Christopher DeWald, MD at Midwest Orthopaedics at Rush talks about the Mazor X system and how it works.
Interview conducted by Ivanhoe Broadcast News in April 2019.
How does this technology work exactly?
CHRISTOPHER DEWALD: The robot is actually a surgical assistant tool. The robotic assistant is not a robot that functions like a movie robot. For instance, a lot of people assume that the doctor is in the next room while the robot does the work. But in reality, what the robot does is allow us to place screws in the spine in a more exact and efficient way. It’s a computerized technology that matches a CAT scan preoperatively with an intraoperative x ray to match the x ray with the CAT scan perfectly; We are able to preplan where we’re going to place the screws on the CAT scan ahead of time. This allows us to place the screws in the exact 3-D anatomic placement instead of trying to do it based on the visualized outside portion of the spine anatomy alone, which is the standard way. We look at the anatomy and we find a place we want to put a screw into the spine; we want to place the screw down safely into the bone. The robot accurately allows placement of the screw with less risk of touching the nerves or missing the bone. Sometimes the bones where the screws are placed can be very small or thin, and you need the exact, precise placement of the screw within less than a millimeter.That’s what the main purpose of the robot is. The technology is complicated but fascinating because the computer will match this vertebrae from the CAT scan with the X-ray we take in the operating room, this allows us to place an instrument on the spine and the computer will line it up exactly where we want to put it and place the screw into it. The nice thing about the robot is that each vertebra is individually matched to the preoperative CAT scan. To explain this in other words, the technology allows the exact matching of a preoperative CAT scan with an intraoperative x ray to help place the spinal screws safely and quickly.
Why did you decide to use robotic technology?
CHRISTOPHER DEWALD: Mainly for the reasons we just talked about. I do spinal deformity surgery, in which we treat very large spinal constructions, complicated anatomy, and twisted spines that we’re trying to straighten out. Now I am able to do that quicker – at least place the screws quicker and do it safer. For instance, sometimes the spine is very rotated which makes it difficult to place the screw into, therefore we have to take multiple x rays while trying to place each pedicle screw. We would bur a little bit on the outside of the and bone and would take a little instrument to feel our way through the bone marrow of the pedicle of the bone to get into the vertebral body. If it’s very small, you do it a little bit. Sometimes you take an x ray and we have to repetitively take x rays to know that we’re in the safe zone, within the bone and not in the spinal canal. The computer can do this process much quicker with less x rays to place the screw. I personally looked at it as this is the forefront of many technologies going to robotics. It’s a safer way to treat my patients. When I do larger cases, we’ll put in 20 – 25 – 28 screws sometimes. If each screw can take up to 15 minutes to 45 minutes if it’s a difficult screw, the robot can speed up that process to enable me to get to the part of the surgery where I can actually correct the spinal deformity. Sometimes we have to place long rods with multiple screws for very complex spinal deformities on both sides of the spine; this takes a lot of time to place therefore, if we have a curve that I’m trying to straighten out, we could put all the screws in quickly, and get to the main purpose of correcting the spinal deformity. The screws allow us to hook the rod up in between the screws to get the correction of the spinal deformity, which allows me to get to the part of the surgery that’s most important; the spinal correction. This is what caught my eye. In the future, I hope that it’ll place the screws for us, to allow us to make certain cuts in the spine, that will allow us to straighten out the spine in a more efficient and safe manner. This speeds up the time, decreases radiation and risk to the neural elements. To me, it’s a homerun and it can only go up from here. I’d rather be at the forefront of this knowledge and technology and advance my own techniques as well as to improve my patient outcomes.
How does this benefit the patient?
CHRISTOPHER DEWALD: There’s a number of benefits, not just to the patient but to the surgeon as well. Less radiation in the operating room is an important one because we’re not x raying for every single screw. As I said, sometimes, when placing spinal screws, if it’s a small pedicle, could take extra time. For each screw, we’re taking an X-ray to make sure where the position of the probe is, then we take an X-ray before we put in a screw, and then we take another X-ray to make sure the screw is in the right location. That’s a lot of extra radiation, not only to the surgeon but to the patient who’s laying there. The main advantage regarding the patient themselves is less time in the operating room and safer placement close to their own neural elements. One of the risks of spinal surgery is nerve injury and some of those risks are related to screw placement. The screw has to be placed in the proper place; if it isn’t or it’s pushing up against a nerve, you can have some weakness or nerve injury. If the patient has nerve weakness due to a screw, potentially the patient would need to be taken back to the operating room to change that screw. If the robot could place the screw perfectly the first time, it takes some of that risk away from the patients. Most proficient spine surgeons can use the standard technique of placing screws freehand with X-ray confirmation, in fact, we do this every single day that we do spinal surgeries. However, if a robot can speed up that process and do it safer, how can you not want to do that?
How does it enhance spinal fusion surgery?
