| 摘要 |
The instrumentation is used by orthopaedic surgeons for accurate and rapid placement of distal locking screws in intramedullary nails. A probe inserted into the intramedullary nail positions two electromagnetic drive coils with their magnetic axes parallel to and at a fixed offset from the axis of a transverse hole to be drilled. The drive coils generate alternating magnetic fields over intermittent and non-overlapping time intervals in a manner that provides independent sources of positional information. A hand-held guide, containing a drill bushing and four receiving coils with the same offset as the drive coils, when moved about in the vicinity of the probe, produces a corresponding movement of graphical images on a display screen. The graphical images provide intuitive information as to how the guide must be moved to accurately align the drill bushing with the axis of the transverse hole. With the aid of continuous visual information on the display screen, the surgeon holds the guide and bushing in proper position while making a stab incision to the bone, while drilling or driving a trocar through the near and far cortices of the bone, and while inserting and fastening the locking screw. The intrumentation enables distal targeting by surgeons without specialized training or experience and eliminates the need for C-arm x-ray machines that increase operating room costs and increase the risk of radiation exposure to the patient and the surgeon. |
