Pisiform

Original Editor - Nina Myburg

Top Contributors - Nina Myburg, Kim Jackson, Nikhil Benhur Abburi, Wendy Snyders and Leana Louw

Description[edit | edit source]

Pisiform bone (Left Hand)

The pisiform is one of eight carpal bones that forms part of the wrist joint. The name pisiform is derived from the Latin word pisum which means "pea". It can be felt on the anteromedial side of the wrist.  It is considered a sesamoid bone but contributes to wrist stability[1]. The pisiform can be found in the proximal row of carpal bones[2].

Structure[edit | edit source]

It is the smallest carpal bone and is a pea-shaped bone[3][2] embedded in the flexor carpi ulnaris tendon[4]. Its dorsal surface is smooth and has an oval facet while the volar surface is rough and rounded[5]. The lateral surface is rough and concave and the medial surface is convex and rough[5].

Function[edit | edit source]

The pisiform serves as an attachment for tendons and ligaments[3]. The flexor carpi ulnaris covers the volar surface and the other connections onto the pisiform include the pisohamate ligament, extensor retinaculum, origin of the abductor digiti minimi, pisometacarpal ligament and anterior annular ligament[1].

The pisiform also forms part of the ulnar canal or Guyon canal[6]. The Guyon canal is a fibro-osseous tunnel of which the pisiform forms part of the ulnar border[6]. The ulnar nerve and ulnar artery pass through this canal[6].

It also acts as a pulley for the flexor carpi ulnaris tendon[4].

Articulations[edit | edit source]

The pisiform only articulates with the triquetrum[2][4] and does not form part of the wrist joint[4].

Muscle attachments[edit | edit source]

  • Flexor carpi ulnaris – This is an extrinsic muscle that attaches to the pisiform, hook of hamate and 5th metacarpal. It allows wrist flexion and adduction.
  • Abductor digiti minimi – This is a hypothenar muscle. It allows abduction of the 5th finger and flexion of its proximal phalanx.

See Also[edit | edit source]

Pisiform bone animation
Pisiform bone (left wrist) animation


References[edit | edit source]

  1. 1.0 1.1 Petrou IG, Savioz-Leissing C, Gray A. Traumatic dislocation of the pisiform bone. Journal of Hand and Microsurgery. 2018 Apr;10(01):037-40.
  2. 2.0 2.1 2.2 Wadsworth CT. Clinical anatomy and mechanics of the wrist and hand. Journal of Orthopaedic & Sports Physical Therapy. 1983 Apr 1;4(4):206-16.
  3. 3.0 3.1 Tang A. Varacallo M. Anatomy, Shoulder and Upper Limb, Hand Carpal Bones. StatPearls - NCBI Bookshelf. 2018
  4. 4.0 4.1 4.2 4.3 1. Stewart S. Pisiform Bone [Internet]. Kenhub; 2022 [cited 2023 Jul 26]. Available from: https://www.kenhub.com/en/library/anatomy/pisiform-bone
  5. 5.0 5.1 1. Micheau DrA, Hoa DrD. Pisiform bone - e-anatomy [Internet]. IMAIOS; 2023 [cited 2023 Jul 26]. Available from: https://www.imaios.com/en/e-anatomy/anatomical-structure/pisiform-bone-1537019620
  6. 6.0 6.1 6.2 Ramage JL, Varacallo M. Anatomy, Shoulder and Upper Limb, Hand Guyon Canal. StatPearls - NCBI Bookshelf. 2018