A 35-year-old female presents to the orthopedic clinic 3 weeks after a fall on an outstretched hand with wrist extension. She complains of wrist pain, swelling over the distal forearm, and weakness of grip. On examination, there is tenderness over the distal radius and loss of wrist supination. X-rays show a fracture of the distal third of the radius with an associated dislocation of the distal radioulnar joint (DRUJ) confirmed on CT imaging. What is the most likely diagnosis?

Explanation

## Diagnosis: Galeazzi Fracture-Dislocation **Key Point:** A Galeazzi fracture-dislocation is defined as a fracture of the distal third of the radius (within the junction of the middle and distal thirds) combined with dislocation of the distal radioulnar joint (DRUJ). This is a relatively uncommon but clinically significant injury. ### Clinical Presentation - **Mechanism:** FOOSH with wrist extension, or direct blow to distal forearm - **Primary fracture:** Distal third of radius (typically at the junction of middle and distal thirds) - **Associated injury:** DRUJ dislocation (usually dorsal) - **Symptoms:** Wrist pain, swelling, loss of supination, grip weakness - **Key finding:** Prominence of the ulnar head ("ulnar head sign") ### Comparative Features: Monteggia vs. Galeazzi | Feature | Monteggia | Galeazzi | |---------|-----------|----------| | **Primary fracture** | Ulna (proximal/middle third) | Radius (distal third) | | **Associated dislocation** | Radial head (anterior) | DRUJ (dorsal) | | **Mechanism** | FOOSH, direct blow to ulna | FOOSH with wrist extension | | **Loss of motion** | Pronation/supination | Supination (more prominent) | | **Frequency** | More common | Less common (~5% of forearm fractures) | | **Prognosis if missed** | Chronic instability, poor outcome | Chronic DRUJ instability, arthritis | ### Anatomical Basis The DRUJ is stabilized by: 1. **Triangular fibrocartilage complex (TFCC)** 2. **Interosseous membrane (IOM)** 3. **Radioulnar ligaments** A distal radial fracture disrupts these stabilizers, leading to DRUJ dislocation. **High-Yield:** The DRUJ dislocation in Galeazzi can be subtle on plain radiographs. Look for: - Widening of the DRUJ space (>5 mm is abnormal) - Dorsal displacement of the ulnar head - Loss of the normal overlapping of radius and ulna on the AP view **Clinical Pearl:** The "ulnar head sign"—a prominent ulnar styloid palpable on the dorsal aspect of the wrist—is a clinical clue to DRUJ dislocation. Always compare with the contralateral wrist. **Mnemonic:** **GALE** = **G**aleazzi = **A**distal **L**ocation of radius fracture + **E**xtra-articular DRUJ dislocation ### Management 1. **Closed reduction** of the DRUJ (usually reduces with radial fracture reduction) 2. **ORIF of the distal radial fracture** (compression plate, typically volar Henry approach) 3. **Assessment of DRUJ stability** after reduction 4. **If DRUJ remains unstable:** Consider TFCC repair or temporary pinning (K-wire across DRUJ for 4–6 weeks) 5. **Early mobilization** after fixation to prevent stiffness **Warning:** Missing the DRUJ dislocation or inadequate reduction leads to chronic DRUJ instability, painful clicking, loss of supination, and early post-traumatic arthritis. This is the most common reason for poor outcomes in Galeazzi fractures.