The hamate is one of the many carpal bones in the wrist. It sits in the distal row on the far ulnar side and articulates with the fourth and fifth metacarpals, capitate, and triquetrum. The proximal surface has a convex shape to allow for articulation with the proximal carpals. The hamate also has a hook that projects outward. This hook makes up a part of Guyon's canal. Guyon's canal is formed by the hamate, pisiform, and the connecting ligament. The ulnar nerve and ulnar artery run through it. The ulnar nerve begins at the side of the neck and ends in the pinky finger and ring finger. Of all carpal fractures, 5 percent of those occur on the hamate bone. The most common location of hamate fractures is at the hook. Since Guyon's canal houses both the ulnar artery and the ulnar nerve, fractures here put both at risk. The hook can break off and put pressure on the ulnar nerve.
Written and medically reviewed by the Healthline Editorial Team
In Depth: Hamate