A
Involvement of the medial malleolus
B
Disruption of the syndesmosis
C
Subluxation of the talus
D
Significant involvement of the distal tibial weight-bearing articular surface (plafond)
Explanation:The correct option is 'd'. A pilon (or plafond) fracture is distinguished by extensive involvement of the weight-bearing articular surface of the distal tibia, typically resulting from high-energy axial loading. Unlike rotational ankle fractures (which primarily involve malleoli), pilon fractures involve metaphyseal comminution and impaction of the articular cartilage.
Reference: Ruedi TP, Allgower M. The operative treatment of intra-articular fractures of the lower end of the tibia. Clin Orthop Relat Res. 1979;(138):105-110.