Anatomical Snuff Box
Original Editor - Merihan Hussein
Top Contributors - Kim Jackson, Merihan Hussein, Vidya Acharya, Mmesoma Eyisi, Rachael Lowe, George Prudden and Carina Therese Magtibay
Description
The Anatomical Snuffbox (also known as the radial fossa), is a small triangular superficial depression in the skin found on the radial aspect of the wrist.[1] It is located at the level of the carpal bones and is best seen when the thumb is held in abduction and wrist in ulnar deviation. The triangle's base lies parallel to the lateral border of the radial head, while the apex point to the first metacarpophalangeal joint[2]. In the past, this small depression was used to hold tobacco before inhaling through the nose, hence it was given the name ‘snuffbox’[3].
Anatomy
The anatomy of the Anatomical Snuffbox includes the borders, the base, the roof, and the contents. [1]
Borders: Lateral (radial) edge is bounded by the tendons of the abductor pollicis longus (APL) and extensor pollicis brevis muscles (EPB), and medial (ulnar) is bounded by the extensor pollicis longus muscle tendon (EPL).[2]
Base: It consists of the distal margin of the extensor muscles retinaculum and the attachment of the tendons of the extensor pollicis longus and extensor pollicis brevis muscle. The base of the anatomical snuffbox contains various bony landmarks. From proximal to distal, they are: radial styloid, scaphoid, trapezium, base of the thumb metacarpal. They are palpable with the hand in ulnar deviation with the thumb extension.[2]
Roof: It consists of the skin and the superficial fascia.
Contents: The radial artery passes through the floor of the anatomical snuffbox obliquely, running deep between the heads of the adductor pollicis muscles. Also, the Cephalic vein and the superficial branch of the radial nerve are found on the roof of the anatomical snuffbox.[2]
Clinical relevance
Fractures of the Scaphoid: Anatomical snuffbox is clinically significant for assessing scaphoid fracture. [2]In the anatomical snuffbox, the scaphoid, and the radius articulate to form part of the wrist joint. In the event of a blow to the wrist (falling on an outstretched hand), the scaphoid takes most of the force. If localized pain is reported in the anatomical snuffbox, a scaphoid fracture is the most likely cause.[1] The hallmark of anatomic snuffbox tenderness is highly sensitive for scaphoid fractures but lacks specificity. Due to lower specificity, patients with snuffbox tenderness should undergo radiographic studies of the wrist. The effect of missing fracture would subsequently affect the quality of life due to suseptibilty to non-union. Also, this fracture location is important in determining treatment options to prevent avascular necrosis of the bone due to the unique blood flow to the scaphoid.[2]
Radial artery aneurysms: are rare and are usually associated with trauma, penetrating, or iatrogenic. They are less common than aneurysms of the ulnar artery although this discrepancy is unexplained. Incidents following blunt trauma have been described.[2]
Venous Cannulation: The dorsal lateral (radial) part of the wrist is most common for venous cannulation as the cephalic vein is more prominent there.
De Quervain Tenosynovitis: Diagnosis of DeQuervain's Tenosynovitis is related to anatomical snuffbox. The condition affects the first dorsal compartment including the muscles bounding the lateral compartment of the anatomical snuffbox (APL and EPB). Diagnosing the De Quervain tenosynovitis is made through thorough history and physical examination.[2]
Resources
The video describes the anatomical snuff box and conditions associated with the anatomical snuff box.
References
- ↑ 1.0 1.1 1.2 Cerda A, Del Sol M. Anatomical snuffbox and it clinical significance. a literature review. International Journal of Morphology. 2015 Dec 1;33(4).
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 Hallett S, Ashurst JV. Anatomy, shoulder and upper limb, hand anatomical snuff box.
- ↑ Gajurel R, Sahi R, Shrestha H, Thapa S, Khanal R. Initial Experience on Anatomical Snuff Box Approach for Coronary Angiogram & Percutaneous Coronary Intervention in a Tertiary Care Center Nepal. World Journal of Cardiovascular Diseases. 2018;8(12):578-587
- ↑ nabil ebraheimAnatomical Snuff Box - Everything You Need To Know - Dr. Nabil Ebraheim. Available from https://www.youtube.com/watch?v=LVcSlah5ksE
- ↑ KenHub. What is the anatomical snuff box? Available from: https://www.youtube.com/watch?v=Sr1_BvpWEso