Occult fractures of the scaphoid: the role of ultrasonography in the emergency department.

OBJECTIVE: To evaluate ultrasonography (US) performed by an emergency radiologist in patients with clinical suspicion of scaphoid fracture and normal radiographs.
MATERIALS AND METHODS: Sixty-two consecutive adult patients admitted to our emergency department with clinical suspicion of scaphoid fracture and normal radiographs underwent US examination of the scaphoid prior to wrist computed tomography (CT), within 3 days following wrist trauma. US examination was performed by a board-certified emergency radiologist, non-specialized in musculoskeletal imaging, using the linear probe (5-13 MHz) of the standard sonographic equipment of the emergency department. The radiologist evaluate for the presence of a cortical interruption of the scaphoid along with a radio-carpal or scapho-trapezium-trapezoid effusion. A CT of the wrist (reference standard) was performed in every patient, immediately after ultrasonography. Fractures were classified into two groups according to their potential for complication: group 1 (high potential, proximal or waist), group 2 (low-potential, distal or tubercle).
RESULTS: A scaphoid fracture was demonstrated by CT in 13 (21%) patients: eight (62%) of them belonged to group 1 (three in the proximal pole, five in the waist), five (38%) to group 2 (three in the distal part, two in the tubercle). US was 92% sensitive (12/13) in demonstrating a scaphoid fracture. It was 100% sensitive (8/8) in demonstrating a fracture with a high potential of complication (group 1).
CONCLUSIONS: Our data show that, in emergency settings, US can be used for the triage to CT in patients with clinical suspicion of scaphoid fracture and normal radiographs.