Victor Prisk, M.D, a board-certified orthopedic surgeon at Allegheny Health Network in Pittsburgh, Pennsylvania, talks about a new flexible toe joint replacement that is eliminating pain and keeping patients on their feet.
Interview conducted by Ivanhoe Broadcast News in January 2017.
Tell me a little bit about this mid to end-stage arthritis in the big toe. What is it called and what causes it?
Dr. Prisk: Arthritis in the big toe is typically called Hallux Rigidis meaning that the joint is rigid. Hallux is the big toe and the metatarsophalangeal joint becomes rigid and becomes very stiff. So we call it Hallux Rigidis. It comes in a number of stages as we describe it. Early stages one and two and then and three and four are the more end stages. The further you get along in the arthritis the more motion you lose the bigger your spurs get in the Osteophytes in the joint they get bigger. You get more boney impingement meaning that the bone stops the joint motion. As it progresses the pain gets worse. It gets to the point where it’s hurting not only with walking but also it hurts with any sort of motion. Sometimes it can hurt at the end of the day, it can be very painful at night, and it can keep you up at night. The pain when it goes from just being at the end ranges of motion to being like in all ranges of motion that’s when you have to start thinking about whether you’re going to do a joint replacement to keep the motion or you’re going to do a fusion to get rid of the pain completely.
What causes it?
Dr. Prisk: End-stage arthritis in the Hallux MPB joint but in the big toe joint it’s often a result of probably like an injury that occurred somewhere along the way. It can be the result rheumatological problem, it can be just from wear and tear from being a runner or a dancer or somebody who’s really on the front of their foot a lot.
That was my next question. Is it specific to certain sports or certain activities?
Dr. Prisk: I would say that the majority of people that we see this with are probably runners, because everybody has run at some point in their life. But we see it a lot in people who are on the front of their foot a lot whether it’s dance, whether it’s gymnastics, whether it’s running. Especially if you just stub your toe on your nightstand, you know, it can cause the arthritis to progress over time.
You touched on this a little bit, but I’m going to ask again. What are some of the standard treatments then when you have this pain and it just keeps getting worse? What can you do?
Dr. Prisk: Early on you start with rigid shoes more of a bit more of a rocker bottom something that prevents the motion of the joint to help reduce the pain from everyday wear and tear. Then you can go on to cortisone shots in some cases, or use an occasional anti-inflammatory medication. But you can even put carbon fiber inserts in your shoes, things like that. But over time, those things tend to have diminishing returns as the arthritis gets worse. Then you start thinking about surgical options.
What are those options?
Dr. Prisk: In the earlier stages you can go into the joint, you can clean up the joint remove spurs and allow for better motion and less impingement of the bone that causes pain. Sometimes that can work and but it’s usually a temporizing procedure and sometimes it lasts a long time, sometimes not so much. We’ve seen sometimes where that fails within a year even. Then you have to go on to other procedures and you start thinking about procedures that spare the joint motion versus ones takes away the joint motion. The ones that spare the joint motion are either doing what we call an inter-positional arthroplasty where we put in soft tissue like tendon or allograft materials to kind of make a bumper. The problem with those procedures is that they tend to lead to instability of the joint. Then you get deformity and then less function and you have shoe wear problems. Then you go on to other procedures were your cutting the bones to relieve the pressure on the joint, those can work pretty well. But again, you’re not addressing the joint cartilage which is bad and is going to continue to go bad over time. Then you start thinking about whether you do a joint replacement or a joint fusion. The fusion procedure of course takes away motion of joint that gets rid of the pain reliably but unfortunately you know, it takes away that motion that if you want to be on the ball of your foot if you’re a dancer or you’re an athlete or something. If you want good push off strength for whatever kind of activity you’re doing, it takes that out a way. Even getting into a ski boot can be hard or a high heel is difficult. The joint sparing procedures include joint replacements just like a hip or a knee but the smaller the joint gets the more pounds per square inch on that joint and the more wear and tear. This joint is very different than the other joints because it’s kind of level to the ground rather than straight up and down. You get a lot of what we call sheer forces and that can cause a lot of wear and tear on the joint implant.
Knee or hip replacement, those certainly are the larger joints. What’s different when you’re dealing with replacement in this tiny joint?
Dr. Prisk: Yeah, certainly, the further you go down whether it’s a hip and knee and ankle or now the big toe we start seeing faster wear of the implant. Because now you have more weight on that implant, it’s a smaller joint there’s more pounds per square inch and the joints start having different congruency, different biomechanics that can lead to further failure. For instance the knee is a little bit more unstable than the hip and the ankle can be much more complex than the knee in some cases. What we start to deal with is rapid wear of the implants. The implants that we’ve had in the first MPT, the big toe joint have failed pretty consistently in early times after surgery, unfortunately.
About how long will they last? I know in knees you talked about ten to twenty years.
Dr. Prisk: Right, so the five year data on most joint replacements is pretty poor, for the Hallux, for the big toe. We have been looking for different solutions there, just like the ankle isn’t as good as the knee. I mean in ten years the ankles aren’t nearly as good as the hip. We start to look into different options and don’t have any options at this point. We started to look in to different options and we have a new option at this point.
