What's the Diagnosis? By Dr. Michael Tom

A 24 yo M presents after a fall from a bike onto an outstretched hand. He is complaining of L wrist pain and swelling. His wrist xray is shown below. What's the diagnosis? (scroll down for answer)


Answer: Peri lunate dislocation (also note fracture of the ulnar styloid process)

  • Usually results from fall onto an outstretched/hyperextended hand or other high energy trauma
  • In a peri-lunate dislocation, the lunate has normal or near normal alignment with distal radius, while other carpal bones are dorsally displaced
  • In contrast to a lunate dislocation, in which the lunate has volar displacement (spilled teacup) and the remaining carpal bones have normal alignment
  • Up to 25% are missed at time of initial presentation
  • Surgical management indicated
  • Left untreated, patients are at risk for median nerve injury, avascular necrosis, and long term wrist dysfunction