Robots Among Us: How Robotic Technology is Improving Hip and Knee Replacement Surgery
(bright music) - [Erik] Acquired Mako, which was the first robotic technology when I was there. And a lot of the guys that I trained under were very early on in the development process with that. So I got a lot of pearls of wisdom from the people who essentially helped create this stuff. Here's a little bit about the joint replacements, joint replacements at Eisenhower. I purposely left 2020 data out of this because there's a lot of ups and downs, for obvious reasons. We continued to do joint replacements throughout COVID.
We had months where we were totally shut down and then months where we were really busy. I would say the biggest thing that has really changed for us is the target. If you look at the very top number, top line, length of stay for total hips is 1.25 days. And in 2018, it was 1.88 days.
We're really getting down to less than one day for total hips and total knees now. And a lot of people are going home the same day with a hip replacement and a knee replacement. And that's partly driven by CMS, et cetera, for Medicare Services, as well as patient preference. And with COVID, people haven't wanted to stay in the hospital. And they've actually done really well going home the same day. So very low mortality rates, very few complications, far, far below the national benchmarks for all of these things.
Very low surgical site infections. The national average that target for, you know, this comes up often, average hospital infections are around 2% across the country. In 2019, it was less than a half a percent, 0.44% for all joint replacements. So we've done very well with infection management and whatnot.
A lot of things come up about infections that people hear, that Eisenhower has a lot of infections or whatnot. We take care of a lot of infections, but they weren't really treated at our institution initially. We're a big referral base for many, many places.
So we actually capture a lot of the complications that occur elsewhere and we take care of those. So we do see infections, but fortunately for us, it's not often ones that are created here. So in 2019, we're a Medicare five-star hospital. We've done very well with maintaining all these prestigious awards that come from CMS.
We're a Joint Commission Certified Center of Excellence for hip and knee replacements, and the hospital, overall, has done very well with all their credentialing. So we'll get onto the good stuff, the robots. So what are we using robots for in surgery and how is it making us better? I think that that's the big question. Well, I pose that question with another question, is that, can you think of an industry that's adopted robotic technology that's abandoned it? And you really can't, anywhere from manufacturing processes. And it's been a phenomenal development. It really helps with consistency.
So robots, we see them on the roads now, you know, self-driving cars is the wave of the future, autonomous driving. And Tesla is one of them. And we're starting to see that these things are probably safer than a human.
They have faster reaction times, and these things appear to be much safer. And I think the same is true of medicine. I mean, have they worked out all the kinks with the autonomous driving? No, they haven't, but I think we're gonna see with time that things are gonna be really nice.
So, again, we're gonna talk about robots in all sorts of surgeries, general surgery and pulmonary-related things. What are we using them for in orthopedics? What exactly are they? How do they work? Why they're gaining in popularity. And the big question, again, is do they make us better? So outside of orthopedics, you're seeing a wide array of specialties in medicine use robots, general surgery. People are using these things for laparoscopic procedures. You can do a single incision through the belly button and do quite complex operations.
I know a lot of gastric bypasses are done this way, a lot of appendectomies, hernia repairs, it's pretty amazing technology. So I'll get into everything. I have little snippets on all of these things. So, again, in general surgery, colorectal procedures. I would say it's amazing.
Dr. Bobby does a lot of the gastric bypass surgery at Eisenhower, and the size of patients he's able to operate on because of the robot is really amazing. And some of the other procedures throughout medicine.
So when I talk about general surgery and gynecologic surgery and urology related procedures, it has to do with what's called the da Vinci robot. It's different than what we use in orthopedics. So people ask about this all the time, and the da Vinci robot is a true robot. So this is an example of what it is. The patient lays on the operating room table, just as this, and you have all these robotic arms that come in. Now, this is an older version of the da Vinci.
from what I understand, I don't do this type of procedure, but now they've got it down to where there's one little arm that drops into the abdomen and it's got several arms that sort of branch out from that. And it's quite amazing stuff. So they can do a very complex surgery through one little portal incision through the belly button now.
The surgeon actually is not scrubbed into the procedure. He's off in the corner looking at this robot. And what's in the robot is there's several little cameras that they can have access to. And that's what the surgeon is looking at, it's the feedback from those cameras.
And then his hands are used to drive the robotic arm. So he's basically guiding the robot just like a video game and being very, very precise with what he's doing while in surgery. So this is an example, is a true operative picture.
And, again, this is an older arm. It looks like there's a bunch of little arms coming down in the abdomen, but now, with the newer renditions of this, they've consolidated those arms down to one small arm with a bunch of little, essentially tentacles that come out. It's pretty cool. They've done kidney transplants through robotic surgery.
I mean, the things that they're getting down to and they're learning as, you know, this is a whole new skill. So everyone that was really upset with their kids growing up playing video games, I mean, this is the video game of the future. So you definitely have to have a new clinical appreciation for being able to use these things safely in surgery. So one of the new technologies that came out, it's a completely new robot.
And this rolled out, I believe, in 2019 at Eisenhower. And Dr. Thomas was a big champion of this, it's doing robotic bronchoscopy.
So they have used, again, a little remote control down on the left. And you slide these little tentacles down the pulmonary artery to the pulmonary tree through the airway and you can control where these little tentacles go. And it gives really phenomenal feedback. This is the surgeon kind of advancing its way down the airway, and they can be very, very precise with where they're going. So to the left is a video of the true anatomy.
To the center, upper center, it's showing where it is and the location of the pulmonary tree. And down is kind of a three-dimensional picture of what you're seeing. So it's really, really slick technology that can be very precise with this. So they can get to places that they were never able to get to before with standard bronchoscopy because the probes are so much smaller and it can be very, very fine.
