Trapezoid

Medically reviewed by Healthline Medical Team on April 20, 2015

The structure of the trapezoid bone forms a firm, stationary joint with the second metacarpal base. The trapezoid is shaped like a wedge. The side of the bone that is closest to the back of the hand, referred to as dorsal, is broader than the palm-side of the bone, described as palmar. It is the least frequently injured carpal bone. The structure of the trapezoid places it in a sheltered position. The trapezoid is two times wider dorsally than it is palmarly. It has been shown that the trapezoid lacks internal anastamoses, but has several sources of blood supply. Axial force, while applied to the second metacarpal base, can cause the trapezoid bone structure to become injured or even to fracture. People with trapezoid fractures tend to describe pain at the base of the second metacarpal. This may lead to wrist swelling and decreased range of motion. Standard treatment is not yet available as trapezoid fractures are a rare occurrence. However, sometimes a doctor will recommend the removal of a small fragment of trapezoid. In other cases, fractures of the trapezoid can involve open reduction and internal fixation.

CMS Id: 141503