Dr. Justin Arner:
Welcome everyone. I'm Dr. Justin Arner from the University of Pittsburgh Medical Center in Pittsburgh, Pennsylvania. Today, I have the pleasure of speaking with professor Stefano Zaffagnini from the Rizzoli Institute in Bologna, Italy. Professor Zaffagnini was the senior author of the manuscript entitled “A Comparison Between Polyurethane and Collagen Meniscal Scaffold for Partial Meniscal Defects: Similar Positive Clinical Results at a Mean of 10 Years of Follow-up,” which was published in the September 2021 of Arthroscopy journal. Welcome Professor Zaffagnini and thank you for joining me!
Pr. Zaffagnini:
Thank you very much for your interest in this paper. Really, very much.
Dr. Justin Arner:
Certainly interesting. I don't have much experience with these scaffolds, but it seems like certainly you do, and you're the expert, so we're excited to talk with you about it. Can you just give us a little bit of background to how you became interested in these scaffolds and their current role in your practice?
Pr. Zaffagnini:
My experience started very, very early, in 1996, when with Rodkey and Steadman, there was developed the first European study about the CMI. So the college in meniscus implant that was the first scaffold available in the time, and we started to do this multicentric study in Europe. And from this study, I became interested in this type of device because I have very much interest in trying to save as much as we can with the meniscus or maybe to replace the meniscus when it is already been removed. And that's why I started very early and I never stopped to use these scaffolds, so actually I have now done a review of my cases and I have more than 250 CMI implanted in my life. So I probably have probably one of the best experience in the world about this.
Dr. Justin Arner:
Yeah, I think that has to be certainly the biggest experience in the world, and you mentioned, preserving anatomy. Dr. Fu taught us preserving anatomy is certainly our goal. Can you give us a brief background of your study and a summary and what it adds to the literature? You mentioned you have such an experience.
Pr. Zaffagnini:
So first of all, this paper evaluated two type of scaffolds. The first is the CMI and the second one is polyurethane, became available later in 2000. I do not remember when, but I started to use also the scaffold. This is the first study that gave the results with more than 10 years follow up of both cases. We pick up 25 cases of each group of patients, between CMI and polyurethane scaffold, and we compare. This is a retrospective study, but we matched the patient for age and sports activity and so on. We evaluated more than 10 years follow up the result of both scaffolds, and it was surprising to see that no difference about clinical or MRI or IKDC and VASS, or were found in this time, in both groups of patients. It's quite a good result for me.
Dr. Justin Arner:
Yeah, certainly. Can you tell us a little bit about the different scaffolds that you mentioned, the two you compared and a little bit about those for us that aren't as familiar and when you use maybe one or the other.
Pr. Zaffagnini:
So the CMI, and Dr. Fu has the same indication, I would say the CMI is more natural because it was the first available, but it was developed by Stedman and other group of people in U.S and is made of collagen bovine, but last year, Stryker, that was the owner of the prototype and the study and the CMI in the late years, they decided to stop the production of the CMI. Now is available only the polyurethane, that is made of polyurethane, like the valve of cardiac valve and is not natural, but is only artificial, and it can be absorbable with longer time, so it is a little bit different.
Technically speaking, I would say that the CMI, that is collagen, is a little bit more soft, and you have to be very careful in the technique. That is quite difficult, especially in the fixation part. Then the polyurethane is more spongy, and it can be easier to suit with the fixation. It is becoming easier technically speaking. This is the difference between the two scaffolds.
Dr. Justin Arner:
Your experience with the technique of that is really helpful. So can you tell us your ideal candidate and have your indications changed over the time and kind of your utilization and a little bit about your technique with these scaffolds.
Pr. Zaffagnini:
The technique has been changed during the years because we started with following the indication, run by the multicentric study and around here, we saw that the technique gives us quite good results. Therefore, we enlarged a little bit the indication and we normally start doing only the substitution of the meniscus tissue when it had already been removed before. After the meniscal was performed between maybe 2, 3, 5 years before, and to avoid the pain that this patient has, we started to implant this type of scaffold. And the same technique is uses for the actifit.
They decide to use the actifit is only in relation to the easier technique, that is technically less demanding than the CMI. The technique also has been changed during the years, because we started with the in, out, inside out technique, and we have to do incision on the middle side because we start with the medial mini open and after the 10 years become available, the lateral meniscus and the actifit instead, the polyurethane scaffold became available for medial and lateral at the same time.
But as I say, the indication for both technique is very similar and the technique instead has been changed. As I said, we start with inside out technique, but after they become available, the all inside technique, we want to avoid the incision. That can be a little bit more difficult for the return to daily life activity for both people. And so we decided to go for all inside, and at the end, now we do only all inside technique available in our end. So we normally do fixing the scaffold. And then we do a shuttling that is between the tissue of the recipient and the scaffold, and on the other way, because our indication is really a substitution of meniscectomy. So normally, most of the time is the posterior horn that has been changed and has been removed. And so we replaced this part of the menisci, and the results are really nice because we have about 85% of patients that have really good results, even to a long follow up.
