Hamate

The hamate is one of the eight carpal bones of the wrist, located in the distal row. It is sometimes referred to as the hamatum or os hamatum, and it features a distinctive hook-like projection on its palmar (anterior) surface, known as the hook of hamate (hamulus).

Anatomy and articulations: The hamate articulates proximally with the capitate, and it forms part of the articular complex that links the distal carpal row to the bases of the fourth and fifth metacarpals. It also articulates with neighboring carpal bones such as the trapezoid. The hook of hamate projects anteriorly and serves as an important anatomical landmark on the ulnar side of the wrist.

Relations and function: The hook of hamate forms part of the boundary of Guyon’s canal, through which the ulnar nerve and ulnar artery pass; this makes the area clinically relevant in cases of nerve irritation or compression. The hamate also serves as an attachment site for ligaments and contributes to the pulley system for flexor tendons, particularly those of the ring and little fingers, aiding efficient finger flexion.

Clinical significance: Fractures of the hook of the hamate are common in sports and falls, sometimes occurring without visible fracture lines on standard wrist X-rays. Oblique or specialized imaging, CT, or MRI may be required for diagnosis. Hook fractures can threaten the ulnar nerve or artery, and nonunion is a potential complication. Treatment ranges from immobilization for non-displaced fractures to surgical excision or fixation of the hook in cases of displacement, nonunion, or symptomatic ulnar neuropathy.

Etymology: The name derives from Latin hamatus, meaning hooked.