There's very accurate and fine precision with this. You can see better now than you could with traditional bronchoscopes, and you have very, very good control of this. This stuff is very precise. Before, when they were doing these bronchoscopies, the older bronchoscopies, you kind of have to, it's kind of a clunky arm that you have to control manually.
And there's wires in there that create where that bronchoscope goes. And they're much bigger, so they couldn't have the depth of reach nor the precision that they can with this new robot. And they can target little pulmonary nodes that are really, really far off in the distance, in terms of how small it is and how far away it is from the main airway. It's really cool.
So this is something that Dr. Thomas can really go on quite a bit for. And this is just some of the examples of how this sort of technology is making our lives as doctors easier. And I truly believe that it's better for the patients. So what are we using it for in orthopedics? So there's really one platform that robots has really come to fruition in.
A second platform is starting. Hasn't had a huge adoption yet, but the initial robot for joint replacements, and that's the platform, is joint replacement surgery. So the initial platform when it first came out was partial knee replacements. And that has now been out for over 10 years. And there's clinical data on these things and they've done phenomenally well when they're done robotically, been done robotically. Now, the full knee replacement, there've been renditions of this, but this really only started coming on the market about two to three years ago.
It's been out in full force now for about five years, but it's been in a really limited release. We're just starting to get data on them. The total hip was the second platform in joint replacements to come out. And that came out about 10 years ago, as well, but this was a little slower to take on.
When this came out, there was a lot of technical issues with the robot and it had kind of a slow takeoff. The nice thing is that this stuff has sort of been worked out. It's much, much more fluid and much more reliable now. I know that there's plans to develop, and they're currently developing shoulder replacement robotic surgery.
And then the future is sort of ankle replacements and other smaller joint replacements. Spine procedures are starting to be done now robotically. There's some testing of certain robot types, early FDA testing with spines, but nothing that's really widespread yet.
So what's a joint replacement? So what happens in the human body, and I'm kind of a simpleton when it comes to explaining this sort of thing, is that if you think of cartilage as the tires on your car, and what happens when you have full thread on your tires, you have a really healthy joint. But as you get down to the wear bars, you start to wear your cartilage out. The cartilage becomes less smooth. So cartilage is a really smooth surface. It's got a very low coefficient of friction, so it's a very slippery surface.
And that allows your joints to move relatively pain-free. As you start to wear your hips, knees, ankles, shoulders out, all these things, the cartilage starts to become sort of pitted and roughened, almost like sandpaper. And that sandpaper creates friction and it causes inflammation in your knee or hip or whatever joint it is. And that inflammation is what causes pain. And eventually that inflammation can cause swelling, it can cause things like stiff joints. But, essentially, arthritis is a disease where the cartilage is wearing out in the joint.
There can be many types of cause, it can be genetic related. That's why some people wear these out. It can be inflammatory, such as rheumatoid arthritis.
It can be post-traumatic if you hit your knee really hard when you were 25 playing soccer or something like that. Sometimes you have the end effect, and that's, you're wearing your knee out. What I tell people, you know, people come in all the time and they're in their 70s and 80s and their knees are worn out and they're asking me why this happened to them.
Well, you know, we haven't really evolved long enough, we haven't evolved to keep our joints around long enough. Up until about 100 years ago, you know, people were living into their 50s, mid 50s, early 60s. It wasn't as big of a problem.
Now, people are living into their 70s, 80s, 90s. I've done a joint replacement on someone as late as 97, but very healthy. Age isn't really a factor. It really has to do with how healthy you are and physiologically active.
But what ends up happening is that these things wear out. And we have good solutions for them. So when it comes to the knee, there's all sorts of different options.
You have partial joint replacements, which are kind of in the middle. I will tell you, once you start to get a little bit of arthritis, people always wanna get it cleaned up or whatnot. Knee arthroscopy is actually, in the setting of arthritis, can hasten the need for a joint replacement. So I tend to really, with very few exceptions, I tend to try and talk talk people out of doing knee arthroscopies because most people who have a little bit arthritis who go in to get an arthroscopy end up needing a joint replacement faster, because you're essentially going in and you're trimming out cartilage. So you're taking cartilage away, and you don't have a lot to start with. So there's partial knee replacements, that's, you can do the inside part, you can do the outside part of the knee, you can do the patellofemoral joint.
So on the far left here of your screen, that's a medial joint replacement. In the center, that's a lateral joint replacement. And in the right, that's a patellofemoral replacement. And then when more than one part of the joint is worn out, we do a full knee replacement, which is all the way to the right. So what's a hip replacement do? So if you think of the hip as a ball-and-socket joint, the ball, just like the knee, has a layer of cartilage. All these levels have layers of cartilage.
There's cartilage on the cup side of the hip and there's cartilage on the ball socket part of the hip. The hip socket is a ball-and-socket joint. So as that cartilage wears out, it creates that sandpaper-like effect, which causes inflammation, pain, and stiffness. And it's, essentially, wearing your tires out in the hip.
So here's an example of a hip that's worn out. So the things that we look at when the hips are wearing out is, there's thinning of the cartilage. So if you look on the outside, the joint replacement, kind of towards the top center of the ball is thicker than it is towards the inner side of the ball. You can see that this femoral head, or the ball, is not perfectly round.
All of these bone spurs and what we call osteophytes, they're a reaction to the body's inflammation, and they form bone around these things. Because what happens, when the body feels pain, it wants to stabilize that pain. So it forms this bone to sort of stiffen it up because it doesn't want you using it because it is causing pain. So, you know, that's the whole point of like fracture healing and stuff. That's why when you break your arm or whatnot, you don't wanna move it. Well, the hip's the same way, the knee is the same way.
