Review Question - QID 213073

A displaced intra-articular fracture with a fragment containing the critical volar-ulnar corner rim of the distal radius would result in volar translation of the carpus.

Distal radius fractures are one of the most common orthopedic injuries and can result from low-energy trauma in older and osteoporotic patients or high-energy trauma in young patients. Intra-articular involvement poses treatment challenges for these fractures as the fragments are crucial to articular stability and are difficult to achieve fixation with traditional distal radius plates. Fractures with intra-articular comminution of the distal radius that involve either the dorsal or volar rim of the lunate fossa, which can destabilize the radiocarpal joint, can lead to volar or ulnar translation of the carpus.

Orbay et al. performed a retrospective review of patients undergoing either hook plate fixation or volar opening wedge osteotomy for volar marginal fragment distal radius fractures. For the patients treated with hook extension plates, there was a 90% success rate in the prevention of volar subluxation of the carpus. For patients that required volar open wedge osteotomy to redistribute joint loading forces in those that developed avascular necrosis of the volar marginal fragments, all patients had improved pain, function, and radiographic concentric reduction of the radiocarpal joint. They concluded that hook plate fixation provides an effective means of fixation of a volar marginal fracture of the distal radius with volar opening wedge osteotomy as an effective salvage procedure.

O'Shaughnessy et al. performed a retrospective study of hook plate fixation of distal radius fractures with volar marginal rim fragments. There were no patients in the study that lost fixation of the volar marginal fragments after treatment with hook plates with the most common complication being symptomatic hardware requiring removal of both the traditional plate and the hook plate. The authors concluded that hook plate fixation provides a highly effective means of distal radial fragment fixation that is not amenable to traditional plate fixation.

Illustration A depicts a lateral radiograph of the right wrist with a fracture of the volar-ulnar corner resulting in volar translation of the carpus. Illustration B depicts a lateral radiograph of the wrist with a ulnar hook plate buttressing an articular surface rim fracture.

Incorrect answers:
Answer 1: Impaction fractures of the lunate fossa do not result in translational instability of the carpus.
Answer 3: A radial styloid fracture can result in ulnar translation of the carpus if the fragment is large enough to involve the large radiocarpal stabilizing ligaments.
Answer 4: An extra-articular fracture of the distal radius with apex volar angulation may have dorsal comminution, but there is no added risk of volar carpal translation.
Answer 5: An extra-articular distal radius fracture with apex dorsal angulation leads to volar tilting of the articular surface, but there is no volar translation of the carpus.