SPECIAL EDITION: SURGICAL ROBOTS EXCELSIUSGPS® (MID-COURSE NOTES FROM USERS) (Orthopedics This Week)

Globus Medical, Inc.’s ExcelsiusGPS® and Medtronic’s Mazor X with StealthStation are the two most commonly purchased robotic assist platforms for spine and neurosurgeons in the United States.

Virtually every major spinal implant company (Zimmer Biomet, NuVasive, Inc., Stryker Corporation, JNJ Synthes and others) have or will soon announce their own spine surgery robot and, no doubt, hustle to catch up to the market leaders.

Neither Globus nor Medtronic releases robot unit sales numbers but two of Wall Street’s top medical device research departments (Wells Fargo Securities and Needham and Co.) estimate that between 140-200 Mazor X and ExcelsiusGPS systems have been sold so far in the United States.

The total available market is probably 2,000 units spread among 1,250 U.S. hospitals and clinics, so robotics have only penetrated about 8% of the market.

Last January 2018, we checked in with New York University Langone Orthopedic Hospital’s Chief of Spine Service for Education and Director of the Spine Fellowship Jeffrey Goldstein, M.D. about his new robotic system which, as it turned out, was Globus’s ExcelsiusGPS. Although he’d only used it in a couple cases and his colleagues were still coming up to speed, he was a happy customer as he explained to OTW:

“Robotic assist systems allow you to enter through smaller incisions with greater precision. I had a good level of confidence using fluoroscopy in minimally invasive surgery. With robotic assistance I have a higher level of confidence. And it’s faster.”

“I think the robotic assist system maintains my precision but with significantly less radiation exposure. Since its image guided, I can watch the screw being placed through the monitor and see that screw is going along the path I designed. I am more confident that the screw is precisely where I want it in the pedicle.”

But what happens after the post-purchase honeymoon period ends? What strengths or weaknesses do these systems reveal after extended day-to-day use?


The Neurosurgeon: Precision and Accuracy

This time, we checked in with both an orthopedic spine surgeon (Andrew Manista, M.D. at Capital Medical Center in Olympia, Washington) and a neurosurgeon (Scott Kutz, M.D. at Medical City Frisco in Dallas, Texas) each of whom had experience with BOTH the Mazor and ExcelsiusGPS systems.

Scott Kutz, M.D.

Scott Kutz, M.D. is a Plano, Texas-based neurosurgeon who’s specializes in percutaneous techniques, neuro navigation, artificial disc replacement and treating SI [sacroiliac] joint disorders. His Bachelor of Science degree is from the University of Illinois at Urbana-Champaign, his M.D. is from University of Illinois at Chicago, his surgical internship and neurosurgical residency was at Louisiana State University in New Orleans, and, finally his stereotactic and functional neurosurgery fellowship was at Rush in Chicago.

Dr. Kutz, who’s had Globus’ Excelsius GPS for more than year, told OTW that he’s very satisfied with the capabilities of his system and thinks it is a particularly robust platform for his purposes. He’d used both the Mazor Renaissance and the Mazor X in his clinic and actually waited a while before taking the plunge into a combination navigation and robotics platform. He settled on Globus’ Excelsius because, in his view, it had the most robust features—specifically, the way it married navigation to robotics.

“Robotics used to operate in isolation to navigation so that instruments were delivered precisely, but not necessarily accurately. Without the visual feedback that comes with navigation, it’s possible to find yourself somewhere you don’t want to be” he explained.

With the Excelsius, “I can see in three dimensions, which significantly reduces the risk of misplacement. I see in real time where I am. My revision rates using the navigation with robotics is exceedingly low—1% versus about 8-10%, which is the rate mentioned in the literature for free-hand pedicle screw placement.”

All complex systems have a learning curve. “I started by using Excelsius in the cadaver lab, and I had experience using both Mazor Renaissance and Mazor X in the operating room.”

“I chose Excelsius based on its integration of navigation with the robotic arm. The effect it has had on our practice is that it has helped us provide improved levels of care to our patients. I truly believe that we are in the golden age of spine surgery.”

“I’m seeing better clinical results. There’s certainly a learning curve and OR time is extended initially. But once you have a consistent workflow, you can reduce OR time. Patients are also attracted to practices that have robotics. It’s a great marketing tool.”

He also noted that the Excelsius platform can be used with pre-op CT scans or without a CT scan in those cases where either 2D fluoroscopic images are used or the CT has broken down.

Where does surgical robotics plus navigation evolve from here? According to Dr. Kutz, “At some point all aspects of surgery will be robotic assist. The technology will advance when artificial intelligence can recognize different tissue types.”


The Orthopedic Spine Surgeon: “I’ll Never Go Back”

Andrew Manista, M.D.

Andrew Manista, M.D. is an Olympia, Washington-based orthopedic spine surgeon who specializes in complex spine surgeries including revisions. He earned his Bachelor’s in music performance from University of Miami-Coral Gables, Florida. His M.D. is from Case Western Reserve University’s School of Medicine (where he was elected to Alpha Omega Alpha), his internship and residency was at Johns Hopkins and he stayed there to complete a fellowship in spinal surgery.

