Efficacy of longitudinal computed tomography for scaphoid fracture. A new posture

We developed a new method for taking reproducible and accurate longitudinal computed tomography of the scaphoid (Δ hand CT). The patient makes an equilateral triangle with bilateral thumbs in radial abduction with the index fingers. The patient lies prone in the CT scanner with both hands on the midline above the head, ensuring that the axis of the thumbs is perpendicular to the body axis. Twelve patients with scaphoid fracture were evaluated utilizing the Δ hand CT. In eight patients, Δ hand CT was performed before treatment. We compared findings with those of plain radiograms. Target sign indicating accurate longitudinal scan of the scaphoid were obtained in sixteen of seventeen contralateral (normal) scaphoid on Δ hand CT without any position adjustment after scouting. Humpback deformity was observed in seven of eight fractured scaphoid on Δ hand CT performed before treatment. However, in just one case of the eight on plain radiograms, was deformity noted. The bony continuity between proximal and distal fragments was observed in five out of twelve scaphoid on Δ hand CTs, even though fracture lines were clearly seen on the plain radiograms. Thus, the Δ hand CT method has been shown to be highly reproducible and at an early stage provides good information regarding minimal displacement, deformity and bone union before such are detectable on plain radiograms. (author)