Attending neurosurgeon Swift Institute, United States
Introduction Augmented reality (AR) utilizes optical projections into the user’s field of view to create a visual overlay in the natural visual field. Augmedics Xvision recently received FDA approval for use in spine surgery for placement of pedicle screws. The Xvision system has proven to be accurate for placement of pedicle screws for which it is primarily used. However, the technology can be expanded to additional aspects of spine surgery such as tubular transforaminal interbody fusion (MIS TLIF).
Aims 1. To implement augmented reality technology to improve MIS-TLIF with real-time navigation via field of view navigation. 2. Develop methods to reduce radiation exposure during MIS-TLIF
Methods An intra-operative CT was performed and the data loaded into Xvision console for processing. The surgeon and assistant were fitted with Xvision head-mounted display (HMD). Percutaneous MIS pedicle screws were placed. Next, the contralateral facet is drilled out and graft material is placed utilizing AR display. The TLIF trajectory is planned using AR visualization and then a Jamshidi needle is placed along the trajectory. A guidewire is passed through the Jamshidi and then the Jamshidi removed. Dilators are placed over the guidewire before placing a 18 mm tubular retractor. The primary surgeon removed HMD to work under microscope while assistant continued the HMD for navigation. A transfacet approach to the disc space was performed using trajectory and guidance on the Xvision console. Navigated shavers were used to perform discectomy. After discectomy, planned intradiscal location of interbody was confirmed with Xvision navigation. An expandable interbody was malleted into disc space with traditional fluoroscopy. Rods and set screws were placed in standard fashion. Intra-operative CT or Xrays were used to confirm placement of interbody and accuracy of Xvision.
Results AR-MIS TLIF was performed on fifteen patients with twenty one total TLIF levels. All lumbar levels were successfully instrumented in this case series (1/2: 1, 2/3: 4, ¾: 3, 4/5:8, 5/1: 5). Accuracy for pedicle screw placement and TLIF trajectory was 100% as determined by fluoroscopy. Xvision Intra-discal navigation accuracy was confirmed via intra-operative fluoroscopy. There is a significant reduction (p < 0.01) in fluoroscopy time with AR-MIS TLIF when compared to traditional transfacet MIS-TLIF.
Conclusion This is the first report of utilizing augmented reality to perform an MIS-TLIF. Augmented reality allows for precision in establishing trajectory into the disc space as well as within the disc space to plan interbody placement. This allows for faster, more precise surgery with reducing radiation exposure.
