Regarding the classification and management principles of supracondylar fractures of the humerus in children, all of the following statements are correct EXCEPT:

Explanation

## Gartland Classification of Supracondylar Fractures ### Type I, II, III Definitions | Type | Displacement | Cortical Contact | Management | | --- | --- | --- | --- | | I | Minimal/no displacement | Intact | Immobilization (collar & cuff, sling) | | II | Angulated, displaced | Partial cortical contact | Closed reduction ± pinning | | III | Completely displaced | No cortical contact | CRPP or open reduction | **Key Point:** Type III fractures have complete loss of cortical continuity between proximal and distal fragments — this is the defining feature. ## Treatment Algorithm ```mermaid flowchart TD A[Supracondylar Fracture]:::outcome --> B{Gartland Type?}:::decision B -->|Type I| C[Immobilization]:::action B -->|Type II| D{Reducible?}:::decision B -->|Type III| E[CRPP or ORIF]:::action D -->|Yes| F[Closed Reduction + Pinning]:::action D -->|No| E C --> G[Follow-up X-rays]:::action F --> H[Pin removal 3-4 weeks]:::action E --> H ``` **High-Yield:** CRPP is the gold standard for Type II (irreducible or unstable) and Type III fractures. It provides anatomic reduction and stability while avoiding open surgery. ## Deformity Patterns **Clinical Pearl:** In supracondylar fractures: - **Lateral angulation** is more common than medial angulation - This occurs because the distal fragment is pulled anteriorly and laterally by the brachialis muscle and the pull of the proximal fragment - Lateral angulation is associated with a higher risk of nerve injury (especially radial nerve) ## Nerve Injury Frequency **Warning:** The most commonly injured nerve is the **RADIAL nerve** (2–6%), NOT the posterior interosseous nerve (PIN). | Nerve | Frequency | Mechanism | | --- | --- | --- | | Radial nerve | 2–6% (most common) | Stretching from anterior displacement | | Median nerve (AIN) | 1–2% | Stretching | | Ulnar nerve | <1% | Rare; may occur iatrogenically during pinning | | Posterior interosseous nerve | <1% | Rare in supracondylar fractures | **Key Point:** PIN injury is rare in supracondylar fractures and is NOT the most frequent nerve injury. The radial nerve is at highest risk due to its anterior and lateral course relative to the fracture site. ## Why Option 3 Is Wrong The posterior interosseous nerve (PIN) is a branch of the radial nerve that innervates the posterior compartment of the forearm. PIN injury is **extremely rare** in supracondylar fractures (<1%). The **radial nerve** itself is the most commonly injured nerve (2–6%), and it is the main trunk, not the PIN branch, that is at risk in this fracture pattern.