Doctor Joel L. Mayerson, MD, professor of orthopedic surgery, medical director of sarcoma services, the medical director of perioperative services, and the chief of the Division of Orthopedic Oncology at The Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, talks about a new prosthetic that changing lives for amputees.
Interview conducted by Ivanhoe Broadcast News in April 2022.
Could tell me a little bit about osseointegration?
DR MAYERSON: Osseointegration is a term that describes using a piece of metal and combining it with someone’s bone to integrate into a connection for a prosthesis or a prosthetic leg. Most of the time, people have a socket that is outside of their skin, and they fit it into their body somewhere like your foot goes into a shoe. We use suction or silicone to try to make sure that it fits and stays on. Osseointegration allows us to put a metal bar inside someone’s bone and then use some complex surgical procedures to try to close off the gap from the skin on the outside to the inside so that we don’t have a metal infection with a foreign body. And then, a small piece of metal can stick out of their skin. And instead of having a socket like a shoe, we can have a prosthetic leg just snap on the same way that you would snap a drill bit into a drill.
Who would benefit the most from this?
DR MAYERSON: Right now, osseointegration prosthetics or components are FDA approved for people that have challenges with standard socket wear. Sometimes people have pain from their skin getting pinched as it goes into the socket, or they have a nerve ending that gets pushed on that makes it uncomfortable and they can’t walk. So, right now, those are the people that are the ones who can benefit most. We hope that as we learn more about osseointegration and make sure that it’s safe, we can widen that spectrum of people who may benefit. But currently, those are the people that can have the surgery.
Is this technique primarily for people who’ve lost limbs to cancer?
DR MAYERSON: It’s lost limbs for many things. One, there are a couple of things that we haven’t branched out into as much, yet. People that have vascular disease and have an amputation may not be the best candidates because we don’t know if their skin is going to be viable to modify their leg to put the prosthesis in – patients that have diabetes, that probably also have vascular disease and patients that have had a prior infection. If you’ve had an infection and you put a piece of metal in, it makes it a higher risk. So, we’re more guarded on using people with a history of that, as well. But many times, if people have had an amputation from a trauma, didn’t have infection or they have cancer, they should be fine.
You’ve mentioned some of the complications that come along with wearing a prosthetic limb. Will this eliminate sores?
DR MAYERSON: Yes. There’s no contact at all with the prosthetic leg. The osseointegration prosthesis, the metal bar sticks out of the skin, has a little knob on the end that has a turnkey that you can snap it onto. So, there’s no further skin contact with the prosthetic leg.
How easy is it for the person to adjust and take his or her limb on and off with this?
DR MAYERSON: It’s very easy for them to take their prosthesis off and on. It’s as simple as if you have a drill bit and you want to tighten that down in your drill. So, they loosen it. It comes off. They tighten it. It goes on.
How do you put in the metal piece during surgery?
DR MAYERSON: People that have a standard amputation, we’ve always been taught to bring muscle over the end of each bone, that way the muscle is covering the end of the bone so it’s not sore when you put it into the socket. We have to cut the muscle off because we don’t have that need for the tissue to go back and forth. Then, once the area is open, we take and fit to make sure we have an exact fit for that bar because it has to be nice and tight. It’s actually threaded, and we screw it in. We do that in the first stage and then, we have a plastic surgery team that works with us. They do what we call a “thighplasty,” where they reduce the amount of soft tissue envelope so it’s not floppy. Then, the second stage at Ohio State is done by our plastic surgeons completely. Once the soft tissue heals, they do a second thighplasty where they take a nip and tuck and make sure it’s exactly the way they want to. And they make the opening in the skin that’s going to be where the metal bar will stick out of the skin. That’s called an aperture. So, they construct that. And then the skin has to be fashioned so that it will directly heal down to bone. Normally, there’s not many places in our body where we have skin that directly heals down to bone. And that’s what we believe prevents the infection from the metal from the outside is the skin creating an occlusive area around the bone and the metal so that it doesn’t get infected.
Is the mobility the same or better for patients?
