Better ankle surgery

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Posted: Thursday, August 1, 2013 3:52 pm | Updated: 12:48 am, Thu Aug 22, 2013.

MINNEAPOLIS, Minn. (Ivanhoe Newswire) -- When arthritis affects the ankle simply walking can be excruciating. Fusing the ankle joint or putting in a metal implant can help, but for active patients they could wear out quickly. Now, there is a new procedure that one doctor believes has the potential to last a lifetime.

“I’ve been riding for almost 40 years now,” David Reid, ankle arthritis patient, told Ivanhoe.

Harley salesman David Reid’s put a lot of miles on his wheels, but ankle arthritis took the fun out of riding bikes.

“It was not only painful, but it would also lock up,” David told Ivanhoe.

An ankle fusion would limit his flexibility.

“Once it is fused, the motion is gone 100 percent,” Fernando Pena, MD, Orthopaedic Surgeon at University of Minnesota Physicians and Assistant Professor in the Department of Orthopaedic Surgery at the University of Minnesota, told Ivanhoe.


“You will destroy it in very, very few years,” Dr. Pena explained.

However, a new procedure Pena pioneered might last a lot longer. The doctor cut out the defective surface of David’s lower ankle joint.

“We are just removing the dome of the bone,” Dr. Pena said.

Then, he transplants bone and cartilage from a cadaver.

“We make a similar cut on the piece of the bone that we got from the cadaver and just put it in and fix it with screws,” Dr. Pena explained.

Within six weeks the transplant melded into David’s ankle.

“We have healthy bone with healthy cartilage all the way across the joint,” Dr. Pena said.

“It feels like a new ankle. I’m now taking the stairs again. It’s made just a huge difference in my life,” David said.

With a new ankle, David’s back to his old hobby.


Fernando Pena, MD, Orthopaedic Surgeon at University of Minnesota Physicians and Assistant Professor in the Department of Orthopaedic Surgery at the University of Minnesota, talks about a new approach for ankle arthritis.

If you could, tell us about this approach that you have been using for three years now?

Dr. Pena: People who develop ankle arthritis because they are too young or they are too active, their only options used to be either an ankle fusion or an ankle replacement, and they are not good options for those patients. We were still being forced to do ankle fusions, which is less than ideal, until one day I came up with an idea that is the equivalent of doing an ankle transplant, where we will be replacing half of the ankle joint with a piece of bone and cartilage from a cadaver. So, we are bringing a live tissue to the patient’s ankle and then basically swapping the defective surface from the patient with the new surface from the cadaver. We have been doing that for three years and have seen amazingly good results. There are still some questions we are trying to answer, but for the most part it has been truly fantastic results and progress. 

What kind of results do people see? Can they get back to what they were doing before they started having ankle problems?  

Dr. Pena: I am a little bit conservative in terms of selling expectations to the patients. For the most part you could build a case that there are no limitations in terms of what they can do, but what I tell them is that except for pounding activities they will be able to do anything they want to do. Probably one of the most dramatic cases that I have seen is a woman was 17 years old. She had a history of leukemia and was blasted with steroids. She had a bunch of bones dying in her body and both of her ankles suffered significantly from this. We did this procedure and when she was first presented to my clinic she was in a wheelchair and unable to walk, but now she is going to college without any type of handicap. She just got pregnant and is moving forward with life, and she is just three years out from the procedures we performed.

We hear about athletes having to get ankle fusions or other procedures and it can take away the quality of life. Why is that? What is an ankle fusion or an ankle replacement?

Dr. Pena: If we use the model I have here in my hands, the ankle joint is the one that is just at the bottom of the lower leg bone and is adjoined to allow you to move your foot up and down. We have other joints in the foot that are also going to participate in the motion of the foot itself, but when we fuse the ankle this joint gets fused. This is what people call on the street to freeze a joint and basically these two joints, or two bones, will not move from each other. If we think in very mechanical terms, which fortunately how our profession works, if this joint is not moving but you are still moving your foot every time you take a step, all the adjacent joints within the foot have to work extra hard to compensate for the lack of motion of this joint. So you are going to wear and tear these joints much faster than you would if your ankle was functional and therefore you are going to have a large amount of osteoarthritis coming your way. Once the ankle is fused it is perfectly fine, we are done and you move on, but the snowball effect that starts once we fuse the ankle is what really concerns us in regard to the patients.

