Anatomical Relations
The common flexor tendon sheaths envelop the flexor tendons of the digits. There are two separate sheaths for the flexor digitorum superficialis and the flexor digitorum profundus. On occasion, the two sheaths are in communication with each other deep to the flexor retinaculum (Standring, 2016).
The proximal origin of the common flexor sheaths is 2.5 cm proximal to the flexor retinaculum and extends as far as the mid metacarpals. They are blind ended sacs; however, the sheath for the fifth digit is prolonged.
Related parts of the anatomy
Structure
The common flexor sheath 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 common flexor sheath provides a well-lubricated, smooth surface that reduces friction during movements of the tendons.
List of Clinical Correlates
—Tendovaginitis
References
Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series 41st edn.: Elsevier Limited.
Learn more about this topic from other Elsevier products
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).
