A 28-year-old male carpenter from Delhi presents with wrist pain and swelling over the dorsal aspect of the wrist following a fall on an outstretched hand (FOOSH) 3 days ago. On examination, there is tenderness in the anatomical snuffbox and 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:** Suspected scaphoid fractures with normal initial radiographs require immobilization and repeat imaging, as 15–25% of scaphoid fractures are radiographically occult at presentation. ### Why Immobilization First? The patient has classic signs of scaphoid fracture: - Mechanism: FOOSH injury - Anatomical snuffbox tenderness - Pain on axial thumb loading - Normal plain radiographs (common in non-displaced or minimally displaced fractures) **High-Yield:** In suspected scaphoid fractures with normal initial X-rays, the standard of care is **clinical immobilization** (thumb spica cast) and **repeat radiographs at 10–14 days**. Callus formation becomes visible on repeat films, confirming the diagnosis. ### Management Algorithm ```mermaid flowchart TD A[FOOSH + Snuffbox tenderness]:::outcome --> B{Plain X-rays normal?}:::decision B -->|Yes| C[High suspicion for occult fracture]:::outcome C --> D[Immobilize in thumb spica cast]:::action D --> E[Repeat X-rays at 10-14 days]:::action E --> F{Fracture visible?}:::decision F -->|Yes| G[Continue immobilization 8-12 weeks]:::action F -->|No| H{Persistent symptoms?}:::decision H -->|Yes| I[MRI or CT for confirmation]:::action H -->|No| J[Discharge; soft tissue injury]:::outcome B -->|No| K[Fracture confirmed]:::outcome K --> G ``` ### Timing of Imaging | Imaging | Timing | Sensitivity | Use Case | |---------|--------|-------------|----------| | Plain X-ray (initial) | Day 0 | 60–80% | First-line; may miss non-displaced | | Repeat X-ray | Day 10–14 | 90–95% | Callus visible; cost-effective | | MRI | Day 0–3 | 95–99% | Early diagnosis if high suspicion; expensive | | CT (3D) | Day 0+ | 98–100% | Non-union/malunion assessment; not first-line | **Clinical Pearl:** Immobilization serves dual purpose: (1) prevents displacement of an occult fracture, and (2) allows callus formation to become radiographically apparent. ### Why NOT the Other Options? - **MRI immediately:** While sensitive, MRI is expensive and not first-line for uncomplicated suspected scaphoid fractures. Reserve for persistent symptoms after repeat X-rays or high-risk patients (athletes, surgeons). - **CT 3D:** Overkill for initial diagnosis; used for complex fractures, non-union, or malunion assessment. - **No immobilization:** Risks displacement and delayed union; contradicts standard of care. **Mnemonic:** **CAST FIRST, REPEAT LATE** — Immobilize immediately, image again at 10–14 days.