They form these bone spurs to try and stiffen it up so it doesn't hurt nearly as much. It's the body's way of dealing with worn out joints. What we do in the hip replacement, we take the ball and we take the socket completely out and we put a brand new ball, which is anchored in with this stem that goes down the femur. You have to have a way of anchor it. And there's a cup. Now, some people do ask me about hip resurfacings where we don't put the stem in and we just basically put a cap on the femoral head.
There are very limited indications for those, in my opinion. For one thing, it's not a good procedure to do in women. And it's really not a good procedure to do, and that's in any women, and it's not a great procedure to do in men over 60 because there's a lot of concern about fracturing the femoral neck. So we just bypass that here. Typically, the patient population out here, it's just better to do a full hip replacement.
The other issue with the hip resurfacing, it is a metal-on-metal bearing. So if you look at the news, metal-on-metal hip replacements have gotten kind of a bad rap in the past. And there can still be some problems even with the current hip resurfacing technology, so I tend to stay with regular hip replacements in people that wear their hips out. There's too many issues regarding hip resurfacing procedures for me to even touch on that. So how are joint replacements typically done? So the big thing that I really wanna emphasize here is that not everyone is created equal. There's different variations of anatomy, the angles at which the femoral necks come in, the angles that, the sort of femoral neck is what connects the ball to the rest of the femur.
You can have different angles depending on what your own bony anatomy is. These come in different shapes and sizes. The same thing's true with knees, the angle that your knees come in.
You see people walking around with bow legged knees or knock kneed, and there's different sizes and shapes and the rotational anatomy, all of these things make it a very complex thing. And, remember, you're a mixture of your mom and your dad. And no two people are the same. So you can have big variations in anatomy throughout the human population. So what we strive through when we do joint replacements, both on the hip and the knee, is we always wanna try and get the alignment well and we wanna get the leg length well.
So what we really wanna do is we will wanna make the leg as mechanically straight as possible. So that's when you're looking down and, basically, the weight bearing access goes through the center of the femur. It goes right through the center of the knee and right through the center of the ankle, because that's what distributes the forces the best. And we're pretty good at doing that. But, again, there are huge variations.
And sometimes this can be really hard to achieve with standard stuff, standard instrumentation in surgery. So how do we achieve that? Well, historically, and this is historically done before the age of robots, we template people. So we get an x-ray and we do overlays of what we do for these people.
So this is an example of a hip replacement. We overlay the cup, we get an idea of what the cup size is so we can plan for that, how it should look in the patient's pelvis, and where the stem is and where we do things like the femoral neck cut, where do we make the level of the resection where we take the ball out, where that stem should sit, all sorts of things. It gives us an idea how long the leg is, the left leg compared to the right leg. That's that line going across the pelvis there, is it tells us leg length differences. To be honest with you, it's a very crude way of doing it, but that's really all we have. And there's not a lot of other ways around that pre-robot.
Same thing is true with knees, that we do all these fancy resections and we rely on these variations in anatomy. And then we overlaid the implants we plan on using on these x-rays. But, again, it's very rudimentary. The 8.2 millimeters that you see on the screen and 9.7 millimeters is very arbitrary. That's not always accurate, because it has to do with where the patient is next to the x-ray, and you can't always rely on that.
If you look at this white disc kind of down, sort of in the right center part of the screen, you can sort of see three quarters of a disc. That's a calibration ball. And we use that to calibrate the size of the measurements.
That is very dependent on where the tech puts it when they're taking the x-rays. So, again, there's a lot of variations that can be introduced into the system when we're planning these things. So this is an example of how we traditionally do a knee replacement. This is standard, traditional instrumentation that we've been using in surgeons for the last 30 years. So you start with a saw, you put a cutting jig on the distal femur.
And once that cutting jig's through, so the way it works, in the top left, there's a pilot hole that you create. That pilot hole accepts a rod that aligns the cutting jig into an appropriate place. Once that cutting jig is in place, then you can pin it in place. And then you put the, then you take the saw through it and you start your cuts.
Again, it's very, very dependent on where that rod sits in the canal and it's dependent on how well it fits in the canal. And the idea is to give us a knee replacement that looks something along the lines of this. It makes the leg look reasonably straight, it gives them a good mechanical alignment, and it allows them to put equal weight across all their joints, not just their hip.
So what are robots and orthopedics, what do these help us with? What's the problem that we're trying to fix? So there are a couple of things, is that, in orthopedics right now, there is no robot, like a robotic machine that comes in and does the cutting, opens the skin up, puts the retractors in, does the cuts. 90% of the procedure is really still done by the orthopedic surgeon doing the incision and getting the exposure. What the robots help us do is, what I like is it helps us sort of color in the lines. It doesn't allow any sort of variation outside the lines.
It allows us to make very precise cuts on the bony anatomy when we're doing these things to prepare the surfaces perfectly because that alignment can, you know, even if you're off a couple of degrees, it can make a difference in terms of how people do and the longevity of the joint replacement. So it's a heavily supervised robot. We always have our hands on the robots when we do this. So I would say most surgeons, most good surgeons are fairly accurate and they're fairly precise.
So when they look at the data from these things, and they've looked at very experienced surgeons, most surgeons who have a very high volume can be accurate and precise. However, they still have outliers. They still have outliers.
