Nine extrinsic flexor tendons pass through the carpal tunnel. They are: the flexor pollicis longus, the flexor digitorum superficialis and profundus.
Any increase in the size of the structures within the carpal tunnel, or decrease in the volume of the carpal tunnel can cause pressure on the median nerve and lead to the symptoms of Carpal Tunnel Syndrome (CTS).
For many years, transecting the transverse carpal ligament, called an open carpal tunnel release (OCTR), has been accepted as a surgical treatment for patients with carpal tunnel syndrome.
The palmar carpal ligament is the superficial part of the flexor retinaculum. It is attached medially and laterally to the styloid processes of the ulna and radius, and blends with the flexor retinaculum. The ulnar nerve emerges from beneath this fascia, entering the hand superficial to the flexor retinaculum.
On the posterior surface of the hand is the extensor retinaculum, a strong fibrous band under which lie the extensor tendons.
