A 28-year-old male presents to the emergency department 2 hours after a fall on his outstretched hand with forced pronation. Clinical examination reveals swelling and deformity of the left forearm. X-rays show a fracture of the proximal third of the radius with an anterior angulation, and a posterior dislocation of the radial head. What is the most appropriate next step in management?

Explanation

## Monteggia Fracture-Dislocation: Management Algorithm **Key Point:** A Monteggia fracture-dislocation is a fracture of the ulna (typically proximal or middle third) combined with anterior or posterior dislocation of the radial head. The radial head dislocation is often missed on initial radiographs and is the hallmark of this injury. ### Mechanism & Classification Monteggia fractures result from a fall on an outstretched hand with forced pronation (anterior dislocation) or supination (posterior dislocation). The classic presentation is: - Ulnar fracture (usually proximal or middle third) - Radial head dislocation (anterior in ~80%, posterior in ~20%) ### Management Principles **High-Yield:** The key to successful management is: 1. **Restore length and alignment of the ulna** — this is the primary goal 2. **Reduce the radial head** — often reduces spontaneously once ulnar length is restored 3. **Assess stability** — if the radial head remains dislocated after ulnar fixation, proceed to open reduction ### Optimal Treatment Sequence ```mermaid flowchart TD A[Monteggia Fracture-Dislocation]:::outcome --> B[ORIF of Ulna with Plate]:::action B --> C{Radial Head Reduced?}:::decision C -->|Yes| D[Assess Stability]:::decision C -->|No| E[Open Reduction of Radial Head]:::action D -->|Stable| F[Immobilize 4-6 weeks]:::action D -->|Unstable| G[Consider Annular Ligament Repair]:::action E --> H[Immobilize 4-6 weeks]:::action ``` **Clinical Pearl:** In adults, the standard of care is **open reduction and internal fixation (ORIF) of the ulnar fracture using a compression plate** (3.5 mm dynamic compression plate or locking plate). This restores anatomic length and alignment, and frequently allows spontaneous reduction of the radial head dislocation. If the radial head remains dislocated after ulnar fixation, direct open reduction is required. **Warning:** Closed reduction alone has a high rate of redislocation and malunion in adults. Operative fixation is the gold standard. ### Why Option 2 (Closed Reduction First) Is Incorrect While closed reduction of the radial head may be attempted, it is unstable and frequently redislocates. The primary pathology is the **ulnar fracture**, not the radial head dislocation. Fixing the ulna first restores the anatomic relationship and provides stability to the radial head. **Mnemonic:** **ORIF First, RH Second** — Operative fixation of the ulna is the priority; the radial head often follows. [cite:Rockwood & Green's Fractures in Adults Ch 28]