You know, the scary thing, and when you look at big regional databases and national databases, we know that surgeons who have a lower volume practice traditionally have more complications. You know, if it's a really low-skilled, inexperienced surgeon, they're neither accurate nor precise. I would say the run-of-the-mill surgeon can be accurate most of the time, but not always precise. If someone's just not accurate and precise, they're probably doing something wrong. Something's ingrained that, you know, they're making the same mistake over and over again. But robots really help us be accurate and precise with the target, with executing the surgical plan.
The other thing with robots, it allows me to use fewer retractors. I do believe that they're less invasive. It's not nearly as much soft tissue tensioning. We're not getting the exposure that we'd historically have needed to do a safe joint replacement, because a robot really helps keep us out of trouble. What's the downside of the robot is that they are an added cost to the health system.
So not every health system has them because, number one, they don't have strong physician champions, number two, they're very expensive, and number three, CMS really has cut significantly the reimbursements for joint replacements for hospitals. So CMS is now making us send patients home the same day after a joint replacement. That's Medicare. You have to have qualifying medical comorbidities to be able to stay a night. And what's really happened with that is if the patients don't stay overnight, Medicare significantly limits the reimbursement that they give to the hospital. So these things used to be pretty good money makers for hospitals, and it's just not that much.
And these robots cost, you know, sometimes $1 million. So it is a huge cost and investment. Luckily, Eisenhower has really seen the light, and I believe that they also see that, too, it's a very technologically-focused healthcare facility that really likes to be cutting edge. And we actually have three orthopedic robots at our facility.
So it's really been a nice thing. So here's the robot that we have at Eisenhower, it's a Mako robot. I'm gonna touch on the other robots. So the nice thing about the Stryker robot is it offers hip replacements, partial hip, or hip replacements, partial knee replacements and full knee replacements. So other companies have different robots on the market.
Smith & Nephew has this NAVIO. All this does is partial knee replacements and knee replacements. It does not do hip replacements.
Zimmer has the ROSA. All they currently offer is knee replacements. They don't do partial knee replacements and they don't do hip replacements. Johnson & Johnson has a robot that's just now, it just received FDA clearance. And that only does partial knee replacements.
Most of the robots on the market, there's a couple that do only hip replacements or only knee replacements, but Stryker really gives us the widest range of options for patients. And this is a fully-automated robot that has not received FDA clearance yet. And I have a video of that later. So how does it work? So people, like I said, it's not like Johnny 5 from the Disney movie comes in and does a surgery. The surgeon's always standing next to that robotic arm. In fact, we're driving that robotic arm.
what it allows us to do, and when we do these things, we get a plan. So we get a preoperative CT scan with this robot, and it gives us a really good idea of what the patient's anatomy is. So it allows us to precisely size the implants.
So the top screen, top center screen, that's a Mako knee replacement, and it allows us to precisely put that knee replacement where we wanna put it. We can change the angles of the knee replacement. We can do all sorts of things where it fits the person's anatomy perfectly. The bottom center is an example of a partial knee replacement. So we come in and we have this little burr that burrs away just the amount of bone needed to do a successful partial knee replacement while preserving the remainder of the cartilage that's in the knee.
So the surgeon comes in. On the top right, the saw is what it looks like. You can see there's a little trigger on the top saw.
And what we do is we pull this trigger, and then that robot sets the alignment for those cuts to be made to be able to receive that implant. On the bottom right is that burr that you're seeing coming in for a partial knee replacement. Again, we drive that, but the burr won't physically, or the saw won't let us physically cut anywhere that's not intended to cut bone.
So this is kind of what it looks like in the operating room. It's a series of probes, the robotic arm, and then we also do have to put little satellite trackers on the patient's leg. So these satellite trackers are two little stab holes in the tibia.
And now I do all of the femur. You can see on the top left there's a sector, there's two little satellites with four little dishes on them, that now goes inside the main incision. So you only have two extra little incisions.
And those usually don't give people too much trouble at all. Here's an example of me actually using the robot. You can see the robot is setting the angle.
So it's setting the angle and it won't let me move past that. So I'm trying to. You can see that green box there.
It won't let me go outside of that green box while I'm using that saw. And that allows me to be very precise, because what's outside of that green box are things like important ligaments, sometimes an artery in the back of the knee can be there. You can really do some damage if you don't know what you're doing while you're doing these things or if you're not paying attention. And the robot really makes us a nice tool for us to safely do reproducible knee replacements. So you're like, "Okay, that's great.
Where's the proof?" And we're starting to see this proof. This is from partial knee replacement data. This is ten-year follow-up, or this is, at first, a one-year follow-up study.
And partial knee replacements, they typically have the biggest revision, for whatever reason. A lot of times people do them in inappropriate patients, but there's a huge technical side of doing partial knee replacements, and that's why we see higher failure rates with them. But you can see almost instantly, within a year in the Australian Joint Replacement database, the Mako robot had a much lower revision rate and failure rate than the other knee replacements that have been offered. Granted, the numbers are a little bit lower, but this has sort of held out. And we have ten-year data to support this sort of information now. So here's that fully automated robot.
Again, this has not been FDA approved. I took this at a conference about a year and a half ago. And this is on a model bone, and the robot's actually in and doing everything. The surgeon is completely hands-off with this, so it's pretty cool. That's what's coming down the pipeline.
Again, the big problem with this robot right now is it doesn't do hip replacements. And they've had some quality issues with it. I think they may be, if they haven't been cleared yet, they're on the verge of being cleared in the United States. But these things do, they do offer even more reliability. The problem with a lot of these robots, though, is that they're all limited on what kind of implants you can use.
