A 35-year-old woman presents with wrist pain and swelling after a fall on an outstretched hand (FOOSH) with the forearm in supination. Clinical examination reveals tenderness over the distal radius and wrist instability. You suspect a Galeazzi fracture. Which imaging modality is most appropriate to confirm the diagnosis and assess the integrity of the distal radioulnar joint (DRUJ)?

Explanation

## Investigation of Choice for Galeazzi Fracture **Key Point:** Plain radiographs of the forearm (AP and lateral views) that include the wrist are the gold standard for diagnosing Galeazzi fractures and detecting DRUJ disruption. ### Definition of Galeazzi Fracture **High-Yield:** A Galeazzi fracture is a fracture of the distal third of the radius combined with dislocation or disruption of the distal radioulnar joint (DRUJ). It is sometimes called a "fracture of necessity" because the DRUJ must be disrupted for the fracture to occur. ### Why Plain Radiographs Are Diagnostic 1. **Visualization of key components:** - Distal radial fracture (typically distal third) - Dorsal displacement of the ulnar head (indicating DRUJ disruption) - Widening of the DRUJ space 2. **Optimal views:** - **AP view:** Shows radial fracture and ulnar head position - **Lateral view:** Demonstrates dorsal angulation of the radial fracture and dorsal ulnar head displacement - **Wrist views:** Ensure the entire DRUJ is visualized **Clinical Pearl:** The key finding is dorsal displacement of the ulnar head relative to the sigmoid notch of the radius. This is best appreciated on the lateral view and confirms DRUJ disruption. ### Anatomical Basis | Component | Finding on Radiographs | |---|---| | Radial fracture | Distal third, often with dorsal angulation | | DRUJ disruption | Dorsal displacement of ulnar head, widened DRUJ space | | Associated injuries | Possible triangular fibrocartilage complex (TFCC) tear | **Mnemonic:** **GALEAZZI** = **G**aleazzi fracture = **A**ssociated **L**oss of **E**xternal **A**lignment at **Z**ygapophyseal (DRUJ) joint. ### Why Other Investigations Are Not First-Line - **CT:** Useful for surgical planning in comminuted fractures, but not needed for initial diagnosis - **MRI:** Excellent for soft tissue assessment (TFCC tears), but not required to confirm the fracture and DRUJ disruption - **Fluoroscopic stress testing:** Invasive, requires anesthesia, and not necessary when plain radiographs clearly show the dislocation ### Management Implications Once a Galeazzi fracture is confirmed on plain radiographs, the diagnosis is established and treatment (typically surgical fixation of the radius with DRUJ reduction and stabilization) can proceed without further imaging.