DR MAYERSON: The patients that I’ve done so far say that it’s better and it’s also a little bit different. Normally, when they have a socket, you have to worry if the socket is going to piston back and forth. Especially if they get sweaty in the summertime, it gets loose. They say that they just don’t have good feel and that it’s a part of their body and they have to worry if it’s going to slip. So, they have to continually think if it’s going to be a problem. So, in this case, their prosthesis essentially becomes part of their bone because it’s exactly hooked. And when their bone is involved with the prosthesis, they have to learn how to walk a little differently than they did before. The prosthesis provides direct feedback because they can feel their bone moving, their bone hits the ground, they can feel that resistance against the bone. This doesn’t happen with a standard socket. It only was soft tissue in the past.
How many people stand to benefit from this kind of technology?
DR MAYERSON: There are about 1.6 million amputees in the United States and probably somewhere around a third to a half of those people have challenges with their sockets at some point in time. Not all of them have chronic problems. Sometimes they can be managed by their prosthetist and work through it. And as we talked about, not everyone who is an amputee is a candidate for this procedure. But there are certainly a large number of patients that would be a candidate for this. It certainly is in the thousands as things move forward.
Is the procedure just for lower limbs?
DR MAYERSON: Right now, it’s FDA approved for the thigh bone (femur). In the military, they’ve done research on shinbone (tibia) and arms (humerus). And they’ve had success with both of those. But as far as FDA approval for the civilian population, it’s just in the femur, currently.
Can you tell me a little bit about Broc Potts?
DR MAYERSON: Broc Potts is a long-time patient of mine. He had an osteosarcoma of his shinbone at the age of around 10. Somewhere around 20 years ago. At the time, he had an attempt at a prosthetic reconstruction. Chemotherapy hurt his immune system, and he got an infection in his prosthesis. And he made the choice with his parents to decide to have an above knee amputation at that time so he could continue with his cancer treatment. He’d been a long-time amputee. And then, as he reached his mid to late twenties, he started to have challenges with his prosthetic wear. His body size changed a little bit, his body habitus, his needs in being a dad and having a family. And his ability to work was affected significantly, that he was able no longer able to work because he just couldn’t wear a socket all day. And in follow up with me, he came to ask me, is there anything we could do so I could go back to work and be active with my children? And this is just as the osseointegration prosthesis was going through the FDA approval process. And it was about a year, I think, before it was FDA approved. We stayed in contact. And as soon as it was FDA approved, we sat down, and we were going to get started. He was a great person to start our program here at Ohio State.
When was it FDA approved?
DR MAYERSON: I think it was FDA approved in late 2020 or in 2021. It’s been about a year and a half since it was FDA approved.
Do you remember when Broc had the procedure?
DR MAYERSON: Right in the early time, I think it was December 2020 when he had his surgery.
What’s follow up like for him? How often does he have to come in? What does he have? Does he have to do anything?
DR MAYERSON: So, initially, the first stage of the surgery is done, and we see him every couple of weeks and make sure his wound is healing appropriately. About two months after his first surgery, we planned for the second stage of surgery. And then, he has another recovery from that for another couple of months. And then, people with amputees don’t bear weight through their bone so, their bone gets really soft because our bone has to bear weight and use gravity for it to remodel appropriately. So, we had to gradually increase the amount of weight bearing he had on his stem that he was beginning to weight bear on. That took a couple of months. And then, in the about six or seven months down the road from his initial first surgery, he was able to be fully weight bearing. And then I was able to be in the gym with him the first day he had his prosthesis that he was fully weight bearing. So, it was a lot of fun for me to see the process from start to initiation of finishing and see the great success he had.
What was it like watching Broc?
DR MAYERSON: I have one of the best jobs in the world. I get to see people through their cancer treatment and hopefully make them long-term survivors. And then my job also includes making them as functional as possible for the long term. So, Broc is one of the perfect examples. We made him as functional as possible with the technology we had available for many years. And when new technology became available that would help him be more functional, we made a way for him to get access to that and then to go through the process of seeing what other doctors had told me how this worked and how it was going to help the patients, getting a chance to see it live through Broc and then getting a chance to see him walk. It really is extremely satisfying and why I love my job.