The nice thing about the Stryker robot or Smith & Nephew's robot is that they have very good longevity on their implant. So here's the evidence we have building. We know that these things make us more accurate.
That's well supported by the medical evidence. They make us more efficient as surgeons because we're not going through and have to tinker with the knee and do re-cuts. If the knee replacement doesn't fit right, we don't have to go in and recut things. We're seeing that people are actually recovering a little bit faster with these.
It's less invasive, and people seem to have a little less pain because there is a less invasive aspect to it. I will tell you that I feel, since I've been doing the robotic total knees now for about 2 1/2 years of my practice, and I do feel that patients, in general, recover faster. I'm seeing more people coming in at two to three weeks after surgery not needing nearly the amount of narcotics that they once did.
So it's been very good for my practice. So that's for knee replacements. So how does the hip work? The hip's different animal. Knee replacements, it's a ginglymus joint. So what happens is that it has many different centers of rotation and many different aspects that come into it. It's a very complicated joint.
It's not just a simple hinge. So a hip replacement, as I mentioned before, it's really a ball-and-socket joint, so we have to replace the ball and we have to replace the socket. So here are the reasons why people get their hips redone. They come loose. That's the biggest reason, historically, is that they came loose, and they had issues with the materials that were being put in. Now, we've sort of solved the material issues.
Around 2001, 2002, they changed all the plastic in the hips. And the current generation of contemporary hip replacements have lasted a long time. Instability, you know, 1 in 10 hip replacements, historically, have dislocated. I mean, that's really, really high.
I mean, if I had 1 in 10 people dislocating now, I'd be run out of town. With the direct anterior hip replacement that I do, it's been years, knock on wood, since I've had a hip to dislocate. They're much more stable. We can tension the soft tissues really nicely. Infection, 10% infection rate.
Again, these are sort of older numbers. As you saw from us before, we're a very high-volume joint replacement center at Eisenhower. And, again, this is the breakdown of why these hips and knees got infected.
So it doesn't mean there was a 10% infection rate, this is just the reason why people get their hips and their knees revised. So when we do robotic planning, it's kind of similar to the knee. We have precise placement of the cup when we do this.
This is a look of the interoperative screen that we get when we do these robotic hip replacements. We can look at the precise placement of where we wanna put the cup. The cup inclination is what angle the cup goes into and how open or closed the cup is. We can precisely plan that so there's no overhang in the important parts where you don't want overhanging in the pelvis. Again, there's a robotic arm that comes in that we do this.
That robotic arm helps us prepare. We use this circular cheese grater to essentially prepare for the socket. And it perfectly prepares it and then it holds the cup in the exact position that you wanna impact it in when you impacted it in. And that's what you're seeing on the far right with the gentleman with the mount in his hand.
So this is a real-time picture taken an Eisenhower of what it looks like in someone's body. Now, you can see, with the robot, you don't necessarily have to have, you know, historically when we were doing these things, you'd have a lot more retractors in there and it's stretching all the soft tissues out significantly more. You don't necessarily have to have that.
In fact, this is taken of one of my colleagues, but I don't really even have any retractors. And I like to keep everything nice and loose. I have very minimal retraction to kind of slip it past vital things, but very little retraction, very little tension on the soft tissues while I'm doing these things. And then once the cup preparation is done, this is a picture of impacting the cup into place.
Again, that arm is holding a very precise angle relative to the pelvis. Now, again, you still have, if you look back, if you can see the little satellite dish, it looks like four little discs right in the top left of the screen. Those disks are telling the robot where the pelvis is in space.
When you go in and you do these things, you have to register vital points of the bony anatomy when you do this. And that registers and it goes back to the CT scan that you get before surgery and it sort of knows where you are once you've registered that. So that tells the robot where the human pelvis is relative to the robotic arm, if that makes sense. So here's what I do. I do a direct anterior muscle-sparing hip replacement, okay? So I do it on a regular bed.
People come in and they ask me, "Do you use the special table?" I don't use a special table. We have one. In fact, we're getting a second one at Eisenhower. I don't use it because I can go down and I can actually feel the leg lengths.
When people are on the special table, you cannot feel the clinical leg lengths. And I do think that that's a vital thing. The other thing is when you use a special, the table, it puts a lot of traction on the patient's leg. And there's been complications such as ankle fractures and a lot of other issues. So I stay away from using the special table. This is just, it works better in my hands.
And a lot of people are starting to adopt this way of doing it. So the patient's incision is, actually, if you see my hand there that's a brown hand, that's the side I'm operating on. Because the I'm doing a direct anterior, I have to put the little satellite dish for the robot on the contralateral pelvis, because I can't put it on the same side I'm operating through. Now, that's put in with three little tiny incisions that, it's less than a centimeter each.
They are about five millimeters, and five to seven millimeters in diameter, or in length, very small. It usually never gives any kind of trouble. And we just seal them up with a little glue. We take those pins out the end of the case, but that's how the robot knows that your pelvis is in space. And, again, when you do it through the front, the direct anterior muscle-sparing, this is how you position it.
Now, what is it looking at? If you look at the top over the anesthesiologist's head there, there's a camera that beams down to those satellite dishes. So that's how everything is known. Again, it uses the CT scan that you get before surgery, and you have to register the pelvis with other technology, these little probes. You'd take different points throughout, and it tells the robot exactly where the pelvis is in space. So, again, that's where the incision goes and this is where the array goes. Now, I'm taking it another step further.
I started doing the bikini anterior hip incision. And what that is, is it, when you look at the crease in the groin, it essentially follows that pathway. Historically, and I would say the majority of hips that I've done and the majority of anterior hips that people do, the incision runs the length of the leg. So it's perpendicular to that incision. And I started using this.
