Hamate hook fractures, also called “hook fractures,” is the most common hamate fracture, which frequently results when a handle sharply impacts the proximal hypothenar palm. This occurs most often in tennis, golf, and baseball. They may also result from a fall on an outstretched wrist and can be associated with more widespread injury.

The hook of the hamate is the point of attachment for hypothenar muscles. When it is fractured through the base, these muscles stress the fracture in different directions – creating an unfavorable environment for healing, producing high nonunion rates. Because the hook borders the Guyon canal, the ulnar artery and nerve – which travel through the canal – often sustain damage as well in this type of fracture.

Hamate hook fractures, much like scaphoid fractures, are not always evident on a standard X-ray. They are also vulnerable to complications, because of their predisposition to nonunion.

Hamate hook fractures require special radiographic imaging to confirm diagnosis and determine the extent of the damage.

These types of fractures are generally treated with excision of the hook fragment and smoothing of the base, in order to prevent future tendon chafing.