Guyon's canal

Guyon´s canal (canalis ulnaris) is found on the ulnar side of the hand distal to the canalis carpi.

Boundaries:

 * proximal: hiatus proximalis (opening in the lig. carpi palmare, approximately at the level of the proximal edge of the os pisiforme, through which the n. et vasa ulnaria from under the superficial fascia of the forearm to the subcutaneous tissue). The surface edge of the opening is reinforced in the so-called crus superficiale, the deeper edge borders the crus profundum;
 * distal: hiatus distalis (below the fibrous arch connecting the beginning of the m. flexor digiti minimi to the hamulus ossis hamati with the beginning m. abductor digiti minimi on the os pisiforme), in this opening they dive in r. profundus n. ulnaris and rr. profundi vasorum ulnarium into the deep, while r. superficialis n. ulnaris and rr. superficiales vasorum ulnarium run through this arch further distal to the IV. and V. finger;
 * ulnarly: os pisiforme, further distally also the beginnings of the hypotenar muscles;
 * radially: hamulus ossis hamati;
 * bottom: retinaculum musculorum flexorum (separates Guyon´s canal from the carpal tunnel), lig. pisohamatum et pisometacarpale;
 * ceiling: subcutaneous ligament, further distally m. palmaris brevis.

Content:

 * n. ulnaris et vasa ulnaria (so it goes through the Guyon canal above lig. carpi transversum – outside of the carpal canal).

Related articles

 * Topographical anatomy of the hand and fingers: foveola radialis, canalis carpi, Guiot space, Kanavel´s space
 * Syndroma canalis Guyoni