Contents

Name of bone

Trapezoid

Location/Articulation

The trapezoid bone (lesser multangular bone) is a carpal bone of the wrist, the smallest bone in the distal row. It has a wedge-shaped form, the broad end of the wedge constituting the dorsal surface and the narrow end, the palmar surface. The trapezoid bone also have four articular facets touching each other, separated by sharp edges.

The etymology derives from the Greek trapezion which means "irregular quadrilateral," from tra- "four" and peza "foot" or "edge." Literally, "a little table" from trapeza meaning "table" and -oeides "shaped."

Muscle and ligament attachments

Surface anatomy

  • The superior surface is quadrilateral, smooth, and slightly concave. It articulates with the scaphoid.
  • The inferior surface articulates with the proximal end of the second metacarpal bone.
  • The dorsalandpalmar surfaces are rough for the attachment of ligaments; the dorsal surface is the larger of the two.
  • The lateral surface, convex and smooth, articulates with the trapezium.
  • The medial surface is concave and smooth in the front for articulation with the capitate and rough in the back for the attachment of an interosseous ligament.




Figure 1. Surface anatomy of the left trapezoid bone

Radiography

Physical examination

Embryology

Anomalies

Injuries/Disorders 

Attachments:


trapezoid.png (image/png)