If you cannot move that bone at all and it is fused, what happens?

Dr. Pena: Once this is fused this motion is gone 100%, with the procedures we are talking about we replace the top portion of this bone and maintain the motion of the ankle joint. We do not do anything to the lower leg bone and they have to meet some specific criteria to qualify for this and so forth, but once this joint is replaced the joint is basically back to square one.

With an ankle replacement are you using titanium parts or something else?

Dr. Pena: For ankle replacements there are a few models out there and they are basically made of metal; that would probably be the easiest way to describe it. With an ankle replacement what we do is replace the bottom surface of the lower leg bone, the top surface of the foot bone, and then we just square it out and put a replacement in. The best way to think of joint replacement is like a tire in the car. It has limited mileage, you can only use it for X number of cycles or whatever you want to call it, and then eventually the joint wears out. When it wears out we are faced with new problems and challenges. If I replaced an ankle in a person who is 30 years old, they will feel so good that they move up their level of activities and will completely destroy that joint in five years. Then they are 35 and now we have another problem on our hands and the whole thing starts dragging itself.

What is the kind of expectancy people should think of when they are considering a fusion or replacement?

Dr. Pena: Ankle replacements are working much better these days because we have learned a way to be more critical with patient selection. If a patient is well selected, the numbers we have now are ankle replacements lasting between 10 and 15 years. Again, that is very dependent on what patient you perform the procedure with, what type of surgeon is doing the procedure, and those types of things. An ankle fusion, once it is fused, it is fused and there is nothing else to do about it. It is more what is going to happen to the adjacent joints down from the ankle into the foot. The replacement is the one that continues bringing us some headaches and so forth afterwards.

What do you call the procedure you have been using that you kind of developed?   

Dr. Pena: The way we describe it is the implantation of a fresh osteochondral allograft, and that is basically a fancy word for a piece of bone and cartilage from a cadaver that we are going to implant into your own bone.

Allograft is dead tissue, or tissue from a cadaver; is that correct? 

Dr. Pena: Correct. Allograft is basically a piece of bone or cartilage or any type of tissue coming from a different person.

Can you explain the procedure further?

Dr. Pena: The procedure has been performed by some other people, but there are different approaches to the ankle joint. One of the things about the ankle joint is that it is a very constrained joint; so it’s very difficult to have access to the joint regardless what angle you look at it. What some people have done is cut the bone towards the outside of the ankle joint to gain access to the ankle and then work on the surface to replace and swap surfaces. What I have done is use the same approach we use for ankle replacement, which is to come from the front. It is a little bit more challenging, but for the most part it works quite well. Once we are looking at the ankle from the front, they will make a cut through the surface of the bone, pull that piece out and make a similar cut in the piece of the bone that we got from the cadaver. Then we put it in and fix it with two screws.

So you are not replacing the entire bone, you’re taking the surface of the bone? 

Dr. Pena: Correct. More importantly, we are not disturbing any other ligaments, bones, or structures within the ankle joint. We are just come from the front, grab it, swap it, and then we are done.

How big of a piece are we talking?

Dr. Pena: In terms of millimeters, we average between 8 and 10 mm. In terms of cross section, it is just the whole surface of the ankle joint.

The arthritis is really affecting that part, right?  

Dr. Pena: Correct. The arthritis for the most part is always within four to five mm from the surface. It is a series of excavations, divots, and craters that we develop through the surface, and because it is not a smooth surface anymore and there is no foundation for that cartilage to survive, people have pain.

Is it screwed in or glued in? How is the replacement made to adhere to the bone that already exists?  

