Lateral humeral condyle fracture

Lateral humeral condyle fractures also referred to simply as lateral condyle fractures (in the appropriate context), are relatively common elbow fractures that predominantly occur in children. They may be subtle but are hugely important to diagnose in a timely manner because if they are missed, they have a tendency to migrate dorsally and without treatment can have significant morbidity.

Terminology

Lateral humeral condyle fractures are usually simply termed lateral condyle fractures. They are a completely different entity to a lateral epicondyle avulsion fracture where the ossification center is avulsed.

Epidemiology

They represent ~12.5% (range 5-20%) of elbow fractures in children and are the second most common pediatric elbow fracture after supracondylar fractures.

They occur in school-age children, with a peak at 6 years .

Mechanism

These occur either after fall onto an outstretched hand, causing the radial head to impact the capitellum, or as an extensor carpi radialis longus and brevis avulsion injury after varus stress on a supinated forearm .

Radiographic features

Plain radiograph

The fracture can be underestimated on plain films and may be seen as a small sliver of bone adjacent to the proximal border of the capitellum. The fracture through the lateral condyle will have a large cartilaginous component as well as the small osseous portion.

The best view to see the lateral condyle fracture is an internal oblique and this should always be performed when a lateral condyle fracture has been diagnosed.

The displacement of the distal fracture component is best demonstrated on the internal oblique view.

The Milch and Weiss classifications have been used for these fractures. The Weiss classification uses the degree of displacement of the fracture and is a more relevant measure of severity.

CT

CT may be helpful when making an assessment of a complex fracture, but is usually not helpful in lateral condyle fracture - you should be able to get all the required information from the plain film.

MRI

MRI will delineate the whole fracture (cartilage and bone) and may help to determine any additional injury. However, it does not change management.

Radiology report

When describing a lateral condyle fracture, it is important to make comment about:

  • size of the osseous component
  • displacement (in mm) on the internal oblique
  • associated elbow joint effusion
  • any additional injury

Treatment and prognosis

The majority of these fractures are not displaced and can be treated conservatively. If there is more than 2 mm displacement on the internal oblique view, the risk of further displacement is high and operative management is required.

Operative management in displaced fractures takes the form of open reduction and internal fixation with a cannulated screw.

Differential diagnosis