Fig. 3

The application of electromagnetic navigation in multiple procedures. a, b Guide wire insertion. In the navigation system, the procedure and track of the Access Tracker were visible in all spatial planes in real time so the operator could make quick adjustment if needed. c After the uniportal endoscope was placed, the endoscopic anatomical structures such as S1 superior facet joint, L5 inferior facet joint tip, and isthmus could be recognized by Access Tracker in the navigation system. It also could assist with recognizing the location of the intervertebral disc for severe intervertebral collapse. d The Access Tracker evaluated the depth of processed intervertebral space