Tendon Sheath of Abductor Pollicis Longus and Extensor Pollicis Brevis
Vagina tendinum abductoris longi et extensoris brevis pollicis
Read moreAnatomical Relations
The tendon sheath of the abductor pollicis longus shares a synovial tendinous sheath with the extensor pollicis brevis. These two tendons pass deep to the extensor retinaculum in a single compartment, lateral to the styloid process of the radius. They continue as far as the proximal bases of the metacarpals.
Related parts of the anatomy
Structure
The tendon sheath of the abductor pollicis longus and extensor pollicis brevis muscles has an outer fibrous component and an inner double layered sheath of synovial membrane that is akin to a longitudinal bursa. The synovial layer is composed of an inner visceral layer and an outer parietal layer. The synovium produces a thin layer of lubricating fluid between the visceral and parietal layers which surround the tendons.
Function
The tendon sheath of the abductor pollicis longus and extensor pollicis brevis muscles provides a well-lubricated, smooth surface that reduces friction during movement of the tendon.
List of Clinical Correlates
—Tendovaginitis
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Tendon Sheath
Tenosynovectomy refers to the excision of thickened tendon sheath and other tissue surrounding a tendon, commonly seen in infection, chemical irritation, and rheumatoid arthritis (synovectomy).
