Triquetrum Bone

Key Features & Anatomical Relations

The triquetrum bone is one of the eight carpal bones of the hand. It’s pyramid-shaped and is found in the proximal row of carpal bones. It’s classified as a short bone and includes the following bony features:

- surfaces: palmar and dorsal surfaces;

- landmarks: lunate, hamate, and pisiform articular facets.

More information regarding these bony features can be found in the Surfaces and Landmarks tabs for this bone.

The triquetrum bone is located:

- proximal to the hamate bone;

- distal to the ulna;

- posterior to the pisiform bone;

- medial to the lunate bone.

It articulates with the:

- lunate bone at the lunotriquetral joint;

- hamate bone at the triquetrohamate joint;

- pisiform bone at the pisotriquetral joint.

Ossification

Ossification of the triquetrum bone occurs at one ossification center, which appears within the third year (Standring, 2016). Complete ossification occurs during early adolescence.

Variations

In some individuals:

- carpal fusion, or coalition, between the triquetrum and lunate bones may be present, forming the os lunotriquetrum;

- the triquetrum bone may be present in a bipartite condition (i.e., divided into two parts);

- an accessory bone, known the os triangulare, may be present between the ulna, lunate and triquetrum bones (Tubbs, Shoja and Loukas, 2016).

Surface Anatomy

With regard to surface anatomy, the triquetrum bone can be palpated on the medial aspect of the wrist during abduction of the wrist joint.

List of Clinical Correlates

- Fracture of triquetrum bone

References

Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series 41st edn.: Elsevier Limited.

Tubbs, R. S., Shoja, M. M. and Loukas, M. (2016) Bergman's Comprehensive Encyclopedia of Human Anatomic Variation. Wiley.