Dr. Pena: We affix it with two screws, and the screws have a very specific design because obviously they have to grab a piece that is fairly thin. The screws are going to do the job for six weeks until your own body recognizes the foreign bone and then they grow together, but no metal in the body is meant to work forever. We go through cycles and there are metal failures and so forth, so it is just to hold the piece in place until they heal to each other. That for the most part happens within six weeks.

Are the screws taken out then or do they stay in?  

Dr. Pena: No, they stay in.

What is the recovery time of this procedure?  

Dr. Pena: We advertise to patients that you will be on crutches for six weeks. After that we put you to a walk with a protective device called a CAM walker; it is a big bulky plastic boot. Within another four to six weeks from that you move on without any restrictions.

So it is a 10 to 12 week recovery? How does that compare to a fusion or a replacement? 

Dr. Pena: Everybody is different and every surgeon is different, but for a fusion we advertise three months on crutches with a cast, which is a long recovery. The ankle replacement has a slightly shorter recovery because ankle replacement is very similar to the recovery from the allograft, but the advice I always give to patients is do not make a decision based on the short term recovery because we are talking about a lifelong decision. To make a lifelong decision based on two weeks here or two weeks there, I do not think it is in their best interest. 

Do you think that replacement could last a lifetime?  

Dr. Pena: We do not know yet, but we are hoping. 

Is it in studies now or is this something that you were just able to do?  

Dr. Pena: We are doing our own research and collecting data that we hope to publish soon. We have a fair number of patients and I have already presented data in different meetings internationally because I have quite a bit of awareness about this type of technology. There are two other centers in the United States that are doing a similar procedure and maybe more people are doing it as well, but they have not been reported yet. The results from these centers are as promising as ours, so I think there is another option we can develop. I will have to say it is a pretty tricky surgery to perform and it does not allow you to make any mistakes. If you make one cut that is wrong, automatically the surgery gets aborted because we do not have another piece to put on. It is quite stressful from my point of view, but if you are careful and take the proper steps, then everything works well. We have not had any issues from a technical point of view.

Who is this right for and who might it not be right for? 

Dr. Pena: We are looking for young patients with ankle arthritis, and one of the most important features is that they have to have what we call unipolar disease. Unipolar disease means that only one half of the ankle joint is affected. The moment you have arthritis on both surfaces of the joint, across the lower leg bone or the top of the foot, you are not a good candidate for this because it has already been proven it does not work well. You need to have this disease or arthritis on only one-half of the joint, ideally on the bone coming from the foot which is the most common location.

Is unipolar more common than having it on both sides?

Dr. Pena: No. It is a matter of how did you get your arthritis. If it is from regular wear and tear, you are going to get it on both surfaces. If it is from an accident or trauma, it is more likely to happen in the lower surface, but if you have it on lower surface wait long enough you are going to develop it on both sides of the joint as well. So, it probably has to be a unique cause for arthritis and it also has to be caught in relatively early stages.

Why is an ankle replacement not ideal for someone who is younger? 

Dr. Pena: They will destroy it in very few years. I always tell my patients, if I give this absolutely gorgeous high performance tire to your grandmother who goes to church on Sundays and grocery shopping once a week, that tire will last for whatever driving career she has left. If I give the same tire to a college kid who just came back for summertime, the tire will be completely worn and destroyed within those three months; they are going to drive fast, they are going to spin wheels, and they are going to break hard. Joint replacement should have a similar approach. The more we abuse that joint, the less it is going to last. Because of the type of population we are dealing with, it is more likely than not that they are going to abuse the joint and then we are going to have a big hole because we removed a good portion of bone and cartilage to replace the ankle. So, we have this big hole that we do not know what to do with and now we need to replace it again. The general rule with ankle replacements are subsequent revisions will last half of the original ankle. I have fused ankle replacements, which is a challenging surgery and it works, but again, I do not think it is the right population for that type of surgery.

Have you seen any downside to this in the people who have had it done? Are there any risks?

