Hook of hamate bone

The hook of hamate (Latin: hamulus) is found at the proximal, ulnar side of the hamate bone.

The hook is a curved, hook-like process that projects 1–2 mm distally and radially.

The ulnar nerve hooks around the hook of hamate as it crosses towards the medial side of hand.

The hook forms the ulnar border of the carpal tunnel, and the radial border for Guyon's canal.

Numerous structures attach to it, including ligaments from the pisiform, the transverse carpal ligament, and the tendon of Flexor carpi ulnaris.

Its medial surface to the flexor digiti minimi brevis and opponens digiti minimi; its lateral side is grooved for the passage of the flexor tendons into the palm of the hand.