This patient is presenting with a perilunate dislocation with carpal tunnel symptoms. The most important next step in treatment is reduction of the dislocation. Kozin et al note that these injuries can be overlooked and have variable propagation patterns through the carpus/carpal ligaments. This patient has a radial styloid fracture due to avulsion of the radiocarpal ligaments. Melone et al note that these injuries were historically treated with closed reduction and pinning, but more recently the trend is for open reduction and fixation, for optimal anatomic restoration.
Melone CP Jr, Murphy MS, Raskin KB: Perilunate injuries: Repair by dual dorsal and volar approaches. Hand Clin 2000;16:439-448
PMID:10955217 (Link to Abstract)
Kozin SH: Perilunate injuries: Diagnosis and treatment. J Am Acad Orthop Surg 1998;6:114-120
PMID:9682074 (Link to Abstract)