Dr. Pena: Historically within orthopedics we have always felt that bones and cartilage are immune privilege, which means that your immune system cannot recognize a foreign body or a foreign cartilage. I am learning that this may not be the case and we still have some research to go through so there may be some issues we can’t control where this surgery may not work 100% of the time. I have a patient who I replaced a portion of the bone and within eight months she completely pulverized it. We asked her, “do you want to try again?” and she said, “Yes please.” We did it again and there were no issues whatsoever. The third time around the first piece that came across did not get along with her body; the immune system rejected and crunched it, but I don’t know that for a fact. We are still investigating this and we are having some conversations with Boston and Mass General Hospital because they are more advanced than we are, at least in terms of the immunologic response. So we are investigating what is going on with this process, but the only downside we have is that if this fails, how are we going to fix that ankle because we are missing a piece of bone. We will find a solution, but at this point I would say that is the only downside from this procedure. 

How many of these procedures have you done?

Dr. Pena: I believe we are around 17 to 18. 

Is this something you recommend when a younger patient comes in or is it something they are asking for because they have heard it from someone else?  

Dr. Pena: For the most part people do not know about this because it is not popular enough. Granted, it is something that is not done very frequently. Even some of my own colleagues do not know that this is a possibility. So, it is rare for patients to request this type of procedure or even to inquire about this type of procedure. They will ask about a fusion or they will ask about replacement; I think that is more out there in the media and internet and whatnot, but this type of procedure is something for the most part the lay person does not know about it.

How do you think this could change ankle replacements and fusions if it catches on? 

Dr. Pena: I do not think it is going to be an earth shaking type of procedure, but I think it is going to open up an avenue for people to improve their quality of life with very little downside. To request to be able to walk in the 21st century is a pretty basic request and again, these are people who struggle to walk and cannot make it to work. They cannot be productive in society, so we are just making these people able to have a job and to enjoy life. Maybe they are not running or training for a marathon, but at least they are moving around and being more active where before they could not do it at all.

What is the age range that you are looking for again? 

Dr. Pena: I do not have a magic number or a magic range, but I would say probably anybody between a teenager and a 45-year-old person.

Can we talk about David specifically? What caused his arthritis?

Dr. Pena: I believe that his case was also a blood related disease; it was either lymphoma or leukemia. He was blasted with steroids similar to the case I described with the 17-year-old woman and then he developed in several parts of his body what is called avascular necrosis, which is basically when the bones die as a side effect from the medication he is given. Once those bones die, it is extremely difficult to bring them back to life because they are dead, they cannot maintain a repair mechanism within the body or the cartilage and basically the joint deteriorates very fast. Once it deteriorates it is like, what do we do with you? He was fortunate enough that the dead bone was only one-half of the ankle joint. Therefore, we proposed to do it and he went for it.

How bad was his arthritis? Was it hard for him to walk or was it just painful?

Dr. Pena: He was having difficulty with activities of daily living. He would struggle to walk, but being a sales person, the main struggle he had is he could not perform his job because he is walking around the showroom and would not be able to finish a day of work or do two or three days in a row. He probably would be able to tell you better than I, but the main struggle he had was he could not get through his day. Again, we are not talking about someone who would like to run three more miles per week, but when somebody tells you they cannot get through a regular day? To me it is something that is quite meaningful.

How he is doing now?

Dr. Pena: We saw him probably a month ago and as far as I know he is doing fantastic. He is extremely happy with the procedure so far. I believe that his life has changed drastically, but in his particular case this is like fixing an old car. You have an old car and you are driving 30 miles per hour and then you change tires. Now you can go 40 miles per hour but you are going to change the engine. So now that he has a good ankle, the other pains and aches in his body are going to start coming to the surface again because the ankle is not a problem. He can do more, go farther, go faster, but then something else will give.


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1 comment:

  • swr1965 posted at 6:49 pm on Thu, Aug 1, 2013.

    swr1965 Posts: 1

    So if the ankle joint and subtalar joint have already been fused, there no possible way of reversing or doing a ankle joint replacement


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