Total Knee Design – Past vs. Present

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Toree: Hi. I’m Toree McGee, and this is the Rapid Recovery Report, sponsored by ROMTech, the modern technology of rehabilitation.

So, if you’re new here, we are doing this series on Thursdays at 4:00pm Pacific, 7:00pm Eastern, where we’re talking to a whole mess of people. Sometimes, it’s surgeons. Sometimes, it’s ROMTech experts. Sometimes, we’re talking to patients. And actually, if you would like to be a guest on our podcast, you can email us at [email protected]. We can have a chat, and see if you’d be a great fit.

To get back to who we are and what we do here, we are ROMTech, and we’ll probably spend a little bit of time today talking about our device, the PortableConnect. That right there. Isn’t she cute? It’s a high-tech recovery device geared to get patients moving and on the road to recovery faster. So, if you want to learn a little bit more about us, you can check us out at All of our information is below in the description box. And you can follow our social channels and all that good stuff.

Let’s get into the exciting part of our podcast here today. We’ve got a great guest that we love to introduce you to, so let’s get right into it.

Orthopedic Surgery Expert, Dr. Mitch Herrema

Intro: In sports, in order to be the best, you have to outwork your opponents every day, being the first to the practice field, and the last to leave the field without exception. People with this mindset are the people who can move mountains.

Dr. Mitch Herrema is such a person. A former star athlete at Michigan State University. A soon-to-be doctor knew exactly what he needed to do to be successful, and went after it full force. He became who he saw himself to be, serving as the chief of orthopedic surgery at Morton Plant Hospital. Dr. Herrema still incorporates the lessons he learned on the practice field. Be the first to show and the last to go. This is Dr. Mitch Herrema.

Toree: Based in Clearwater, Florida, Dr. Mitch Herrema is currently the chief of orthopedic surgery at Morton Plant Hospital. His expertise has led him to assist in designing implants, actually knee replacements with implant companies. You’re not the only Dr. Herrema in the house either, are you? Your wife is an accomplished neurologist.

Dr. Herrema: She’s a neurologist, yep. She specializes in movement disorders, mainly Parkinson’s disease.

Toree: Yeah, you guys are a smart couple. Well, thank you for being here with us today. We’re excited to talk to you.

Dr. Herrema: I’m excited to be here. Thanks for having me.

Toree: Yeah. So, let’s start out with this easy one. What drew you to orthopedics, out of all the options out there in medicine?

Dr. Herrema: Coming out of high school, I didn’t really know what I wanted to do. I thought I was going to be a pilot. I went to the Airforce Academy. I was there for six months, and I just kind of realized that my science classes were what caught my attention. One of my mentors there was premed, and so I decided to transfer to a civilian school, so to speak, Michigan State University. I was on the football team there. I started shadowing one of the team orthopedic surgeons, so that kind of got me interested in medicine. Ended up getting into medical school.

I kept an open mind. I thought I knew I wanted to do some sort of surgical specialty, but I kept a very open mind, all the medical subspecialties, surgical subspecialties, of course. At the end of the day, I thought orthopedics kind of suited me the most, and that’s where I am today.

Toree: All right, that’s a heck of a story, from a pilot to an orthopedic surgeon. Both are very very cool jobs you might get in.

Now, you were part of a joint replacement fellowship at McLaren, is that right?

Dr. Herrema: I did my residency training in McLaren Oakland in Pontiac, Michigan, but I did my fellowship, my joint replacement fellowship in Fort Myers, Florida.

Toree: Okay. What was the experience that you had there?

Dr. Herrema: It was a great experience. It was a very very high-volume community-type-based practice, which I knew is what I wanted to practice. I didn’t plan on going to a university, and being a part of a big training program, and doing lots of the research side of orthopedics. My mother-in-law, at the time, she lived in Saint Petersburg. Now, she lives right by us in Clearwater. I knew where I wanted to live, and be close to family, and things like that, so a high-volume community-based practice suit me the best.

We did several hundred joint replacements that year. If I include revisions and shoulder replacements, we did over a thousand. That really gave me the volume and the expertise I needed to practice where I’m at today.

Toree: Wow. That’s a pretty move from Michigan to Florida. A little bit of a climate change.

Dr. Herrema: Yes, it was, and it’s very nice. I don’t plan to go back, only to visit.

Toree: I believe that. Now, when we spoke earlier, you’ve mentioned a company that you worked with called NextStep. Can you tell us a little bit about what they do, and how you’re involved with them?

