Lesson

Investigation

X-ray

All patients presenting with elbow pain after trauma should have x-rays obtained. These should include antero-posterior (AP) and lateral images. If a proximal radius fracture is suspected, an oblique radial head view can help by removing the osseous overlap of the radial head and coronoid.

Click on the following images to view normal, labelled, x-ray images of the elbow.

  • Normal AP elbow

  • Normal lateral elbow

  • Normal oblique elbow

On the lateral image, a line down the anterior cortex of the humerus should pass through the middle third of the capitellum (there is a high degree of suspicion of a supracondylar fracture when the capitellum is posterior to this line). The long axis of the radius (a horizontal line along the centre of the radial shaft) on the lateral image should also pass through the capitellum.

It can be difficult to obtain ideal views on the athlete with a painful elbow following trauma. Splints and other materials may also adversely affect the image quality.

Bone injuries might not always be easily identified on plain films. There are a number of soft tissue features that can suggest an occult fracture. One of these is the ‘sail sign’ (i.e. anterior and posterior fat-pad displacement).

André Pedrinelli

Orthopaedic – Prosthetics / Sports Medicine

Other imaging

MRI is generally the modality of choice for further assessment of the elbow. The main indications for an MRI are:

  • Clinical signs of fracture, but no radiographic evidence (the so-called occult fracture)
  • Ligamentous injuries
  • Tendon injuries
  • Loose bodies
  • Osteochondral lesions

Computed tomography (CT) is useful for assessing intra-articular fractures and to help with pre-operative planning in complex cases. In some cases, 3D reconstruction can improve the understanding of fracture pattern.

Ultrasound scans (USS) can also be very useful in assessing the tendons around the elbow. Tendinopathy, and tendon ruptures, are typically clinical diagnoses but can also be diagnosed using USS. This is also a good tool for the assessment of the peripheral nerves about the elbow.

Click on the following images to view normal, labelled, images of the elbow.

  • Normal common extensor origin

    Observe the uniform thickness and tight packed fibrillar pattern.

Click on the following link to read more about the use of MRI to evaluate the elbow.