Scaphoid Fracture
A fall onto an outstretched hand fractures the scaphoid across its waist, where retrograde blood supply makes the proximal fragment vulnerable to avascular necrosis and non-union, so clinical suspicion alone mandates immobilisation and repeat imaging.
In a nutshell
Scaphoid fractures occur across the waist after a FOOSH injury, and the retrograde blood supply, entering at the distal pole and running backwards to the proximal pole, means the proximal fragment is vulnerable to avascular necrosis and non-union. Because fractures are often radiographically occult, clinical suspicion (snuffbox tenderness) alone mandates immobilisation and re-imaging.
Classic presentation
A young adult with wrist pain and anatomical snuffbox tenderness after falling onto an outstretched hand, with an initially normal X-ray.
Key points
- Blood supply enters the scaphoid at the distal pole and runs retrogradely to the proximal pole, so proximal pole fractures carry the highest risk of avascular necrosis and non-union.
- A normal X-ray does not exclude a scaphoid fracture: the fracture line can be radiographically occult until bony resorption widens it over 10-14 days.
- Anatomical snuffbox or scaphoid tubercle tenderness after a FOOSH injury is immobilised as a presumed fracture, even before imaging confirms it.
- MRI is the most sensitive test for an occult fracture and is preferred where available, over waiting to repeat an X-ray.
- Displaced or proximal pole fractures are more often fixed surgically, because they are most reliant on the vulnerable retrograde blood supply.
First-line investigation
Plain wrist X-ray with dedicated scaphoid views; if normal but suspicion remains, MRI is the most sensitive next test for an occult fracture.
First-line management
Immobilise in a scaphoid or thumb spica splint or cast on clinical suspicion alone, pending definitive imaging.
Exam traps
- A normal X-ray in a patient with snuffbox tenderness after a FOOSH does not exclude a fracture: cast and re-image, do not discharge.
- The proximal pole, not the waist overall, is the highest-risk site for avascular necrosis, because it is most dependent on retrograde flow.
- Untreated non-union does not resolve: it progresses over years to SNAC wrist (scaphoid non-union advanced collapse).
- Scaphoid tubercle tenderness and axial thumb loading are additional clinical tests, not substitutes for snuffbox tenderness: use all three together.
Educational content pending clinical review. Not medical advice.