A 28-year-old male laborer presents to the emergency department with pain and swelling over the dorsal aspect of his right wrist after a fall on an outstretched hand (FOOSH) 6 hours ago. On examination, he has tenderness in the anatomical snuffbox with pain on axial loading of the thumb. Plain radiographs (PA, lateral, and scaphoid views) appear normal. What is the most appropriate next step in management?

Explanation

## Clinical Presentation & Diagnosis **Key Point:** Scaphoid fractures are notoriously difficult to detect on initial plain radiographs, with up to 20% of fractures appearing normal on the first set of images. The clinical diagnosis (snuffbox tenderness + FOOSH mechanism) is sufficient to warrant empiric immobilization. ## Management Algorithm ```mermaid flowchart TD A[FOOSH injury + snuffbox tenderness]:::outcome --> B{Plain radiographs normal?}:::decision B -->|Yes| C[Treat as scaphoid fracture]:::action C --> D[Thumb spica immobilization]:::action D --> E[Repeat X-rays at 10-14 days]:::action E --> F{Fracture line visible?}:::decision F -->|Yes| G[Continue immobilization 8-12 weeks]:::action F -->|No| H[Consider MRI/CT if high suspicion]:::action B -->|No| I[Confirm fracture type]:::action I --> J[Assess displacement/comminution]:::action ``` ## Why Empiric Immobilization? 1. **Fracture healing depends on early immobilization**, not delayed diagnosis 2. **Avascular necrosis (AVN) risk** increases with delay; proximal pole fractures are particularly vulnerable 3. **Repeat radiographs at 10–14 days** show callus formation and confirm the diagnosis 4. **Cost-effective**: thumb spica cast is inexpensive; MRI upfront is not standard first-line **High-Yield:** The "clinical diagnosis" of scaphoid fracture (mechanism + snuffbox tenderness + normal initial X-rays) is an AIIMS/NEET PG favorite. Immobilization is the standard of care pending radiographic confirmation. ## Imaging Timeline | Timing | Finding | Action | |--------|---------|--------| | 0–6 hours (acute) | Plain films often negative | Empiric thumb spica cast | | 10–14 days | Callus appears on repeat X-rays | Confirms fracture; continue immobilization | | If still unclear | MRI shows marrow edema/fracture line | Guides further management | **Clinical Pearl:** Scaphoid fractures heal slowly (8–12 weeks for non-displaced, 12–16 weeks for displaced) due to retrograde blood supply. Early immobilization prevents displacement and AVN. [cite:Rockwood & Green's Fractures in Adults Ch 8]