Universal calibration of surgical instruments for spinal stereotaxy

PURPOSE: To describe new software applications and interchangeable instrume ntation enabling the use of standard surgical instruments with image-guided systems for stereotactic spinal procedures. CONCEPT: The ability to adapt essentially any surgical instrument for stere otactic procedures will improve the safety and accuracy of image-guided spi nal surgery. RATIONALE: Using universal dynamic registration hardware and software, stan dard surgical instruments are adapted for real-time image-guided surgery, T he Radionics Optical Tracking System (Radionics, Inc., Burlington, MA) has custom software applications and universal hardware adaptation devices for spinal stereotaxy that allows the use of standard instruments for intraoper ative guidance. An array of light-emitting diodes can be attached to essent ially any rigid instrument with a definable tip and can then be calibrated to the system for intraoperative use. Stereotactic guidance of a drill, tap , and screwdriver may improve screw placement accuracy in spinal surgery be cause every step of the procedure can be monitored in real time. DISCUSSION: Most stereotactic systems have only a standard probe or limited instruments for localization, targeting, and tracking a procedure. The sur geon then resumes the operation using standard surgical instruments without the benefit of image guidance for the key steps of the procedure. Because each surgical step for screw placement in the spine has a potential for err or, use of multiple instruments that can be interchanged for real-time imag e-guided spinal surgery may increase the accuracy and safety of spinal inst rumentation procedures. These techniques can also be applied to intracrania l image-guided surgery.