By Camilo A. Molina, MD, Washington University School of Medicine
Move over Superman, x-ray vision isn’t just for superheroes anymore. A growing number of surgeons using augmented reality (AR) surgical navigation are at the forefront of recent spine surgery innovation. We asked Dr. Camilo Molina, Assistant Professor of Neurosurgery and Orthopedic Surgery at Barnes-Jewish Hospital in St. Louis, MO and one of the pioneers behind Augmedics’ xvision spine system, to open our eyes to this futuristic-sounding technology. Here are the takeaways.
Augmented reality lets surgeons “see” through their patients’ skin and tissue. Augmented reality spine surgery allows surgeons to see patients’ anatomy as if we have “x-ray vision.” Similar to using GPS, we are then able to accurately and in real-time navigate instruments and implants during spine procedures. Unlike traditional navigation systems, AR allows us to do this while keeping our eyes directly on the patient, rather than looking over at a computer screen.
This novel AR technology is actually pretty simple. For something that sounds like it’s out of an episode of Star Trek, AR spine surgery is beautiful for its simplicity. We take a 3D intraoperative scan which is fed into an AR headset. A 3D visualization of the patient’s anatomy and 2D navigation data is then superimposed onto the surgical field, which we use to efficiently, accurately, and safely place spinal implants.
Augmented reality spine surgery is safe and highly accurate. In spine surgery, accuracy is critical. The spine is responsible for the uniquely human upright bipedal structure, but just as importantly, it safeguards the super conduction highway of nerves that allows our brains to communicate with our bodies. We often place implants with minimal room for error to avoid injuring these structures. This is particularly true in minimally invasive surgery, where we insert implants percutaneously, via small incisions in the skin.
We did a study back in 2020 to assess the accuracy and precision of percutaneous screw placement using AR navigation. The results, which were published in the Journal of Neurosurgery, found the overall clinical accuracy of AR navigated pedicle screw placement was 99.1%. Another study on AR navigated screw placement published in the Global Spine Journal earlier this year reported no adverse effects, no revisions, and no complications and further concluded that AR was a safe and accurate tool for spinal fixation. For spine surgeons, this level of safety and accuracy is paramount.
Augmented reality spine surgery eliminates surgeon attention shift and keeps focus directly on the patient. Let’s go back to the GPS example for a minute. Imagine driving a vehicle while using GPS. Would you want the GPS information superimposed on your windshield so you’re always looking at the road? Or would you prefer to constantly look away to your console or down at your phone? In surgery, we call this attention shift, and there’s a lot of data that shows that this kind of distraction negatively affects both cognitive and motor tasks. By using the AR headset, we eliminate it. The patient’s 3D anatomy and navigation data are superimposed directly onto the surgical field, so we are always looking directly at the patient.
Augmented reality navigation enables minimally invasive surgery (MIS). There’s a growing trend in spine surgery toward MIS procedures in recent years, and for good reason: the myriad of benefits include shorter hospital stays, faster recovery times, less blood loss, reduced postoperative narcotic use, lower infection rates, and cost savings, to name a few. In these percutaneous procedures we can’t physically see the anatomy, so we rely on technology to safely guide our instruments and implants through the correct trajectories. This is where surgical navigation comes in. And what we’re seeing with AR navigation specifically, is that the learning curve is so shallow, we’re actually empowering surgeons to make that jump to MIS.
Augmented reality spine surgery is already in use in ORs across the US, and it’s ready for primetime. Leonardo da Vinci said, “Simplicity is the ultimate sophistication.” AR navigation is so instinctive and easy to learn. For example, I’ve had residents who’ve never navigated before pick it up on the first try. We have a novel technology that enables surgical navigation to be easily and rapidly adopted; we know it’s safe, we know it works, and it’s actually more economically accessible than the alternatives. Xvision has been used to treat +2,000 patients in over 50 hospitals across the US and those numbers are climbing every day. The fact that AR navigation is being adopted is evidence that surgeons want to be on the cutting edge of surgical technique, they want to be advancing the field. They want to push that envelope of delivering a higher standard of care to their patients. Augmented reality navigation can do that. What the iPhone did for smartphone adoption, this will do for navigated spine surgery.
REFERENCES
1. Molina CA, Phillips FM, Colman MW, et al. A cadaveric precision and accuracy analysis of augmented reality-mediated percutaneous pedicle implant insertion [published online ahead of print, 2020 Oct 30]. J Neurosurg Spine. 2020;1-9. doi:10.3171/2020.6.SPINE20370
2. Bhatt FR, Orosz LD, Tewari A, et al. Augmented Reality-Assisted Spine Surgery: An Early Experience Demonstrating Safety and Accuracy with 218 Screws. Global Spine Journal. January 2022. doi:10.1177/21925682211069321
3. Léger É, Drouin S, Collins DL, Popa T, Kersten-Oertel M. Quantifying attention shifts in augmented reality image-guided neurosurgery. Healthc Technol Lett. 2017;4(5):188-192. Published 2017 Sep 18. doi:10.1049/htl.2017.0062
4. Phan K, Rao PJ, Mobbs RJ. Percutaneous versus open pedicle screw fixation for treatment of thoracolumbar fractures: Systematic review and meta-analysis of comparative studies. Clin Neurol Neurosurg. 2015;135:85-92. doi:10.1016/j.clineuro.2015.05.016
