How to Ensure Navigation Integrity Using Robotics in Spine Surgery
During many cadaver labs under robotic guidance, researchers have discovered a few steps to help ensure navigation integrity throughout the procedure. The surgeon must securely attach the patient reference to the patient. An easy way to become inaccurate is to disturb the patient reference. This can happen without awareness and could be critical if it occurs after the initial landmark check. Continued accuracy of the system throughout the procedure is not guaranteed. For this reason, the navigation system should continuously monitor the patient reference to ensure that it has not been disturbed. Good navigation techniques are also important, including new reflective spheres for every case and verification that the spheres are pressed fully onto the posts. One should position all arrays to face the camera while avoiding steep angles and interference from other instruments in the field. One issue common to robotic guidance for pedicle screw placement is skiving. Even when a rigid robot arm is used, the patient can move when trajectories have a steep entry point. In this situation, care must be taken when the entry hole is created to allow the drill to do the work. With an accurate entry hole, the rigid robotic arm will hold instruments at the correct trajectory. A final suggestion for ensuring navigation integrity is to leverage surgeon experience. Ensure that the trajectory of the robot looks correct with respect to the patient's anatomy, and make sure the tactile feel is consistent with the navigation feedback.
Use of navigation in spine surgery offers many benefits, but adoption has been very limited. Robotic guidance is reducing the steep learning curve associated with surgical navigation, and by following a few key steps, the surgeon can maintain confidence throughout the surgical procedure.