There's been a couple of papers coming out that said there's really no difference in function, because medically these look a little bit better. And you can see, this is just five weeks out, or three weeks out after a bikini incision. It basically meshes with the groin crease in this patient. So, cosmetically, you're not seeing these huge scars on the outside.
Now, I will say not everyone's a great candidate, but most of the people that I've done. Those people who have really large thighs, it's something that I tend to stay away from because it gets really, really hard to see. But, for the most part, this works well in 95% of patients. And that's the incision right there.
So you're like, "Okay, cool." What really makes me, it gets exciting, you know, the standard hip replacements are fun, but the robot has made really challenging surgeries a lot simpler. So this is a guy, I did this guy just within the last week. So it's very fresh in my mind. This guy had a history of a pelvic and acetabular fracture. So he had this acetabular fracture, and you can see that there are screws and plates everywhere in this guy's pelvis.
And you're like, "Wow, how am I gonna get around this?" I'm on faculty up at Loma Linda. In fact, we had a patient, not me, but there was another orthopedic surgeon who had something very similar to this. And it turned into be a five, six hour operation because they had to take all these plates and screws out, because as soon as they tried to prepare the pelvis for the cup, they ran into all these screws. And they were totally in the way.
And that's what happens when you have the free hand. Now, what's nice about the robot, again, this was a very efficient hip replacement that we did. I could use the preoperative plan and place that cup exactly where I wanted it.
I could see where those screws were. And you can see the really white areas. This is a picture of the CT. The green is the cup, and I'm placing that cup precisely where I want it, and I know I can avoid those screws.
So to go in and take these screws out, especially that plate that's running from the patient's top of the pelvis all the way, kind of towards the bottom of the ball above that plate that you see from the top, you know, well above the top of the ball down past the inferior aspect of the ball, that plate sits right next to the sciatic nerve. The sciatic nerve is which causes your foot to dorsiflex your foot. So when they've had surgery like this, everything in the back of the hip is really scarred down. It doesn't look like normal tissue. It all looks like a big rubber ball, and it can be really hard. I can tell you dissecting the sciatic nerve off of this plate to take that plate out safely can leave the patient with a really significant problem.
And they can have a foot drop, they can have a lot of issues related to nerve issues from nerve damage. What's nice is that, you know, and when going in and taking that plate out and those screws out creates a much bigger surgery with a lot more potential for complications. But, again, I'm able to use this robotic planning CT to plan where I wanna put the cup. I can say, "Hey, I wanna medialize this cup only five millimeters. I don't wanna go eight millimeters, because I'm gonna worry I'm gonna run into the screws." And we can really adjust where these cups go.
It's really powerful stuff. Here's where it is. And I can see exactly where that green outline of the cup's going. And I know I'm just gonna barely miss those screws. Historically, when you do this with the regular reamer, it's really, for lack of a better term, and this was a term my dad, who's an orthopedic surgeon, gave me that he learned when he was at UCSF in his training, it's very eyeballing.
You kind of look in there and you go, "Well, that looks pretty good." And you ream more. And there's a lot of skill related to that. But if you mess up and you hold your finger on that reamer a little too much, you go too deep and you're in trouble. Again, here's the 3D, here's a 3D overlay. This is the surgical planning.
You can sort of see the outline of all those screws. And it just looks like I'm gonna barely miss them with everything. I'm gonna really miss that plate. It's going around that plate. And here's a template of the stem going over it.
So it's very accurate planning. This will tell me, it'll tell me that, you know, with the 60 millimeters cup, I can use a 28 plus head. I can use a 28 millimeter head and a size 10 stem and it's gonna get me within just a couple of millimeters in the other hip.
It's very accurate this way. And here's what we did. I ended up doing this hip replacement very efficiently. I was able to avoid the plate. I was able to avoid taking any kind of plate out and avoiding any kind of complications. This guy has done really well with this.
It's very early, but we expect a speedy recovery for him. And when I mean speedy recovery, this guy right here is two weeks out after his hip replacement. He had a fused hip. Now he's 27, but, I mean, you can see what kind of function. This guy hasn't been able to flex his hip up for 10 years.
And he's a very resilient person, but I will tell you that's phenomenal. Two weeks, this guy was ecstatic. Again, he had a muscle-sparing direct anterior hip replacement. So that's pretty much all I have on the hip replacement side of things. We, as surgeons, always guide the robot.
The robot, not at least yet, has just taken over the surgery planning or anything along those lines. But it's basically guided surgery. It helps us really execute our surgery plan. We plan the case. We do the approach.
We register the joint with the robot. So that little satellite dish, you know, we tell the robot where all the important stuff is in the pelvis. It prepares the joint precisely.
The surgeon then goes on to implant the implants. The robot's not doing that. And the surgeon or RPAs help close the wounds. So the robot, again, is the preparation and, often, insertion of the implant. So, again, as I mentioned before, why are these things gaining in popularity? It helps reduce the outliers.
It helps us produce more accurate surgery. I will admit that there is a marketing side of things today. I mean, a lot of people like the latest and the greatest so there is a marketing aspect, but I do truly believe that this is where we're heading to in medicine.
And there's more and more literature that's going out supporting this. So to put things, you know, does this make us better? Do robots really make us better? That's the question. Well, the big thing that I'm gonna do, you know, you can look at all the published literature. And, again, over the long term, every industry that has seen robotic technology be introduced ultimately has shown an increase in production capacity, improved accuracy and precision, and lowers the cost, in this case, lowering the cost of Medicare. If we can reduce the number of redos that we have to do because the robots help us put them in, they're worth the cost. The newer generation of robots are really helping us do that.
