A
An extra-articular fracture of the distal radius with volar apex angulation.
B
An intra-articular fracture isolated to the radial styloid process.
C
A dorsal fracture-dislocation of the radiocarpal joint.
D
An intra-articular fracture of the distal radius with volar subluxation of the carpus.
Explanation:The correct option is 'd'. A Barton's fracture is a shear-type, intra-articular fracture of the distal radius combined with a subluxation or dislocation of the carpus. A volar Barton's fracture involves the volar rim of the radius with volar displacement of the carpus along with the fracture fragment. Option A describes a Smith's fracture, and Option B describes a Chauffeur's (Hutchinson) fracture.
Reference: Jupiter JB. Fractures of the distal end of the radius. J Bone Joint Surg Am. 1991;73(3):461-469.