Endoscopy-Assisted Diagnosis and Revision of a Malpositioned Screw.

Background: Pedicle screw insertion is a common procedure in spine surgery, and freehand, fluoroscopic, and robotic-assisted techniques all are used. These are indirect methods that use fluoroscopy, and direct visualization of canal involvement has not been possible. However, owing to the development of high-definition imaging modalities, delicate procedures that use endoscopy are possible.

Case Description: A 47-year-old man presented with severe radiating pain in his leg after undergoing L5-S1 level endoscopic transforaminal lumbar interbody fusion and percutaneous pedicular screw fixation. The patient then underwent an endoscopy-assisted technique for violated spinal canal and screw revision in which the misplaced screw was directly visualized using endoscopy and the trajectory of the misplaced screw was changed. With 30° endoscopy, we directly visualized the screw thread and root compression. Then with 0° endoscopy, we changed the screw trajectory inside the pedicle with an anatomic landmark. The patient's radiating pain was completely relieved after revision of the malpositioned screw. Postoperative imaging showed the revised screw trajectory inside the pedicle.

Conclusions: Endoscopy-assisted pedicle screw insertion does not require an additional incision, and early recovery after the procedure is possible. Accurate diagnosis of canal pathology and treatment are possible with direct visualization using endoscopy.