Occult fractures of the carpals and metacarpals: demonstration by CT

Occult fractures of the carpals and metacarpals occur frequently and are associated with major disability. The cross-sectional display and superior resolution of CT are well suited to the demonstration of these fractures. Sixteen patients with pain and negative conventional radiographs were chosen for further evaluation by CT. Imaging was performed in two planes and showed 21 fractures. The transaxial plane was the most revealing imaging plane. Coronal imaging was equal or superior to the transaxial plane in most fractures of the scaphoid, lunate, capitate, and pisiform bones and of the bases of the metacarpal bones. The direct sagittal plane was the best imaging plane in one patient with fractures of the scaphoid and lunate bones. After discovery of the fracture on CT, surgical removal of the avulsed fracture fragment was recommended in seven patients and fusion was recommended in three. Eight patients had a marked decrease in pain after the surgical procedure. The accuracy of CT for the demonstration of occult fractures may result in earlier recognition of these fractures and a reduction in the associated disability.