Dr. Herrema: Yeah, so NextStep Arthropedix. That is a company that was founded, I believe, in 2012. My fellowship director was close friends with the founder of the company, and so that’s how I got introduced to the company in 2014.

They started out with developing a hip replacement, which is now been out for several years. Then a few years ago, we decided we wanted to add a knee to the platform. So, I was asked to kind of help out with that design, on the design team. We’re hoping, within the next maybe 12 to 18 months, we’ll actually get it out, and start using it.

It probably would be out already without COVID. COVID kind of changed some things with design process and things like that, so the ability for the surgeons to get together, something like that to keep things moving. There’s a lot of exciting things in the company, and hopefully, in the next year or two, we can get it out.

Toree: Awesome. Yeah, that’s really exciting. We’ll have to keep an eye out for it. Is NextStep looking to maybe expand into all of the joints and all of that kind of thing?

Dr. Herrema: Right now, they’re focused on hips and knees. I don’t know where it’s going to go from there. It’s really getting a primary knee out initially. And then obviously, going full platform with revision, revision implants, and things like that. Outside, of the knee and hip, I don’t know where it’s going to go.

Toree: Okay, very exciting. I mean, it’s similar to ROMTech, right? We’re lower extremity people for now.

Dr. Herrema: Yeah.

Knee Replacement at Any Age

Toree: Now, when knee replacements first began, the average lifespan that they gave for the hardware was roughly 30 years old, I think at the max. What’s the lifespan for new hardware that’s being used?

Dr. Herrema: If you go back 20 or 30 years ago, a lot of the surgeons were saying you got 10 to 15 years lifespan on these implants, which we’re seeing now, a lot of these patients, if the joint was done well, put in correctly, we’re seeing these still look very very good at 20 years out, 30 years out even.

Some of the changes over the last decade or so has been the technology side of orthopedics, which is computer navigation, robotic surgery, and things like that that help us get rid of the outliers in surgery, so we can kind of put these joints in the most anatomic position, and not create offloading eccentric wear and things like that on the polyethylene. I think there’s very good 30-year-wear data on the polyethylene, which is plastic bearing between the implant, which is typically the limiting factor. There’s good 30-year laboratory data on that.

Toree: That’s great, because every once in a while, we’ll see orders come through for somebody who seems so young for a joint replacement. To be able to put off having to do a secondary replacement for the hardware is just crucial.

Dr. Herrema: It is, yeah. I have a lot of patients who’ll come in, and say they believe they’re too young, and they could be 40, and they could be 60. They just feel they don’t want to do a joint replacement, because they’re worried about having a revision surgery down the road, and I totally understand that.

I try to tell my patients that it’s all about quality of life. And if you’re 45 years old, and you’ve got a severely arthritic hip or knee that is debilitating, not allowing you to sleep, you can’t exercise, then that’s not a way to live. Rather than trying to push it off for another 10 to 15 years, just get on with your life, get a joint replacement, and enjoy life.

Toree: Yes, I agree. I mean, deeply, you think about hip and knee movement and needing the replacement, and what it impacts, and your brain immediately goes to like, okay, well, walking is difficult, and just general mobility, but it’s everything. Like you said, it’s sleeping, it’s sitting, it’s everything.

Dr. Herrema: Leads to weight gain, and of course, other body systems start to fail. You get overweight, and you’re not exercising. Your blood sugar and all those things are interconnected.

Toree: Yeah, absolutely. It affects everything. Now, when you’re working on your new designs, what was some of the improvements that you wanted to make from old designs to this new one, going back to the NextStep?

Dr. Herrema: Well, one of the things we looked at is creating a knee that has stability throughout the entire arc of motion, from full extension to full flexion. Then keeping this kind of ball-and-socket design, like the hip is a ball-and-socket joint very clearly. The knee also kind of works as a ball and socket as well, where the inside of our knee is kind of more of a ball and socket and the outside of the knee kind of goes along for the ride. Almost like your hip joint is the ball and socket, and the lateral part of your hip, the greater trochanter is kind of along for the ride. The knee is not a whole lot different. It’s almost like a hip upside down, the way the mechanics work. The polyethylene bearing is a little bit more constrained on the medial side, which kind of gives that more normal physiologic motion to an almost native knee.

Toree: Okay, that’s really interesting. Now, you have a really high-volume practice, right?

Dr. Herrema: Yeah, I got probably 300 to 400, 500 joints a year.

Toree: Okay, yeah. Well, I mean you came from a fellowship with really high-volume areas, that makes sense. Now, what are the typical ages that you see of your patients?

