Regarding the classification, reduction technique, and complications of supracondylar fractures of the humerus in children, all of the following statements are correct EXCEPT:

Explanation

## Supracondylar Fracture Classification, Mechanism, and Imaging ### Gartland Classification | Type | Description | Displacement | |------|-------------|---------------| | **Type I** | Undisplaced | Minimal or no displacement | | **Type II** | Partially displaced | Intact posterior cortex, angulation present | | **Type III** | Completely displaced | No cortical contact, complete loss of alignment | **Key Point:** Type III fractures show complete loss of cortical contact between proximal and distal fragments, making them the most unstable and requiring operative fixation. ### Mechanism of Injury **High-Yield:** Hyperextension injuries account for 95–98% of supracondylar fractures. The child falls on an outstretched hand (FOOSH) with the elbow extended, causing the distal fragment to be driven posteriorly. ### Imaging Findings **Anterior Humeral Line:** - On lateral X-ray, a line drawn along the anterior cortex of the humerus should pass through the middle third of the capitellum - Loss of this relationship indicates fracture displacement and angulation - This is a sensitive and specific sign of displacement ### Vascular Complications **Clinical Pearl:** Brachial artery injury is more commonly associated with **flexion-type** supracondylar fractures (rare, ~5% of cases) and **medial angulation** of the fracture. However, the statement that "medial angulation is associated with higher risk of brachial artery injury" is **NOT universally supported** as the primary risk factor. **Warning:** The most important risk factor for vascular injury is the degree of displacement and the mechanism. Flexion-type fractures (which inherently have medial angulation) carry higher vascular risk, but medial angulation alone in an extension-type fracture is not the primary determinant of brachial artery injury risk. **Key Point:** Anterior displacement of the proximal fragment and complete displacement (Type III) are the main risk factors for brachial artery injury, not specifically medial angulation. ### Summary of True Statements 1. **Gartland Type III** = completely displaced, no cortical contact ✓ 2. **Hyperextension** = 95–98% of cases ✓ 3. **Anterior humeral line loss** = reliable sign of displacement ✓ 4. **Medial angulation** = NOT the primary risk factor for brachial artery injury ✗