Are there any trials ongoing right now for approval? I know the military is studying other uses, but are there any other trials for other parts, other limbs?
DR MAYERSON: There are a couple companies who are trying to get their device approved by the FDA. There’s only one now. It’s called the OPRA by Integrum. There are a couple of different iterations and ways that it works. I think Integrum is trying to work on getting FDA approval for the tibia and the humerus, as well. The humerus is a less common amputation site than the tibia is. The tibia is very common. The challenge with the tibia is the amputation level and the rod that sticks out gives you a much shorter version that you can walk. So, you’re not using a standard prosthesis. And it would change what’s available and make things a lot more expensive. So, they’ve got to work through the system to make that more viable.
So, it’s not a whole new prosthesis that you need. It’s just the connection system, right?
DR MAYERSON: It’s the connection device, correct. So, if someone has an above knee amputation now, the state of the art is they have a computer chip knee. That computer chip will tell them how fast they walk, when their heel strikes, etc. And if they start to fall, there’s an accelerometer that will say it’s going too fast, and it will lock their knee up, so they don’t fall. So, they get to keep that part. The only thing is the connection. Instead of a socket, it will connect to the osseointegration prosthesis.
What’s the goal of the procedure?
DR MAYERSON: That it will help with both your pain and allow you to have a functional prosthesis at whatever level amputation you have.
How far away?
DR MAYERSON: Unfortunately, too far. There are people in the military wounded – warriors that one of my colleagues here at Ohio State, Dr. Souza, has taken care of that have a Luke Skywalker arm. And they will tell you, I’m doing this. This is where their prosthesis moves as their hand normally would. And so, they’ve had a trans-humeral osseointegration prosthesis with an electrode that’s been implanted onto their nerves and able to move the prosthetic hand. The challenge is it’s now over $1,000,000 to do that surgery. So, it’s not ready for primetime with the public because insurance companies are not going to pay for it. The military obviously has a vested interest in amputation care because soldiers who lose limbs in battle need to return to normal function whenever possible. So, our goal, combining the military medicine program to apply for grants to combine research between different institutions is to see if we can bring that down in price and hopefully bring it to the masses so that people will be more functional.
Is there anything else that you would want to make sure that people know?
DR MAYERSON: There is an operation that’s called targeted muscle reinnervation. Targeted muscle reinnervation is when the nerves are cut during an amputation, the main nerve is sewn into a small motor branch. TMR allows for the repaired nerves to fire into the smaller nerve and helps prevent pain after surgery. It also helps decrease the amount of phantom pain or pain in someone’s amputated limb that they have. We know that once the nerves are cut in an above elbow amputation, there’s one nerve that brings your wrist up, another nerve that brings your wrist in your fingers down, and another nerve that allows you to bring your fingers sideways and cross. So, if you were to put those nerves in a certain place and put an electrode on someone’s skin or even under the skin, if your brain would fire that nerve, that electrode would be able to sense the nerve is firing. If you hook it up to a prosthetic limb, it could move the same direction that the hand would move when you’re doing that. So, now, the military is doing research. And someone that has a high-level amputation called a forequarter amputation where your whole arm and your shoulder blade is removed, they can take the nerves and sew them into your chest muscle. They can put an electrode on top of your skin. And when the nerves that would normally move your hand in a certain direction are fired, that electrode then transmits it to the prosthesis. And the artificial hand moves the same way that the person’s hand will move. You can do the same thing in the lower extremity for people’s foot. So, we do targeted muscle innervation in all of our cancer patients now to help them with phantom pain and pain after surgery. It also sets them up for this research, as we get more advanced and proceed, that we’ll be able to trial those electrodes on their skin and be able to potentially get them access to advanced prosthetics.
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:
Amanda Harper
(614) 685-5420
Sign up for a free weekly e-mail on Medical Breakthroughs called First to Know by clicking here