Dr. Herrema: I have done joint replacement on patients as young as 25. I think my oldest primary joint replacement was at a 92-year-old. The 25-year-old, it was more of a traumatic injury they had, and so that’s a little bit of a different story. Then you’ve got the 92-year-old. I told my patients, really age is a number. She’s super healthy. She drives herself. She barely even used a cane, but had a debilitating knee pain. Gave her a total knee, and she did great.

Recovering from a Joint Replacement

Toree: I mean, generally, what recovery times, on average, for patients? I know, of course, the more healthy you are, or the more fit you are before surgery, the faster you usually recover.

Dr. Herrema: Yup. The recovery for a knee replacement specifically, I usually say six weeks. Obviously, until you’re completely improved, you’re looking at probably more like three, four months, even up to a year. My patients will continue for about to a year, maybe even longer, but the first six weeks is pretty crucial. That’s when they start to feel like, okay, they can get back to work, kind of light duty types of things. Six weeks, most patients are really happy they had it done. First two to three weeks, that can be a little rough. Knee replacements are not a pleasant surgery. Most patients say they know right away. It’s surgical pain. It’s temporary. It’s different than that debilitating arthritic pain they had before.

Toree: Great. I mean, immediate rehab on a replaced knee is pretty important in your opinion, right?

Dr. Herrema: Very important. I think that’s something else that has changed over the last decade or so. I mentioned the computer technology we have now that we use robotics, and other types of computer assistance. But the rapid recovery protocols we’ve used, getting patients up immediately after surgery, working with physical therapy, getting them home, getting the therapist out to the home, keep them out of rehab facilities when appropriate. The rapid recovery protocol has helped a lot. It’s decreased incidence of blood clots, just allowed patients to heal quicker, and get back to life quicker.

Toree: Yeah, and I mean now we’re talking kind of about new tech and immediate movement, so it only makes sense to talk about the PortableConnect. You’re one of our first prescribers actually. What have you seen as far as patient outcomes after using the PC versus previously?

Dr. Herrema: Yeah. I think the closest thing I can compare it to is the old CPM machines, continuous passive motion. A lot of patients, still to this day, ask about them. They haven’t been used regularly in probably 5 to 10 years, but when I was in residency training, everybody got a CPM, which is a machine that you lay in bed, you hook your leg up to it, and it passively moves your leg. The problem with that is, I tell my patient, it kind of makes you lazy. It doesn’t require you to use any muscles. You can just lay there. They weren’t very accurate with the measurements, as far as the patient’s range of motion, and so it was a little deceiving in how well the patients were moving, and their muscles weren’t getting activated.
The PortableConnect was a perfect segue into what the patients were asking for. They really wanted that machine. This one forces them to activate their muscles, and be engaged in the therapy, as opposed to just strictly passive. I’ve had great feedback.

Toree: Great. I mean, I always wondered about CPM machines and the impact that they had on the healthy limbs. Because if you’re stuck in bed with the CPM machine for six hours a day, that other leg is not doing any movement, any action. You’re just having to lay there.

Dr. Herrema: Absolutely. Some patients realize that. They felt, oh, I don’t really think it’s really helping me much. But other patients, I think again, I think it was a little bit of a placebo effect. They’ve really felt like they’ve improved with that CPM, but if you really look at the data and their actual numbers when they would go see a therapist after those first couple of weeks at home, they really weren’t doing that great. We needed to get them more active in their recovery, as opposed to passive.

Toree: Yeah, absolutely. Do you have any like favorite patient stories, maybe someone who have used the CPM, or haven’t used the ROMTech for one knee, and then used it for another, or somebody that just loves the PortableConnect?

Dr. Herrema: I do. I’ve got several. When I first started using the PortableConnect, I had several patients that I had done a few months prior that, of course, did not have it on one knee, and ended up using it on the other side. At first, they were a little skeptical. Why am I needing this bike to come into the house? I did great with the other knee. Hearing them compare the two, it was not even close. They thought, wow, I feel like I’m really really far ahead of where I was with the other one. Overall, great patient feedback. I couldn’t be happier. They couldn’t be happier.

Toree: Great. Well, I mean they trusted you as a surgeon before, but probably after you told them, now, you should probably use this, they trust you with all of their kids, and their money, and their house.

Differences from Patient to Patient

Toree: With so many people who have had challenges with their weight, are there different designs for knees, or ways that you go about things based on patient weight, or age, or even like male or female?