This leads to my next question. Talk to me about Cartiva that and how this is different than what you had before?
Dr. Prisk: Cartiva is a really unique idea in that it is what we call a hydrogel implant. It’s made up of a material called polyvinyl alcohol, and it’s very similar to material that would be used to make contact lenses or other surgical materials that can really hold a lot of water. Our joint cartilage typically has a good amount of water in it and that allows for the cushioning. This particular implant has the wear characteristics of our normal cartilages. It has the same kind of compressibility, tensile strength and so it can very well replace the cartilage in your joint. Without taking as much bone to put it in because it takes a very small plug of bone and you can replace that with this implant. If you were to take it out for whatever reason it doesn’t have as big a gap that you have to fill if you have to go to another surgery procedure down the road. Like the joint replacements take a lot of bone, they have a tendency to cause the bone to breakdown and they cause a lot of wear problems. These implants have been shown to not create those wear problems, in fact the implant can go under many, many, many cycles of motion without any signs of wear.
Talk to me about how the surgery is performed?
Dr. Prisk: The surgery is performed by opening up the joint from the top of the joint. We expose the head of the metatarsal, we do a little core drilling of it and then we put in the implant and it’s just basically a plug. It just kind of goes in and it almost acts just like a bumper in the joint, just like you’re cartilage would. You can feel immediate better motion. You can feel the kind of a cushion that occurs as soon as you put it in, the joint feels like it kind of just has a little bit of a bounce to it and the motion is improved pretty much right away.
Are there any people that would not be a good candidate for this? Who would be the best candidate?
Dr. Prisk: The best candidates are healthy patients without any rheumatological problems or gout and who basically have a joint that is just worn out without much deformity with regards to the positioning of the toe. If you have a big bunion where the big toe is touching the second toe a lot or where it’s going the other direction it’s like stuck up. That would be not a great case to do with the implant because it wouldn’t correct the deformity. But it’s great for anybody who has loss of cartilage with bone on bone appearance to it, it can really help give you some cushion.
Patients are not going to lose that motion. Are they able to resume the activities that they were in before?
Dr. Prisk: Well before the surgery they’re in so much pain that they often can’t do the activities they want to do. Hopefully they have a relief of their pain and majority of people do. They do have a good track record of improving motion. They can almost double the motion that you had before. We don’t expect that in all cases because there’s just some scarring from surgery but we expect to improve motion beyond what was prior.
How long does Cartiva last? Is there any indication, because I know this is newly approved but is there any indication how long you’ll have with this joint?
Dr. Prisk: We have five year data on a Cartiva implant showing that it has a 96% survival rate. There was only one patient in the study of five years that showed failure and that was just because of recurrent pain from arthritis. That person went on to an uneventful fusion. This is a much easier procedure to do a fusion after this implant then if you were to have a large implant where you have a lot of bone loss.
Could you talk to me about Logan’s case a little bit? She’s an athlete. She played softball for a long time and I guess she had some difficulty. Could you tell me a little bit more?
Dr. Prisk: Logan is an unfortunate case in a young patient who had multiple procedures for an arthritic joint, from an injury to the joint. This resulted in severe loss of motion where she had pain with just about any activity. Even at night she was having pain. We were very lucky that this implant was approved when it was because she was really at wits end. We were on the verge of doing a fusion for her. A fusion in someone her age is very less than ideal, especially being a very active athlete. We performed the Cartiva implant and she saw immediate relief of her pain.
With that fusion she would have lost motion and lost the ability to play in sports?
Dr. Prisk: She certainly wouldn’t be able to play in any sports like she was before. Could she run, could she do a few things but not have the same level of performance, certainly she probably could but it would be less than ideal for someone her age.
Could you describe what the Cartiva implant is made of that makes it a little more unique than other implants?
Dr. Prisk: The Cartiva implant is made of a poly vinyl alcohol. It’s a hydrogel so it’s very good at absorbing the water into the implant. Giving a compressible strength is very similar to our human cartilage as well as tensile strength that is very resistant to wear of the implant. The unique thing about this is that without the wear particles that can occur with other implants, you don’t get breakdown of your bone, you don’t get the implant shifting or moving, or breaking, or fragmenting, it has shown very unique wear properties.
You described it being almost like that contact lens material. Could you tell me a little bit more?
Dr. Prisk: Yeah, contact lenses, you know, hold a lot of water for permeability of oxygen. These implants have that same kind of feel to them. They’re very moist kind of spongy kind of feeling.
Is there anything I didn’t ask you that you would make sure people know?
Dr. Prisk: I think I’s probably important to know that when it comes to these implants if you do have rheumatological problem like gout or rheumatoid arthritis these aren’t going to get rid of that inflammation in the joint. It’s not going to rid of that kind of pain. You would probably be better off with a fusion in those cases. But this implant is great, if you have a fairly healthy system that’s probably most of things I’d mentioned.
Again, more men is it equal gender about forties to fifties is your typical patient.
Dr. Prisk: I would say there’s a little bit of a preponderance of females, that just because of more for footwear in the shoes there but it certainly works well in both populations.
END OF INTERVIEW
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