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.

Supracondylar fractures of the humerus: prediction of the cubitus varus deformity with CT.

Rotation of the distal fracture fragment in the supracondylar fracture is a contributing factor in the development of the cubitus varus deformity. Computed tomography (CT) is superior to conventional radiography in the assessment of the position of fracture fragments and was used to study 20 patients with supracondylar fractures after reduction. These fractures were followed up with radiography until healed. As determined from CT scans, rotation of the distal fracture fragment of greater than 10 degrees resulted in an abnormal Baumann angle and a cubitus varus deformity in all patients. Use of CT should facilitate the identification of this complication and thus treatment of these fractures and prevention of subsequent deformity.