Case 3

A 25 year old male presents to the emergency department complaining of pain on movement of his thumb. He was struck on the tip of his thumb by a basketball during a game. He has normal sensation and capillary refill distally. There is very limited range of motion of his first carpometacarpal joint and marked tenderness at the base of his first metacarpal. His radiograph is shown below.

IDevice Question Icon Question
What is the most likely diagnosis?
  
Avascular necrosis of the scaphoid
Carpo-metacarpal dislocation
Trapezoid fracture
Trapezium fracture
Triquetrum fracture