Tendon sheath of abductor pollicis longus and extensor pollicis brevis
Vagina tendinum abductoris longi et extensoris brevis pollicis
- Latin synonym: Vagina tendinum musculorum abductoris pollicis longi et extensoris pollicis brevis
- Synonym: Tendinous sheath of abductor pollicis longus and extensor pollicis brevis muscles
- Related terms: Tendinous sheath of abductor longus and extensor pollicis brevis
Definition
The tendon sheath of abductor pollicis longus and extensor pollicis brevis is a shared synovial sheath that encloses both tendons as they descend on the dorsal aspect of the wrist, deep to the extensor retinaculum. The tendons pass through a bony groove on the lateral surface of the radial styloid process, within the first dorsal compartment of the wrist.
The tendon sheath extends from just above the radial styloid process to the bases of the first metacarpal and proximal phalanx of the thumb. It enables the tendons to glide smoothly and without friction during abduction and extension of the thumb.
Note that the extensor retinaculum sends fibrous septa to the underlying radius and ulna, dividing the dorsal wrist into six fibro-osseous compartments, each containing specific extensor tendons surrounded by their own synovial sheaths. The abductor pollicis longus and extensor pollicis brevis occupy the first dorsal compartment, positioned lateral to the radial styloid process.
De Quervain’s tenosynovitis
Inflammation and thickening of this common sheath leads to a condition called the De Quervain’s tenosynovitis, which presents with pain and tenderness over the radial styloid, aggravated by thumb movement or ulnar deviation of the wrist.
References
Gray, H. (2016) Gray’s Anatomy: The Anatomical Basis of Clinical Practice. 41st edn. Edited by S. Standring. New York: Elsevier. Chapter 50: Wrist and hand, pp. 879.
Drake, R.L., Vogl, A.W. and Mitchell, A.W.M. (2009). ‘Chapter 7: Hand’ in Gray’s anatomy for Students. (2nd ed.) Philadelphia PA 19103-2899: Elsevier, pp. 757; Fig. 7.95.
MickeyMed. (n.d.). Extensor retinaculum of hand. Available at: https://www.mickeymed.com/article/extensorretinaculumofhand (Accessed: 7 January 2026).
