Causes / typical injury mechanism: Lateral condyle fracture is the second most common fracture of the elbow among pediatric populations. It involves a fracture of the distal humerus affecting the lateral condyle, typically caused by a fall on an outstretched hand. Specifically, medial stress can cause the soft tissue structures that insert on the lateral condyle to avulse the bony structure. An alternative mechanism of injury is a fall on the palm while the elbow is flexed.

Classic history and presentation: The injury commonly occurs in young children after a fall; they typically present with pain localized to the area around the lateral condyle of the humerus, as well as limited range of motion.

Prevalence: The mean age of patients is approximately 6 years, and the injury accounts for up to 15% of distal humerus fractures among the pediatric population, second to supracondylar fractures of the humerus.

Grade / classification system: Via the Weiss classification, the fracture is classified as type 1, 2, or 3, based upon the degree of displacement and the level of injury to the articular surface. The Milch classification depends on the location of the fracture line relative to the trochlear groove. The Song classification described 5 different types of fracture, with type 5 referring to the most displaced and rotated fracture fragment and type 1 referring to a nondisplaced fracture.