And there's evidence to support that they are more accurate, improve patient satisfaction, lower complication, but it's really promising stuff. And that's pretty much it. That's all I have. To put things in perspective, Stryker started selling their total knee platform about three years ago globally. And they have had over 1,000 installations of that knee replace. Doesn't sound a lot, but, you know, you're talking about, most hospitals when they get them, they only get one.
We have three, but the majority of hospitals who get them, they just need one. We're so busy at Eisenhower and so many people are using it that we just needed that sort of capacity. But 1,000 joint replacements, they've done over 500,000 joint replacements robotically. And they've seen very, very promising results with them.
So I like the Stryker robot, not necessarily because it's Stryker, but because I think it's the best platform. And I think each of these robots are a different tool to help us put the joint replacement in an inaccurate way. I don't know if there is one that's clearly better. You know, we have our preferences.
And I think we'll take our questions now, Brett. - [Brett] Great, I don't currently have anything in the chat, but if you do have a question, please feel free to unmute yourself and ask the question to the doctor, or you can also put it in the chat and I can relay it to him. Don't be bashful.
And as a reminder, this lecture will be edited and on our YouTube page probably within the next two weeks, as well as our Eisenhower website. It looks like Nancy. Hi, Nancy. - [Nancy] I do, hi there. Hi, Dr. Schnaser.
You did my husband's hip, and I'm unfortunately gonna probably have to have you do mine one of these days, too. - [Erik] I'm sorry. - [Nancy] Well, that's all right. You know, with the improvements, it's not so bad. My question is, you talk about the anterior.
I know before you did the posterior. Is everybody qualified, or what happens if you can't do the anterior? - [Erik] I would say 98% of people, I do the anterior. I still do posterior hips if people break their hips.
That's a big reason. And the reason being is that the femur, at the top of the femur, when you have a broken hip, it can kind of splinter around there. And that can just be a little bit more of a dangerous situation for the patient for me to do anteriorly because it can be harder to deal with any kind of cracks that go down the femur. It's just a better approach for fractures. So I do all my revision work through the back because it allows more access. It allows more of an extensile access.
So that's why I do a lot of revision work through the back. And then fractures or if someone's got a lot of hardware that I may have to take out and it's positioned in the backside of the pelvis where you just can't fundamentally get to it from the front. There aren't too many contra-indications now where I'll do someone from a posterior approach. There are certain hard contra-indications. They don't come up that often.
I had a patient a couple of weeks ago, who, she came in and saw me. She had a BMI of 70 when she initially saw me. I told her three years ago that if she lost a hundred pounds, I would do her hip replacement. I never thought she would do it. She lost her hundred pounds, and then she came in with a BMI of like 60, which is still giant, but I kept my word and I did it through the front and she did phenomenal.
She stayed in the hospital one night just because of her weight. So weight, it actually really isn't a big contraindication for me to do an anterior hip anymore. It was when I first started doing them about five, six years ago.
But since that time, I've done several thousand anterior hips and I feel very comfortable with it. - [Nancy] I'll try not to break my hip before I get to you. - [Erik] (laughs) Don't do that. - [Nancy] I won't. Thank you. - [Erik] You're welcome. - [Brett] Thanks, Nancy. So we have another couple of questions coming in, "How much more difficult is doing a full knee on a patient that has had a partial?" - [Erik] That's a great question.
I usually typically use the robot to do a conversion from a partial to a total knee. Now Stryker, technically, that's an off-label use of the robot, but Stryker has let us do that. They've been threatening to not let us do that anymore, but generally speaking, it all depends on how well the partial was initially done. So you can do a partial where you take a lot of bone and you really go down and you take a lot of bone and they put a really thick plastic in to build that bone up. That's a much trickier situation than someone that had, for instance, a past robotic surgery of, say, like 10 years ago where they were learning these things or they just happen to wear the rest of their knee out where they took very little bone. So it depends, but generally speaking, what the literature says is that people who have partial knee replacements converted to a full knee replacement tend to have a similar recovery as people who initially have just a knee replacement.
It's not necessarily any more difficult. And, again, they are special situations, but for the most part, people seem to do about the same as regular knee replacement. You definitely wanna have it done by someone that knows what they're doing.
Again, we do a lot of revisions here. In 2019, I did like 125 revision hip and knee replacements. So it's considered a very high volume redo practice, and you wanna go to someone that knows how to get around all the potential pitfalls.
- [Brett] Great. Thank you. - [Erik] Then your recovery is about the same. - [Brett] How long do replacements last? Should a person be strategic about when to have it done? - [Erik] Yeah, that's a good question. So the historical data says that people who have hip or knee replacement before the age of 55, they're gonna wear those things out.
I don't know if that holds true anymore, because baby boomers were so active. But what we know is that the implants that were developed about 20 years ago still have a very high survivorship. 97% of them are still walking around who don't have them revised for infection or they fall and they break the implant or they do something. But for just normal wear and tear, very, very high survivorship at 20 years at this point. And that's data that's registry driven, mostly out of the Australian registry. So they've been lasting a very long time.
So, you know, it's about quality of life years now versus quality of life years later. I mean, do you wanna save all your money now so you can live a great life when you're 80, or do you wanna spend some of it and save some of it? Because some of us may not make it till we're 80. And that's the type of thing is that you're not doing yourself any favors if your knee or your hip is keeping you inside for your 50 or 60s. And then you think, "Well, I'm gonna get this replaced when I'm 75, that way I can really enjoy my life then."
you may not be around to enjoy it. So I tell people when you stop living the desired level of activity that you wanna do, like you can't go play golf anymore, you have a hard time going the store, you have a hard time just going out and doing things that you used to enjoy because of your hip or knee replacement, you should really think about getting it done, because it's a death sentence being stuck at home and not moving around. The key to staying young is staying physically fit. It really is.