Really, if you put something between the two bones, it is definitely a good help for the joint. Maybe at the beginning, they can have a little bit of more pain but the results at the end, after maybe six months are very interesting and stay for a long time. I have patients that after 10 years, still do training with soccer and so on. So it is really interesting results.
Dr. Justin Arner:
That was another question I wanted to ask you compared with allograft, some people have discussed segmental allograph transplantation, are you restricting your patients activities? Are you letting them get back to all the running, cutting activities as they perform?
Pr. Zaffagnini:
So I haven't experienced the meniscus transplantation segmental menisci transplantation, because my idea is that the indication is different. So the meniscus allograft is more indicated for really a complete removal of the meniscus and especially of the lateral side, and it is difficult to have the scaffold to replace completely the menisci, because then you will go to fail because also the tutoring of all the device completely is quite difficult. I wouldn't go for this as the tissue, that guarantee the meniscal allograph, is much more strong and more mechanically speaking, much better. For me, the indication for this type of scaffold is only for segmental substitution of meniscus. There is indication, definitely for this type of patient. I did yesterday one case of actifit, because I have to reprise an anterior horn of lateral menisci in a patient that has still the posterior horn. And it works very well. So it is quite easy for me now, it is quite easy, it takes 20 minutes to do a meniscus scaffold.
Dr. Justin Arner:
That's great. Do you have any explanations or thoughts- Is there a time when the defect becomes too large where you think that the scaffold is not appropriate?
Pr. Zaffagnini:
There is some concern when there is a completely absence of the rim the menisci. So then it has become a little bit more tough to fix the scaffold, and especially on the lateral side, on the posterior horn, the tissue can become a little bit more soft, and so it is difficult to fix the meniscus. My secret is, on the lateral side, to fix the scaffold on popliteus. For me it is one of the key points, the first that I do. Then I go back and forth and forward to fix the rest of the scaffold.
To return to your previous question about the return report for this type of scaffold. The indication is to allow to have a return to normal activity and normal working activity without having symptoms of swelling or pain, but obviously you cannot force the people to stay away from doing some sports. My suggestion to them is not to return to really cutting sports, but, sometimes I have patients that do skiing, they do running, they play tennis and so on, and this lasts for maybe 10 years. Definitely you gain some time for this type of patients that otherwise will go to a degenerative change of their joint.
Dr. Justin Arner:
Right. That's a great point. Have you noticed any issues with synovitis or any reactions? I know you have published on multiple studies and it seems like this is a fairly safe and benign implant.
Pr. Zaffagnini:
I would say that for CMI, definitely there is no issue of synovitis and so on, and I never saw anything because it is collagen bovine, and is really, maybe you can have a reabsorption of the device, slowly and you have the first two years, you have a little bit of the side of the tissue that remained there. But definitely if you go to see the MRI at 10 years, you have a result that you see a very black menisci again. So when they go slowly and the results maybe are in compliance with the rehabilitation, then the results are really interesting.
For the scaffold of polyurethane, that is completely artificial, what I can say is that, from the MRI point of view, the scaffold remained the same and they stayed there. But for me, what I can say, is that it remained a little bit less dark than the CMI. So even after 10 years, we saw the polyurethane scaffold, but the problem is related to the fact that it is polyurethane, and is not the collagen. It has remained a little bit less dark than the CMI, but the results are really the same. Even the failure are the same because we have in these series, we have a five and five patient for each group that is about 21% of failure at 10 years. That is a good, interesting results.
Dr. Justin Arner:
I wanted to ask you about that. Can you tell us a little bit about the re-operations? You know, certainly with allograft, it is common to have to do a debridement. Can you tell us about that and about your revision scenarios?
Pr. Zaffagnini:
Yes. So the patient that we have to remove, we have very few that go to TKA or uni. We have just, I think one case that received TKA or, but for the rest, we have one case of infection that probably was related to the technique and not to the scaffold. And then we have some that become failure, and because maybe you have a defect in the fixation, so be careful of this. They remain a little bit of fragment that move inside the joint, and then you have to do an arthroscopy to remove it, but after you remove the part that is mobile, then you have no problem at all. This is the complication that you, you can have. We haven't seen any synovitis as they say, or any fibrotic, so you don't have really to do mobilization because we are a little bit aggressive on rehabilitation and for one month we allow, the first week to stay in extension with brace. But after this, they are allowed to do flexion at least until 90 degrees for the first three weeks.
After the third week, I allow complete range of motion, and we allow partial, weightbearing starting from the 30 days. After 45 days, we allow complete weightbearing. So after 45 days, the patient can return to normal activity or can walk and can do some work even, so it's not so difficult on rehab, but in this case, with this type of rehab, we have good results.
Dr. Justin Arner:
I wanted to also ask you about that. That's interesting. That certainly people getting back to things quicker is always beneficial. How does that rehab compare to what you use for a typical allograft meniscal transplant? Is it a similar timeline?
