Causes / typical injury mechanism: Supracondylar humerus fractures are typically caused by a fall onto an outstretched arm, causing a hyperextension load on the elbow. A more uncommon mechanism of injury is a fall directly onto the olecranon of a flexed elbow.

Classic history and presentation: The classic presentation is a child who sustains a fall and trauma to the extremity, with immediate onset of pain and unwillingness to move the elbow.

Prevalence: This is the most common fracture of the elbow in children.

• Age – Seen most in children aged 3-8 years.
• Sex / gender – Occurs with equal prevalence in both sexes.

Pathophysiology: The olecranon hyperextends into the olecranon fossa, acting as a fulcrum and leading to anterior tension force and failure of the distal humerus anteriorly.

Grade / classification system: Modified Gartland classification of extension-type fractures

• Type I – Nondisplaced
• Type II – Displaced with intact posterior hinge
• Type III – Completely displaced with no intact cortices
• Type IV – Multidirectional instability (determined by examination under anesthesia)

Classification of vascular status

• Hand well perfused (warm, pink), radial pulse present
• Hand well perfused (warm, pink), radial pulse absent
• Hand poorly perfused (cool, blue, blanched), radial pulse absent