- [Brett] Great, with a knee replacement, if the quadriceps are separated from the knee, can the robot reattach those? - [Erik] No, the robot doesn't do things like that. It doesn't do any muscle work. It doesn't do any sewing of soft tissues. It's purely a saw. It's a guided saw that gives us precise cuts.
The surgeon is really the one that repairs soft tissue at this point. There's not really a robotic way to repair those yet. - [Brett] Great, what is the difference in recovery, rehab, and pain on a full versus partial-knee replacement? - [Erik] That's a good question.
So a partial-knee replacement, we're essentially replacing a third of the knee. So the pain tends to be less. The recovery seems to be more, or it's more expedited. I mean, I have a video of one of my patients ballroom dancing four days after his partial knee replacement.
Is that normal? No, but people tend to recover faster. A partial knee feels more like a normal knee than a full knee replacement, because there's just less mechanical parts in there. So I'm a big fan of keeping as many of your pieces and parts as possible because they generally work really well. But if you're not a good candidate for a partial, you're not really doing yourself any favors for pushing for a partial, because you're still gonna have, you know, potentially symptomatic pain from the other parts of your knee that were worn out.
- [Brett] You may have answered this, but does the robot do the ball part also? - [Erik] It helps us template the saw. So it tells us what length of ball we need to put on. That part is really not that technically difficult for most people. So there is one robot, THINK robot will take a special burr and it will prepare the femoral stem, but I don't know, that's not really all that helpful.
The robot helps us judge leg lengths, and that's what it helps us do. And you adjust the leg lengths by adjusting the size of the stem. And then the balls come in different lengths as well, so you can adjust the different types of balls. And the robot gives us where people started before surgery and how much we lengthen them, and it also gives us where they are compared to the others, the other hip.
- [Brett] Great, do knee replacement patients need to take antibiotics before dental cleaning? I.E. taking four amoxicillin for every dental visit? - [Erik] So, historically, there's been a battle between the dentists and the orthopedic surgeons. So it's been a very confusing thing, because there's a lot of data that says you probably don't need prophylactic antibiotics, but any orthopedic surgeon will tell you that they've had several patients in their lifetime who have had their dental cleaning and they come back two weeks later with an infected hip or knee replacement from the dentist and they're growing out bugs that came from their mouth. So what I tell people is I would recommend doing it for the first year, taking antibiotics, because while your knee is healing or your hip's healing, there's a lot more blood flow coming to that area. So your mouth is an open sort of super highway for bacteria to get into your bloodstream.
And bacteria love implants. They love heart implants and they love knee and hip implants because they can go attach to it and sort of live rent-free there and not have to worry about the immune system. So what happens is the dentists came out and they said, "Well, we know the orthopedic surgeons, we've always historically agreed." They've had a consensus with the orthopedic surgeons. About seven, eight years ago, they came out and they said, "No, we don't think you guys need any antibiotics."
The problem is, the dentists aren't the one getting up at Christmas morning to wash out some infected knee replacement from a dental work. So, you know, it's still kind of a controversial thing. What I tell people is I would recommend taking the antibiotics for the first year anytime you have dental cleaning, and then if you have good dentition and you have healthy gums, you could probably stop it after the year. Now, what I mean healthy gums is when you floss, you don't get any bleeding from your gums or anything like that.
I use that as sort of my marker. Every surgeon is still a little bit different in that area. I used to tell people to take them for the rest of their life. And I do think that that's a little overkill, so I tell people if they have good dentition.
Now, if you have aggressive dental work, I would still recommend taking, any kind of crowns, bridges, any kind of big implant type of surgery, any kind of oral surgery, I would still taking antibiotics. But, most of the time, the dentist will give that to you. - [Brett] All right. Those are the questions we have. We are at hour, so if we have any last minute question burning desire to be asked, please either unmute or send me...
Looks like we have one more question. This will be the last one, "About how many hip and knee replacements in a total have you done at Eisenhower?" - [Erik] Well, we're one of the highest volume. In total, forever? Boy, that's a great question. I mean, we do about 2,000 hip and knee replacements a year. When I got here, we were doing about eight, 900 a year. And we've really changed the quality, you know, put a lot of processes in place.
And I'm the director of the joint replacement program at Eisenhower. So we've really ramped up the volume quite a bit. We've acquired some really talented surgeons. But we do about 2,000 hip and knee replacements a year. And we've been doing that for the last four or five years.
We're usually in the top five high volume centers in California. Hoag is the number one, the highest volume. I think they do like 13 or 14,000 a year, but they have multiple sites that they count all as one. So it's hard to know what one center does.
- [Brett] Thank you. We'll take this last one. It's short. It's like, "How long until I can swim after a full knee replacement?" - [Erik] It depends on your surgeon. If you look like you're pretty healed up at three weeks, I'll let you get in the pool. - [Brett] Great. All right, everyone.
Well, thank you, doctor, for a very informative presentation. And, again, this will be edited and placed on Eisenhower Health website under the Physician link there, as well as on our YouTube page, probably within the next two weeks. And with that, everybody stay healthy, and we hope to see you on a lecture soon. Thank you. Have a great evening.
- [Erik] All right, thank you. All right, bye-bye. - [Brett] Thanks, bye.