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real-time feedback they receive from the computer, they're able to place cutting guides at exact angles in order to make precise cuts. Potential drawbacks of image-guided procedures include the increased costs of getting CT or MRI images before surgery. Physicians and facilities may not want to spend the extra money for pre-op imaging — $500 to $1,000 per procedure — which leads me to believe imageless systems will grow in popularity.
• Imageless surgery doesn't require pre-op images. Surgeons instead create digitized models of the patient's anatomy using tracking probes attached to infrared trackers. As surgeons place the trackers at key landmarks of the joint, the computer essentially learns the patient's anatomy to provide surgeons with the best surgical approach.
During image-guided and imageless surgery, surgeons use touchscreen controls or a foot pedal to toggle through menu options and input data the computer needs. The system's monitor is typically housed on a boom, which connects to a computer cart. Handheld burrs or saws are linked to the computer through cords and cables. An infrared camera hung on a support next to the OR table captures information received by the tracking pins and sends the data to the computer through a hardwired cable.
Surgeons must still make manual cuts. It's a process associated with inevitable human error, resulting in slight deviations from intended cuts. They might feel compelled to chase the perfect path mapped out by the computer, spending extra time altering cuts by a degree or two.
Time to learn
Placing the tracking pins and registering the patient's data can be done in about 10 minutes, but the subtleties of cutting with computer assistance take time to master and can extend initial case times by 25 to 50%. Surgeons will get close to time-neutral or perhaps even save time as they become proficient with the technology. They'll eventually appreciate the accuracy of
