Computer-based navigation in the Operating Room
What does computer-based navigation in the operating theatre mean?
During surgery, surgical instruments are virtually displayed into the C-arm or CT images of the patient, similarly to a map in a GPS device. The navigation allows a safe and exact positioning of the surgical instruments any time during surgery.
Illustration: Example of computer-navigated surgery. The instrument (green) is projected online into the CT images of the patient. The placement can be checked and corrected if necessary. The pedicle screw (red) is placed transpedicularly close to the spinal canal.
What are the advantages of the computer-based navigation?
The computer-based navigation allows a more precise handling and positioning of the instruments. Even if the surgeon does not see the instrument in the patient's body, the position of the instrument is correctly displayed in the monitor.
Hence, computer-based navigation allows a considerable increase of safety during surgery, where one-tenth of a millimetre determines success or failure. Furthermore, the computer based navigation allows highly precise surgical minimally invasive interventions as a full dissection of the operated structures is not necessary.
Every step of the operation is transmitted in real time mode, which leads to a significant reduction of interruptions due to instrument control by x-ray. Thus, the exposure to radiation and even the operation time can be reduced.
How does the computer-based navigation work?
Two IR cameras and a powerful computer are fundamental to the navigation system. Marker points on the instruments and the patient enable the system to locate the surgical instruments and the patient in the three-dimensional space.
C-arm or CT images taken before or during surgery are compared and aligned to the actual position of the patient. Thus, the instruments can be displayed on the C-arm or CT images. As the navigational system works on the base of IR light, there is no additional exposure of x-rays or magnetic field.
Which technology do the surgeons currently use in the trauma clinic Frankfurt am Main?
The surgeons exclusively use a navigation system of BrainLab/Munich. BrainLab is one of the leading enterprises in the sector of computer-based surgery. It is due to its high quality products that BrainLab has been certified by the Arbeitsgemeinschaft für Osteosynthesefragen (AO), a global network in the sector of surgical orthopedics.
The navigation system can be combined with an intra-operative three-dimensional Siemens x-ray examination device (Orbic IsoC-3D) or an intra-operative CT.
Does the computer navigation cause any injury?
No. The systems works on an IR base, without x-ray, the marker points do not leave stains and are removed immediately after surgery. Computer navigation provides additional information and assistance for the surgeon, but it will never replace the surgeon.
What will happen in case of system malfunction?
BrainLab Systems meet highest quality requirements, they hardly ever crash. During the whole surgery the surgeon checks if the data are reasonable, any misrepresentation on the monitor can be corrected if necessary. In case of doubt every surgeon in the trauma clinic is able to continue operating without computer-based navigation.
For which kind of surgery computer-based navigation is appropriate?
Computer-based navigation allows highly precise display and control of instruments in hidden parts of the body. One of our standard operations is the spinal stabilization with screws, which are placed transpedicularly from behind into the vertebral body.
The pedicles, sometimes not thicker than 3 or 4 mm, limit the spinal canal with the therein-located spinal cord. Thus, the use of the computer-based navigation tool provides more safety in placing the screws.
Computer-based navigation can also be used to stabilize pelvis fractures or determine the amount of bone excision while operating on bony tumors in the pelvis area.