BACKGROUND
Closed reduction and internal fixation of upper limb fractures is usually performed under image intensifier guidance. Accurate reduction can only be confirmed by obtaining images in two perpendicular planes. The surgeon may change the position of either the C-arm or the limb in order to acquire images in both ‘AP’ and ‘lateral’ planes. Moving the limb risks fracture displacement if the injury is unstable. Conversely, repositioning the C-arm is time consuming, particularly if the radiographer is unfamiliar with the procedure. With both techniques, minor position adjustments and repeated screening is usually necessary to obtain accurate ‘AP’ and ‘lateral’ images rather than oblique views.
TECHNIQUE
We use two image intensifiers to obtain simultaneous ‘AP’ and ‘lateral’ images of the upper limb. The patient is positioned supine with the arm abducted. A standard C-arm is positioned at the head-end of the patient, and used to obtain AP images (Fig. 1). A mini C-arm is then brought in over the arm table to provide lateral radiographs.
Figure 1.
A conventional C-arm and a mini C-arm arranged together to provide simultaneous bi-planar images of the upper limb.
DISCUSSION
A conventional C-arm and a mini C-arm may be arranged together to obtain biplanar images of the upper limb simultaneously, whilst providing the surgeon with sufficient room to work. This technique allows the surgeon to obtain the simultaneous true ‘AP’ and ‘lateral’ images reliably without repeated position adjustments. Such an arrangement is particularly useful for closed reduction and k-wire fixation of supracondylar fractures of the humerus in children. The procedure is quicker, and both the patient and the surgical team are exposed to less radiation.