Location of the Anatomical Snuff Box
The anatomical snuff box is located on the radial (lateral) side of the wrist, bounded by the tendons of the abductor pollicis longus and extensor pollicis brevis laterally, and the extensor pollicis longus tendon medially 1, 2, 3.
Anatomical Boundaries and Contents
The snuff box is a triangular depression that becomes visible when the thumb is extended:
- Lateral border: Tendons of abductor pollicis longus (APL) and extensor pollicis brevis (EPB)
- Medial border: Tendon of extensor pollicis longus
- Floor: Scaphoid bone and trapezium
- Key vascular structure: The radial artery crosses through the floor of the anatomical snuff box 3, 4
Clinical Relevance
This anatomical region has significant clinical importance:
Vascular Access Site
The snuff box is increasingly used for distal radial access (DRA) in interventional procedures 5, 6. A snuff-box fistula is defined as an autologous arteriovenous fistula constructed between a branch of the radial artery and an adjacent vein in this location 1.
Recent evidence shows the radial artery diameter in the snuff box averages 2.65 ± 0.64 mm, with 80% of specimens exceeding 2.3 mm—suitable for distal radial catheterization 3. The cephalic vein diameter of at least 2 mm (present in 88.8% of cases) supports arteriovenous fistula creation 3.
Anatomical Variations
Be aware that the radial artery demonstrates a tortuous course in 73.3% of cases (more common on the right side), which should be considered during clinical interventions 3. In rare cases, the radial artery may run superficially over the snuff box rather than beneath the tendons 4.
Common Pitfall
The APL tendon shows significant variation, with single tendons in only 42% of cases and multiple slips (2-5 tendons) in 58% 2. This variability can affect surgical planning and identification of anatomical landmarks.