Hook of hamate fracture
Classic history and presentation: Typical history includes either a direct blow to the hook of the hamate or repetitive microtrauma from gripping activities in athletes. This may also present as a chronic injury.
Prevalence: Hook of hamate fractures account for approximately 2%-4% of carpal fractures.
Risk factors: Recent trauma or participation in sports requiring gripping a racket or bat.
Pathophysiology: This fracture can be caused by a direct blow to the hypothenar eminence, repetitive microtrauma from gripping bats or rackets in athletes, or indirect shearing force from extrinsic flexor tendons of the ring and small fingers.
Grade / classification system: Hook of hamate fractures can be classified according to the anatomic location within the hook: base, waist, or avulsion, although this classification does not typically determine treatment or prognosis.
S62.156A – Nondisplaced fracture of hook process of hamate [unciform] bone, unspecified wrist, initial encounter for closed fracture
208369005 – Closed fracture hamate, hook
Differential Diagnosis & Pitfalls
- Triangular fibrocartilage complex (TFCC) tear
- Flexor carpi ulnaris (FCU) tendinopathy
- Scaphoid fracture
- Lunate dislocation (perilunate dislocation)
- Ulnar tunnel syndrome
- Cubital tunnel syndrome
- Snapping extensor carpi ulnaris (ECU)
- Vaughan-Jackson syndrome
- Ulnar styloid impaction syndrome
- Ulnocarpal abutment syndrome