Figure 1

(A) Placement of one C-arm fluoroscope, and (B) Placement of two C-arm fluoroscopes. The AP fluoroscope (I) (GE/OEC 9800, Salt Lake City, UT, USA), was positioned vertically with the C-arm's pivot maintained at 45° or less to the long axis of the operation table. The C-arm of the lateral fluoroscope (II) (GE/OEC 7700, Salt Lake City, UT, USA) was placed under the operation table horizontally while it was tilted away from the C-arm of the AP fluoroscope to prevent collision.