A Bosworth fracture is best described as which of the following?

• A. Rare fracture associated with SER fracture types
• B. Common distal radius fracture
• C. Talar dome fracture
• D. Calcaneal fracture

Answer: (A)

A Bosworth fracture is a rare fracture-dislocation of the distal radioulnar joint in which the distal ulna becomes entrapped behind the distal radius and cannot be reduced. This injury results from a supination-external rotation force, so it’s closely tied to SER-type injury patterns. That combination—rare occurrence plus the ulna getting locked behind the radius after a high-energy SER mechanism—is exactly what defines a Bosworth injury, making it the best description.

The other options describe injuries that don’t involve the forearm distal radioulnar joint in this locked dislocation pattern: a common distal radius fracture is much more typical and lacks the characteristic locked ulna; a talar dome fracture and a calcaneal fracture involve the ankle and heel bones, not the distal radioulnar joint.