Pr. Zaffagnini:
It is a similar timeline because even for my meniscus transplant, I normally do no weightbearing for 30 days and then partial weightbearing for 45 days. After I allow complete weightbearing. I do the same for both techniques, there is no difference. At the beginning, we allow this patient to do a lot of CPM machine, but now I reduce the time of CPM because in certain cases, I found that you have this patient of more swelling. I want to remove the swelling, and, you see, if you do less CPM, the patients stay better, for me. So they have to return to normal activity as soon as they can.
Dr. Justin Arner:
That's interesting about the CPM and certainly good to know. You mentioned before your trick about the implant through the popliteal tendon, can you tell us more about that? Are you typically doing that with your other allografts and your meniscal repairs? And have you found any issues with putting the implant through the pop and any other thoughts about specifications, about getting it stabilized initially in the median side?
Pr. Zaffagnini:
So the stabilization of the median side depends on the amount of defect that you have to replace with the scaffold and, about allograph, on the median side, I try to do a sort of fixation of the mini sky to avoid also the extrusion. Normally I start from the posterior part. I do my tunnel for the posterior horn. Then I introduce the meniscus allograft and I start shuttling from the back. When I arrive at the medial side, I do a small incision, and I fix with a sort of Arthrex device that allowed to have a fixation really at the rear part menisci that from the posterior horn go to the central part. There I put a point there and then I continue to do my shuttling at the anterior part.
And then I do the second tunnel for the interior horn. So my anterior horn is done at the end. In this case, I normally do all, with all inside suturing. For the meniscus scaffold it is easier because you have the posterior rim of the menisci that is left. I normally try to fix, to put the meniscus scaffold in the different that I prepare in order to have a sort of tissue on front and on back of the meniscus scaffold that we use. I can put suturing at the back between the normal tissue and the scaffold. Then I go to the front and I fix in front from the scaffold to the anterior horn of the entire tissue. Then normally, it depends on the side, but normally it takes just another all inside technique that I normally do horizontal.
So, but this depends on the capacity that you have to have a good view of the scaffold, especially on the median side, that is more difficult when you have a very tight knee. Then in this case, you can do a pie cresting of the MCL, in order to have a better view and a better capacity to working, because otherwise it can get very dark. The other side is much easier. As I say, I normally do, even for the lateral meniscus allograph, I do my posterior tunnel, then I insert the meniscus and then I fix the first of the popliteus, so I can have already an idea if my scaffold's side is perfectly matching with the recipient's. Then I continue to do my, to fix all the meniscus. This is my way to do.
For the scaffold it is the same, you have to try to have a part of tissue that stay in front and back of the scaffold in order to have. But normally my siding is about three centimeters or three, four centimeters maximum of my meniscus scaffold. This is my size normally, and I can do with three or four cm, depending. I do not do too much suturing because if you put too much suturing in the meniscus scaffold, you can have a breakage of the scaffold and then you have a loose scaffold. Then you have to start from the beginning and maybe you have to use another implant. This has become very tough and very costly. Don't use too much suturing, because otherwise you have a breakage of this scaffold.
Dr. Justin Arner:
Those are great tips. Thanks for that. Tell us your thoughts, you know, with allograft, people talk about alignment and too much cartilage wear. What are your indications and thoughts with the scaffold? Is that different than meniscal allograft?
Pr. Zaffagnini:
Yes. For both techniques, for the scaffold, I normally do not go more than three degree outer bridge, because in this case it will be really reabsorbed by the bone. If you have a grade four outerbridge, the scaffold will fail, for sure. In this case, I know that I do not do scaffold anymore, because we try to do this. We try to enlarge indication, but then we found that when we do in this case, we have a failure, so we stopped to do this type of procedure. But for the meniscus allograft, I would say that I have a great experience even in patients that are over 50 years old. Also I have just operated yesterday, I did two meniscus transplants yesterday, and they were one lady of 21 years old, she has very bad grade four on the lateral, completely grade four. What you do at 21 years old, you do a uni, never for me, never.
I have put the meniscus transplant. It was very nice and it covered the bone, because it was bone on bone, really, it was terrible. The same for the other patient that I did. 43 years old, but 43 years old in a young patient. Why you have to replace with a, with prosthesis when you have this possibility to have an implant that can maybe save the joint and the patient for more than 10 years. That for me is better. I normally do even on grade four now, for some case, if you have both changing of alignment, that is too much after. If they are more than three degree of varus on varus, I try to put also the osteotomy in varus on varus.
Dr. Justin Arner:
Excellent insight. I appreciate all their explanations. We appreciate your time today. I think we're running out of time. So thank you for speaking to us all the way from Italy and your expertise is certainly unmatched for the rest of the world. So thank you, Dr. Professor Zaffagnini, thank
Pr. Zaffagnini:
Thank you to you and thank you to Arthroscopy, and let's stay in touch
Dr. Justin Arner:
Thank you so much. Professor Zaffagnini's article titled “A Comparison Between Polyurethane and Collagen Meniscal Scaffold for Partial Meniscal Defects: Similar Positive Clinical Results at a Mean of 10 Years of Follow-up” is published in the September 2021 edition of the Arthroscopy journal, and is available online at www.arthroscopyjournal.org. Thank you for joining us.
The views expressed in this podcast do not necessarily represent the views of the Arthroscopy Association or the Arthroscopy Journal.