using the swaddling technique; wrap the child in a blanket to promote comfort and sleep
• have the child sit on the carer's lap to ensure they are comfortable

Immobilization techniques

Children will find it difficult to keep their arm still; particularly if the limb is injured. One option is to have a carer or radiographer hold the child's arm at the distal forearm and proximal arm. For patients who are unable to fully extend their elbow for the anteroposterior view, using an immobilization sponge to elevate the distal forearm can be useful without causing too much distortion in the image.