Dr. Manista got his first robot about five years ago. It was Mazor’s Renaissance—which makes Dr. Manista one of the most experience surgical robotic assist surgeons in the United States.

Like Dr. Kutz, Dr. Manista started his discussion of robotics with navigation. “Navigation is a very helpful tool. It’s good at showing where to place the screw. But it has no ability to control where the screw actually is placed.”

“I do a fair number of revisions and I’ve seen plenty of cases where the surgeon used navigation but still did not get the screw placed where it should be. That’s because you’re leaving the final judgement and placement to free-hand placement. If you divert your eyes from the screen while you’re drilling or you don’t have good conception of where your hand is, if you’re rushing or things have shifted out of place or something, you can have a mistake.”

We asked Dr. Manista how surgical robotic systems have evolved over the past five years and he spoke of Gen 1, Gen 2, Gen 3 and, yes, Gen 4 systems.

“The first-generation robots—the big one would be Mazor’s Renaissance—were very good at reproducibly putting you where you needed to be. Those early generations…hit their pedicle screw mark at a much higher rate than humans and minimized the human influence that contributes to errors.”

“Mazor’s Renaissance was very, very successful at doing that. You’ll never going to hear me say anything bad about it. I did good surgery with it for a long time.”

“The second-generation systems allow us to marry navigation to the robotic technology so that you have this combination where your hand is put in the right place and you can have the tactile feel of the unit going—like the drill going into the pedicle and you also have visual feedback from seeing where that is actually going.”

“The other big defining characteristic of the Gen-2 robot is that it no longer is mounted to the patient. You are truly free. I do some of the trickier things that people can do in spine surgery, so these systems allow me to spend more mental energy on the patient beforehand.”

“I would plan these surgeries while the kids were in ballet class and then a couple of days later, we’d perform them. My mental energy was spent on “Is this the right screw? Is this the right place? What’s the optimal trajectory? How can I get the biggest screw with the best bite and in the optimal position for what I want?”

“All that mental energy took place at a time remote from when I was in the OR. So, when I went into the OR I could concentrate on what I was really there to do. And that was to correct the patient’s deformity. Get the pressure off the nerves. Get that patient safely on and off the table.”

While that was not the reason Dr. Manista has bought these systems, it’s probably the biggest benefit, he says.

Choosing a Second-Generation Robotic System

When Dr. Manista decided to move from a first generation to a second-generation system, he initially headed to the Mazor X.

“When it came time to upgrade our system, I assumed we would just go for the Mazor X. We asked for Medtronic’s best deal, which they gave us but before we got an ‘ok’ from our hospital, they said, “The Medtronic’s deal is doable, but just to be thorough, what else is out there?”

“I went out to look at Globus’s robot in Philadelphia and I came away from that visit going, “Wow!” All the things I had wanted in a Gen 2 robot were already there. And you’ve got to keep in mind this was a couple of years ago, and the Mazor X did not have any navigation at that time. I walk into Globus and boom it’s there. It was incredibly easy to program. And fast.”

Third and Fourth Gen Robotic Systems

“The third-generation robots, in my definition, is where you can program the robot to do something, punch a button, or pedal, and then the robot will perform that task exactly as you told it to do. I think Gen-3 is where I program in “I want to do a laminectomy, and I want it to be 3mm away from this recognizable boney segment and 5mm from this recognizable boney segment. And I want a depth of ‘x’ millimeters and in one piece. I’m there, I’m present, but not actually doing it.”

“I want to be clear I’m not sharing any sensitive information or corporate secrets or any of that. This is Andy Manista’s opinion about where I think the technology should go. As for Gen 4, it would be like the movie “Alien: Covenant” where the lady is injured. She gets into a tube. It scans her body and then performs an operation on her. Start to finish.”

How Has Robotic Assist Changed the Practice of Spine Surgery?

We asked this question of both surgeons and Dr. Manista brought up a very specific procedure—the lateral approach spine surgery.

“I’ve been a fan of lateral for a long time. I get revision patients with subsided PEEK implants and I find that the lateral approach is a pretty powerful technique. But fixation is the biggest challenge. So, Globus came to me and said and we can do lateral cases with the Excelsius’s robotics with navigation system.”

Unexpected. Traditionally, with the kind of complex cases Dr. Manista takes on, patients stay in the hospital two days.

The Excelsius changed that.

As Dr. Manista explained to OTW, “Now, with the Excelsius system, our typical lateral patients stay overnight. With the Excelsius free arm, it doesn’t matter what position the patient is in, the screws are placed accurately, reproducibly. Using the Excelsius in one of my lateral revision cases, I had one of the epiphanies, I’ll never go back to free-hand lateral. Same surgery—lateral approach with pedicle screws—but in half the time and less positioning.”


Robotic Systems Are Wearing Well

It is notable that, instead of weakening their appeal, the longer these two surgeons used robotic assist systems—notably the ones that combine navigation and robotic arms like Globus’ Excelsius, the more they liked them, the increasing variety of cases where they employed them and the perception that error rates and hospital stays have declined sharply.

And, we’re only on Gen 2.

Stay tuned, for sure.