Endoscope-Assisted Pedicle Screw Fixation using the Pedicle Guidance System

Kwon, Ji Woong; Jahng, Tae Ahn; Chung, Chun Kee; Kim, Hyun Jib; Kim, Daniel H

Abstract

OBJECTIVE
The aims of this study were to present the newly developed pedicle guidance system for minimally invasive pedicle screw fixation under endoscopic visualization and to evaluate the feasibility, safety, and efficacy of this device.
METHODS
The authors designed a special guidance device that allows a pedicle screw to be inserted with ease and accuracy under endoscopic visualization. The system consists of a bone biopsy needle (Jamshidi type needle), fiducial pins, a pushing trocar, retriever, specialized awls, and probes. After making an inch-long paramedian skin incision, the bone biopsy needle was percutaneously inserted into the pedicle, as in vertebroplasty, and the fiducial pin was inserted through the needle after removing the inner cannula. The fiducial pin was advanced into the vertebral body until the threaded distal end was positioned 1-2 cm away from the posterior bony structure. The biopsy needle was removed, leaving the fiducial pin in position. The operative wound was then dilated with a step dilator, a tubular retractor was introduced, and an endoscope was placed. Decompressive laminectomy and interbody fusion were then performed. A tubular retractor was repositioned in order to visualize the fiducial pins. A cannulated awl was used to create a hole over the fiducial pin. The pedicle trajectory was prepared using a cannulated probe, and a pedicle screw was inserted under fluoroscopic and endoscopic guidance. RESULT: Fifteen patients underwent surgery using this method. In all cases, the screws were safely inserted without misplacement. The overall operative time ranged from 180 min to 260 min (mean 219.3 min). There were no procedure related complications.
CONCLUSION
This newly designed device proved to be practical, time saving, and useful for endoscope-assisted pedicle screw fixation.