Carpal tunnel

Last revised by Assoc Prof Craig Hacking on 07 Sep 2021

The carpal tunnel is a fibro-osseous canal in the anterior (volar) wrist that acts as a passageway for structures between the anterior forearm and the hand.

The carpal tunnel contains the following structures, from superficial to deep:

Note, the flexor carpi radialis is often wrongly stated to be within the carpal tunnel. Its course is in fact between the superficial and deep layers of the flexor retinaculum itself within its own compartment.

The tendons within the carpal tunnel are surrounded by synovial sheaths: one which envelops the flexor digitorum superficialis and profundus together, and a separate sheath for the flexor pollicis longus.

Onto the surface of the medial aspect is formed the Guyon's canal through which runs the ulnar nerve and artery (ulnar nerve more medial), superficial to the tunnel. More laterally, the palmaris longus is attached to the superficial surface. The palmar cutaneous branch of the median nerve runs superficial. 

Variant anatomical structures within the carpal tunnel 2:

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Cases and figures

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  • Figure 4: Gray's illustration
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