Presentation
Fall onto the outstretched hand while riding a bike.
Patient Data
Elbow radiographs reveal discrete lucent fracture lines on the frontal plane. The lateral radiograph shows a minimally posteriorly displaced supracondylar fracture of the humerus.
Also, there is a mild elbow joint effusion, especially around the posterior fat pad.
These findings describe a Gartland type I supracondylar fracture.
The anterior humeral line was assessed and identified as not intersecting the middle third of the capitellum ossification center. In children older than 4 years of age, this finding is suggestive of distal humeral fractures, mostly supracondylar fractures.
The presence of the posterior fat pad sign is marked by the white arrowheads.
Case Discussion
Supracondylar fractures are the most common elbow fractures in children. Fall onto the outstretched hand with the elbow in full extension is the main mechanism of injury.
Gartland type I fractures are undisplaced or minimally displaced supracondylar fractures. Sometimes, fracture lines are difficult to be seen on Gartland type I fractures. In these cases, it is important to look for indirect signs of a supracondylar fracture, such as:
- presence of elbow joint effusion;
- the anterior humeral line does not intersect the middle third of the capitellum.
In the present case, there was mild elbow joint effusion. Also, the anterior humeral line was passing through the anterior third of the capitellum, although this can be normal, it's quite uncommon for children older than 4 years of age.
Finally, it's important to be familiar with the elbow ossification centers when assessing a pediatric elbow. In this case, the capitellum, radial head, and medial epicondyle were visible as expected for the patient's age and without signs of dislocation.