INTERVIEWER: It enhances spinal fusion surgery by speeding up the process. It doesn’t help the bone healing so it doesn’t help the fusion aspect; as the fusion aspect takes months to make the bone heal together. However, if you think about rods and screws as an internal cast holding two vertebrae together in one segment; this has four screws (two on each side) and a little tiny rod in this case. This example is not a spinal deformity. We put bone graft out along the side to help this heal; the rods hold the spine like a cast would hold a broken bone and allows this to heal and “fuse” together. It doesn’t do anything for the fusion that still has to occur, but it really comes down to how fast we can put our instrumentation and the safety of it. The robot allows us to do the instrumentation part in a more efficient and safe manner but it doesn’t affect the overall fusion rate. It can allow us to get patients out of the operating room faster, which allows them to have a quicker recovery if they have less operative time. Most importantly there is less blood loss for the patient because, in the long spinal fusions for spinal deformity, every minute that we’re spending time putting in instrumentation, there’s more blood loss which results in more time in the operating room. There will be decreased cost and blood loss if we can help put the instrumentation in quicker and get to the most important part, which is the correction of the spinal deformity itself.
Who are the best surgical candidates for this technology?
CHRISTOPHER DEWALD: The best surgical candidates for this technology are still being determined. Some of my partners who do smaller, minimally invasive cases are using it now for some of the small cases – a one level fusion. I use it for very large cases; if I have to put in multiple screws, 15 on each side, it’s going to save me time, and each screw is a risk to the nerves, so this helps decrease risk to the patient. It works for minimally invasive surgeries and larger spinal surgeries, and it works for unique anatomy as well as, for congenital anomalies where the bones are not normal that you need a CAT scan to look at the bones ahead of time. It works for many different indications and I think we’re still developing who is the best candidate. From my personal point of view, it works for very large deformities with the need of multiple screws because of the efficiency and the safety of it. It also works with very small bones to put the screws in because it usually takes us the longest to manipulate the screw into small bones; if the robot can help us do that, it will decrease the amount of time in the operating room.
What was Jack’s diagnosis?
CHRISTOPHER DEWALD: Jack had a congenital anomaly called spondylolisthesis, meaning he was born with abnormality of the bone and one vertebrae started slowly slipping on the other over the years, which made the angle of the vertebrae difficult to get to from a standard open surgical approach. Although I’ve done that for many years, it’s just difficult and takes extra time to get the X-ray to make sure you’re putting the screw in the proper place. The robot allows us to line it up beautifully and quickly, it allows me then to get to the most important part for Jack. Because of the slippage, he was developing severe nerve compression in the spinal canal and the surgery was to take pressure off the nerves. However, when removing bone the slip may continue meaning you have to do the a fusion to prevent further slippage. The robot allows me to place the screws in a very difficult, unusual, and bony anatomy. This allows me to get to the work at hand which was nerve decompression taking the bone off to the spine to relieve the nerves.
How complicated was this condition?
CHRISTOPHER DEWALD: Jack’s condition was complicated. It was a standard type of spondylolisthesis. However, he had some unusual characteristics with the congenital anomalies of his spine, which made screw placement difficult.
Why did you use technology in his case?
CHRISTOPHER DEWALD: Jack’s spine was unique because of the congenital anomalies. Robotic technology allowed me to get to where I’m taking the pressure off the nerves when I’m fresher and less fatigued from trying to place the spinal instrumentation. His real problem was his nerve compression, which I was able to get to quicker and with less fatigue.
What would his surgery have been like without the robotic technology?
CHRISTOPHER DEWALD: In Jack’s case regarding his surgery it would have been very similar. But I think I would have struggled more placing the instrumentation and the screws because of his unusual spinal anatomy. In Jack’s case, without the robotic technology, we would have done the surgery in our standard way, which would’ve been fine but would have taken us longer to do it. I wouldn’t be as certain where the screws were being placed without multiple X-rays. Therefore, the radiation and the time involved would have taken longer. I still believe that at this point the robot, the major technology, is an assistive technology; it allows us to do what we usually do but faster, more efficient, and safer. It’s not doing something that can’t be done without it, but it gives the surgeon a tool to help the patient.
What is the takeaway message for the viewers?
CHRISTOPHER DEWALD: The takeaway message is that safety is most important in spinal surgery, Safety and decreased operative time. From the surgeon’s perspective our takeaway is that we get to what really counts most. As we get the screws placed quicker, we get to fixing the problem, the deformity, and/or the nerve compression quicker, then spending extra time on placement of the instrumentation.
END OF INTERVIEW
This information is intended for additional research purposes only. It is not to be used as a prescription or advice from Ivanhoe Broadcast News, Inc. or any medical professional interviewed. Ivanhoe Broadcast News, Inc. assumes no responsibility for the depth or accuracy of physician statements. Procedures or medicines apply to different people and medical factors; always consult your physician on medical matters.
If you would like more information, please contact:
Ann Pitcher
630-234-4150
Sign up for a free weekly e-mail on Medical Breakthroughs called First to Know by clicking here
