ABSTRACT
Flexor tendons are surrounded, for a good part, by a synovial sheath in which they glide. This sheath is made of two separate layers, an internal one iii (or visceral), and an external one (or parietal), which unite in a cul-de-sac at both extremities. The cavity between these two layers contains, under normal circumstances, a small quantity of synovial fluid produced by the cells of the internal layer.