Dr. Herrema: Well, as far as the male, female, there are some companies that offer what they call gender-specific knees. Really what that means is it’s implants, knee replacement implants that have a wider or narrow implant. You’ve got, let’s say, a knee replacement that is a size 4, and you can have a 4 narrow or a 4 wide, depending on male or female. It’s really not as gender-specific. It was kind of more of a marketing term. With that said, some of the narrow and wider implants have worked out really well. I do use some companies that have those options.

As far as patient’s weight, the actual implant is not different, but I think the specific constraints that you put on the joint, or the type of maybe a stem or a cement and things like that, if you think they’re really really going to be loading this implant a lot more, and your bones are a little bit softer, due to the obesity, and their inactivity and things like that, and you can use short stems and cement, and things like that, to give them a little bit more structure. The actual implants are the same.

Toree: Okay. I mean, I assume, just like you tell patients to try to be more active, because the healthier you are, as they’re prepping for surgery, the easy it is for recovery, you probably give them some sort of advice on, well, the less weight on a joint, the better that joint is going to last, the easier it’s going to be. Is some kind of like nutritional, or general kind of health or exercise regiment important for you to give your patients before they consider surgery?

Dr. Herrema: Yeah, so we talk about what we call prehab, and so we give them a handout of exercises we want them to do. Most patients, we don’t send to formal physical therapy before surgery. Maybe we try that as an alternative to surgery, prior to. Once they schedule surgery, we of course want to save those physical therapy visits for afterwards when they really really need it. We’ll give them a prehab workout, or they can take home with them a handout of exercises to strengthen the quads and hamstrings, and things like that.

Of course, any patient that has a little extra weight, I tell them, over the course of time, over the next 20, 30, 40 years of this implant, you think about an extra 20, 30 pounds every single day, every single step that can have a significant impact over the course of, like I said, 20, 30, 40 years.

Toree: Yeah. Now, it’s interesting living in somewhere like Michigan versus Florida, where you can kind of spend more time outside year-round in Florida. Do you see a lot more active people? I mean, because you grew up in one, and practice and have your full adulthood, I guess, in the other, is there a big difference in population of like being active and people really wanting to be able to go and hike, and go run on the beach, and be outside more?

Dr. Herrema: Yeah, I would say the patient population tends to be a little older here. Your 80 to 90-year-old here seems to be a lot healthier than your 80 to 90-year-old up in Michigan. You’re able to be more active. Of course, a lot of patients are snowbirds, where they will spend six months down here, and then six months up there. A lot of them will come down here in the winter to have their joint replaced, and they’ll go back up in May. No question, it’s a lot easier to recover here than it is up in Michigan this time of year.

Deciding if a Knee Replacement is Right for You

Toree: Yeah, I believe that. Well, thanks for hanging out with us. I’ve got one more question for you. What would advice would you give someone who’s looking into a knee replacement? And is there misinformation that they should know about or avoid somehow before making a decision?

Dr. Herrema: The biggest thing, and I kind of touched on this before, is the idea that you should wait as long as possible, and almost like suffer through it as long as possible, because you don’t want to have to worry about having a revision surgery down the road.

I’d say if it’s significantly affecting your quality of life, then I think there’s no reason to live life like that. Get your joint replaced, move on, enjoy life. If in 30 years, you end up needing something revised, well, then I think it was worth it that you were able to enjoy everything prior to that.

Toree: Yeah, absolutely. I think that’s great advice. If you’re in the Clearwater, Florida area, or you just want to take a trip down to Florida, and recover somewhere sunny, you can visit Dr. Herrema, and visit him on social media at Orthopedics Specialties of Tampa Bay, or at the website there, which is All of that information is going to be below, where you can actually find us as well at You can follow our social links.

Again, if you wanted to be a guest on our podcast, feel free to email us at [email protected].
Thanks so much, Dr. Herrema. We appreciate you taking the time to chat with us today, and lend us some of your expertise. We appreciate it.

Dr. Herrema: Thanks for having me.

Toree: Of course. All right, well, we’ll see you guys next time. Thanks a lot.

Disclaimer: The content discussed on this program is often medical in nature, and is used for informational purposes only. No content discussed should be taken as medical advice. Please consult your healthcare professional for any medical questions.

Privacy is also of the utmost importance to us. All people, places, and scenarios mentioned have been changed to protect patient confidentiality, unless given explicit written permission to share.
This podcast should not be used in any legal capacity whatsoever, including but not limited to establishing a “standard of care” in a legal sense, or as a basis for expert witness testimony.

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