Occur in two locations: the body of the hamate and the hook (hamular process) of the hamate
Fractures are present in 2 to 4% of carpal bone fractures
Body fractures are less common and are associated with dislocation of the fourth and fifth metacarpals
Axial force transmitted down the metacarpal shaft (a fall or fist strike)
Hook fractures occur from a direct force from an object strikes the palm such as that from a bat, golf club or racket
Have increased suspicion in these athletes who present w/ ulnar sided wrist pain
Diagnosis is frequently missed; chronic fractures are associated w/ flexor tendon rupture and ulnar neuropathy
PE: Tenderness localized over the hamate (in the hypothenar eminence) and over the dorsal ulnar aspect of the wrist. Swelling may be present. Look for resisted flexion of the 5th digit when the wrist is held in ulnar deviation. May note sensory changes in ulnar nerve distribution
Imaging: PA and lateral views of the wrist will show a body fracture but will frequently MISS a fracture of the hook of the hamate. In those with a clinical suspicion for this entity, order a “carpal tunnel view.” In the proper clinical setting, CT imaging is excellent for those with high suspicion and normal plain films.
