A 35-year-old woman presents with acute pain and swelling of the right forearm following a fall on an outstretched hand in supination. Clinical examination reveals tenderness over the distal radius and wrist, with prominence of the distal ulnar head. X-rays of the wrist show a fracture of the distal third of the radius with dorsal angulation, and the distal radioulnar joint (DRUJ) is dislocated. What is the most likely diagnosis and the key management principle?

Explanation

## Galeazzi Fracture: Anatomy, Diagnosis, and Management ### Definition and Mechanism **Key Point:** A Galeazzi fracture is a fracture of the distal third of the radius (typically in the distal 25%) combined with dislocation of the distal radioulnar joint (DRUJ). It is sometimes called a "fracture of necessity" because ORIF of the radius is mandatory—closed reduction alone will fail. **Mnemonic:** **GALEAZZI = Distal Radius + DRUJ dislocation** (Remember: "Galeazzi is at the wrist end") The mechanism is typically a fall on an outstretched hand in supination, causing: 1. Fracture of the distal radial shaft 2. Disruption of the interosseous membrane 3. Dislocation of the distal ulna from the sigmoid notch of the radius (usually dorsal) ### Comparison: Monteggia vs. Galeazzi | Feature | Monteggia | Galeazzi | |---------|-----------|----------| | **Bone fractured** | Ulna (proximal/middle third) | Radius (distal third) | | **Joint dislocated** | Proximal radioulnar joint (radial head) | Distal radioulnar joint (distal ulna) | | **Dislocation direction** | Anterior (Type I) or posterior (Type II) | Usually dorsal | | **Mechanism** | Fall on outstretched hand in pronation | Fall on outstretched hand in supination | | **Management** | ORIF ulna; radial head reduces automatically | ORIF radius; DRUJ reduces automatically | ### Management Principles **High-Yield:** The critical principle is that the DRUJ dislocation is a **secondary injury** caused by the radial fracture and disruption of the interosseous membrane. Once the radius is anatomically reduced and fixed with a plate, the DRUJ will reduce spontaneously in most cases. **Clinical Pearl:** Galeazzi fractures are "fractures of necessity"—they almost always require ORIF because: - Closed reduction alone leads to re-displacement and chronic DRUJ instability - The interosseous membrane is disrupted, preventing passive reduction - Early mobilization is essential to prevent stiffness ### Treatment Algorithm ```mermaid flowchart TD A[Galeazzi Fracture Diagnosed]:::outcome --> B[ORIF Distal Radius with Plate & Screws]:::action B --> C{DRUJ Stable After Reduction?}:::decision C -->|Yes - Most cases| D[Immobilize in neutral rotation 4-6 weeks]:::action C -->|No - Rare| E[Percutaneous DRUJ pinning or surgical repair]:::action D --> F[Early mobilization protocol]:::action E --> F F --> G[Good functional outcome with pronation/supination preserved]:::outcome ``` ### Surgical Technique 1. **Approach:** Volar Henry approach or dorsal Thompson approach 2. **Fixation:** 3.5 mm dynamic compression plate (DCP) or locking compression plate (LCP) with minimum 6 cortices (3 screws) distal and proximal to the fracture 3. **DRUJ reduction:** Achieved by restoring radial length and alignment; manual reduction of the ulna head if needed 4. **Immobilization:** Above-elbow cast or splint in neutral rotation for 4–6 weeks 5. **Special case:** If DRUJ remains unstable after radial fixation (rare), percutaneous pinning of the DRUJ or surgical repair of the triangular fibrocartilage complex (TFCC) may be needed **Warning:** Do NOT attempt closed reduction and casting—this leads to loss of reduction, chronic DRUJ dislocation, loss of pronation/supination, and poor functional outcome. [cite:Rockwood and Green's Fractures in Adults Ch 25; Campbell's Operative Orthopaedics 13e Ch 58]