A 32-year-old male construction worker falls from a 4-meter height onto his outstretched right hand. On examination, the wrist is swollen and deformed. X-ray shows a fracture of the distal radius with dorsal displacement and angulation of the distal fragment, along with an associated fracture of the ulnar styloid. The distal radial articular surface is not involved. What is the classification of this fracture?

Explanation

## Fracture Classification This is a **Colles' fracture**, the most common type of distal radius fracture. ### Key Diagnostic Features **Key Point:** Colles' fracture is defined by dorsal displacement and dorsal angulation of the distal radial fragment, typically with an associated ulnar styloid fracture. ### Mechanism & Pattern 1. **Mechanism**: Fall on outstretched hand (FOOSH) with wrist in extension 2. **Fracture location**: Distal radius, typically 2–3 cm proximal to the wrist joint 3. **Displacement**: Dorsal (posterior) displacement of distal fragment 4. **Associated injury**: Ulnar styloid fracture in ~50% of cases 5. **Articular involvement**: Intra-articular extension is common but NOT required for diagnosis ### Comparison with Other Distal Radius Fractures | Feature | Colles' | Smith's | Barton's | Chauffeur's | |---------|---------|----------|-----------|-------------| | **Mechanism** | FOOSH, wrist extended | FOOSH, wrist flexed | High-energy fall | Direct blow to radial styloid | | **Displacement** | Dorsal | Volar (palmar) | Volar with subluxation | Radial styloid fracture | | **Articular involvement** | Often | Often | Always | No | | **Stability** | Usually stable | Usually stable | Unstable | Stable | | **Classic deformity** | "Dinner fork" | "Reverse dinner fork" | Fracture-dislocation | Isolated styloid | **High-Yield:** Colles' fracture accounts for ~90% of all distal radius fractures and is the most common fracture in the elderly (osteoporotic bone). ### Clinical Pearl The "dinner fork" deformity (dorsal prominence) is pathognomonic for Colles' fracture on lateral X-ray view and is one of the most recognizable fracture patterns in orthopedics. ### Mnemonic **COLLES = Dorsal displacement** - **C**ommon (most frequent distal radius fracture) - **O**utward (dorsal) displacement - **L**ateral (radial) styloid often involved - **L**ess common with volar displacement - **E**lderly (osteoporotic) patients - **S**tyloid of ulna fractured [cite:Rockwood & Green's Fractures in Adults Ch 16]