Differential Diagnosis

  • Avulsion fracture at the ulnar collateral ligament attachment
  • Distal metacarpal fracture
  • Extensor tendon rupture
  • Metacarpophalangeal joint dislocation
  • Proximal phalanx fracture


The x-ray shows a small defect at the ulnar corner base of proximal phalanx. The correct diagnosis is an avulsion fracture at the ulnar collateral ligament attachment.


  • This injury is also known as skier’s thumb because of the frequency with which it’s associated with skiing accidents, in which the thumb is bent back by the ski pole

This injury is best identified on a good AP view of the thumb, and may not be visible in a standard hand x-ray exam

Pearls for Urgent Care Management and Considerations for Transfer

  • Initial treatment is aimed at reducing swelling and pain, and immobilization of the affected joint
  • Conservative treatment is possible for nondisplaced fractures
  • For displaced fractures, refer the patient for surgical consideration. Patients are most likely to require surgical repair if the ligament injury is complete or displaced, so prompt orthopedic consultation is recommended
A 45-Year-Old Man with Thumb Pain After a Fall
Share this !