A 35-year-old man presents with a forearm fracture after a fall on an outstretched hand. Radiographs show a fracture of the distal radius with clinical evidence of wrist instability and loss of the normal radial bow. Which feature best distinguishes this injury from a Monteggia fracture?

Explanation

## Clinical Presentation: Galeazzi vs Monteggia **Key Point:** The **location of the fracture** and the **type of associated soft-tissue injury** are the critical discriminators. In this case, the distal radius fracture with wrist instability is pathognomonic for Galeazzi, not Monteggia. ### Clinical Scenario Analysis The stem describes: - Distal radius fracture ✓ (Galeazzi location) - Wrist instability ✓ (DRUJ disruption) - Loss of radial bow ✓ (indicates radius fracture) - Radial head is **not mentioned as dislocated** ✓ (stays in situ in Galeazzi) ### Galeazzi Fracture: Defining Features 1. **Fracture location:** Distal third of radius (typically within 7 cm of wrist) 2. **Associated injury:** Disruption of distal radioulnar joint (DRUJ) 3. **Radial head:** Remains in anatomic position (no dislocation) 4. **Clinical signs:** Wrist swelling, loss of pronation/supination, prominence of ulnar head 5. **Mechanism:** Fall on supinated forearm or direct blow ### Monteggia Fracture: Defining Features 1. **Fracture location:** Proximal or middle third of ulna 2. **Associated injury:** Anterior dislocation of radial head 3. **Radial head:** Dislocated (must be reduced) 4. **Clinical signs:** Elbow swelling, limited pronation, radial head palpable anteriorly 5. **Mechanism:** Fall on pronated forearm ### Comparison Table: Discriminating Features | Feature | Galeazzi | Monteggia | |---------|----------|----------| | **Fractured bone** | Radius (distal 1/3) | Ulna (proximal/middle 1/3) | | **Associated injury** | DRUJ disruption | Radial head dislocation | | **Radial head on X-ray** | In situ, normal position | Dislocated anteriorly | | **Wrist findings** | Instability, DRUJ widening | Usually normal | | **Elbow findings** | Usually normal | Radial head prominence | | **Loss of radial bow** | Yes (radius fractured) | No (ulna fractured) | **High-Yield:** In Galeazzi, the **radial head remains in its normal position**—the injury is at the **wrist (DRUJ)**, not the elbow. In Monteggia, the **radial head is dislocated**—the injury is at the **elbow**, not the wrist. **Clinical Pearl:** Galeazzi is sometimes called the "fracture of necessity" (though Monteggia also claims this title). The key bedside finding is **wrist instability with loss of pronation/supination**, whereas Monteggia presents with **elbow deformity and radial head prominence**. **Mnemonic:** **"Galeazzi = Wrist; Monteggia = Elbow"** — Galeazzi injuries affect the **distal radioulnar joint** (wrist), while Monteggia injuries affect the **radial head** (elbow).