Tendon sheath of extensor digitorum and extensor indicis
Vagina tendinum extensoris digitorum et extensoris indicis
- Latin synonym: Vagina tendinum musculorum extensoris digitorum et extensoris indicis
- Synonym: Tendinous sheath of extensor digitorum and extensor indicis muscles
- Related terms: Tendinous sheath of extensor digitorum and extensor indicis
Definition
The tendon sheath of extensor digitorum and extensor indicis is a common synovial sheath enclosing these tendons as they pass through the fourth dorsal compartment of the wrist, located beneath the extensor retinaculum and over the posterior surface of the radius.
The sheath extends from just proximal to the wrist joint to the level of the bases of the metacarpal bones, where the tendons diverge to reach the dorsal digital expansions on the fingers. It allows the tendons to glide smoothly during extension of the wrist and fingers, minimizing friction within the confined compartment.
The extensor retinaculum anchors to the radius and ulna via fibrous septa, dividing the dorsal wrist into six fibro-osseous compartments, each containing specific extensor tendons invested in their own synovial sheaths; the fourth compartment is the largest of these containing extensor digitorum and extensor indicis tendons.
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).
