Chapters Transcript Clinical, Functional & Radiographic Outcomes of Transfibular Total Ankle Arthroplasty at a Minimum 5-Year Follow-up Course: NYU Langone Orthopedics 2nd Paul Lapidus Foot and Ankle Symposium But I talk about the outcomes of transfibular total ankle arthroplasty. This is analysis of 251 cases with minimum 5-year follow-up. Um, I am a co-inventor of the system. I wrote the patent in 2000. Here's my other conflicts, and for those of you who don't know, it's a transfibular approach, semi-constrained, fixed bearing, ultra-high molecular weight polyethylene. It's a curved surface at every interface in the sagittal plane. There's a sal a shallow depth resection. We take the least amount of bone of all the systems, we're essentially resurfacing. The trabecular metal is uh unique. It's tantalum, it's not uh it's not titanium, and that is present at the bone implant interface. So this is a case that you could see that I'm scrolling through, that's a vari correction. That we uh did the implant on and, uh, we have been able to do uh really nice corrections with this and, um, get a really good range of motion. Our results were just published for 130 patients in JBGS last week or maybe 10 days ago, and, um, so I'm looking forward to, uh, presenting this 251 at the next meeting at the OFAS. Uh, this is what trabecular metal looks like. This is tantalum that has been, uh, heated to gaseous state and then deposited on the carbon scaffold to make this implant. This is one of Charlie's cases where the patient had an amputation for another reason, and you could see the, uh, bony ingrowth here. Uh, this was published in JBJS is spectacular, and this really does happen, um, and there's lots of studies on that. We also have a different polyethylene. And this is uh our wear testing on the polyethylene, when we looked at it versus conventional plastic with a twisting inversion E version uh stress testing, we had 5 times better wear properties than the conventional plastic. And when we used a finite element analysis to look at that plastic, we found out that it did not have any points that would lead to fracture. And I don't know of any cases where the implant has had a poly failure due to fracture, um, and, uh, I should know about it because I'm, I'm involved with the implant, but I haven't heard of any case. Um, so, this put in from the side, so, with the side approach, we peel down the fibula, we can look at the dome of the talus and do a curved cut. Again, we have a curved cut, which means we have more bone preserved, less bone resected, and increased surface area. The articular surfaces of the implant are designed to allow for 3 degrees of internal and external rotation. And uh we have, um, again, very good surface uh preservation. So we have a lot of bone, high density bone, uh, and we are also following the micro microarchitecture of the bone lines, so that we are putting in curved implant on a surface that's used to receiving curved stresses, and so that I think helps to uh keep the trabeculations doing what they're doing. We do require a frame. And that is a part of the key for success for the implant. So, this is now uh our study. So we had 251 ankles, uh, all done by me from 2012 to 2020. Um, and, uh, this is the study. Basically, we had, um, the average follow-up was 6.9 years with 5 to 12 years. Uh, average age was, uh, 60, uh, and equal male-female. Um, many post-traumatic, uh, 7, 67% was post-traumatic. We had inflammatory arthritis, 6%, and, uh, BMI, uh, 31. We, we had, uh, some smokers, we had 31% were former smokers and 7% were current smokers. We had diabetes. Uh, in, uh, in 30%. We had a history of malignancy in 40%. We had, uh, ASA scores that were pretty high. Uh, you could see ASA 3, we had 74% and ASA 2 147. Here's where our postoperative, uh, numbers, uh, which are all quite consistent with the literature, and, uh, we had really good alignment. So, both in the, uh, coronal plane alignment and in the sagittal plane, and here you could see an example of a, uh, valgus, which we corrected, and this is, um, uh, with a bone block on the in the fibula. Typically we're cutting a long oblique osteotomy. And that allows us to get our length on the fibula and straighten it from a valgus fibula to a straight fibula, and, and, uh, with this varis case, you could see I was, uh, I took this straight fibula and made it a valgusy fibula, and I think that is a a critical part to our success. And like the case we were showing uh during the uh symposium, the, uh, I didn't touch the, the media malleus on this varis case. I was able to swing it around by taking away more bone laterally in the tibia. And then I swung it around, uh, and opened up the medial clear space that way without having to do the medial malleolar osteotomy. We've had really good range of motion and, uh, our range of motion, of course, in general, with the range of motion, we have found that the, uh, the more patients have mobility before surgery, the more they're gonna have it after. But we've still been able to get patients who have zero motion. Uh, we've been able to get 15 to 20 degrees of motion. Um, some of the takedown fusions, which were not included in this study, by the way, this, this excluded patients with infections preoperatively or patients with takedown fusions. We felt those were different animals, so those are different studies that we'll be presenting, so we had um. Uh, 3.6% had one, periprosthetic cyst, most commonly located about the posterior tailor component, zone 12. So there's 12 zones that you see in this picture here, mapping out the, uh, lateral view, and we could see because the implant is low profile, you could see that surface. There's nothing blocking. The interface between the bone and the metal. So, if you shoot down the rails, you should see everything. So, here's our six zones, 12356 on the tibia, and 7 through 12 on the talus, and we had uh a uh a cyst in zone 12, and we had no patients with more than 2 cysts, and 3 patients had cyst packing. Um, we did not have uh poly failure or metal failure in those patients, nor were they looking like they were vulnerable for that. But here you can see, uh, our breakdown. We did have, uh, about 20% of the cases had one zone of lucency in the 12 zones. So you'd have, like, typically like zone one or zone six would have a lucency. This is the cyst, um, and those lucencies, by the way, were not anything that were progressive. They just, I think it was an area where the bone never grew in. Uh, to begin with, but this is a, uh, a zone 6, zone, uh, lucency and a Taylor's lucency in zone 12. So we had uh 11 patient with a component revision for tibial implant subsidence. So our survivorship of this 251 was 99.6%. Most commonly the re-operation was for medial gutter debrisment, which is not uncommon in the literature with all the other ankles, but we, it was 12%. Uh, and we had isolated fibular hardware removal, uh, about, uh, 4%. We did when we went in on some of the medial malleolar gutter cleanouts, we would take out the hardware sometimes just anticipating that they may have a problem. In the earlier series of my patients. We had a bulkier, uh, fibular plate, which we, uh, changed, and that has reduced our, our level of, uh, requiring plate removal. Uh, so 4%, not too bad, but I think it's gonna be even lower, uh, in this last cluster, these last, uh, 4 or 5 years. Uh, we had, uh, 3.6% acute infections. They were patients who were at risk. They were definitely patients with multiple prior surgeries, patients who were smokers, malignancy, diabetes, ASA risk. So it was all those patients that we would stratify as being high risk. 6 required polyexchange, 3 required only IND removal of fibular hardware. And this was the survivalship rate, uh, with, uh, 99.6% retention of trabecular metal components and plastic an average of 6.7 years. We did change the plastic for the, um, infection cases, but they were not because of wear. Um, this is not unlike, um, uh, our study that we had, uh, that recently published in Foot and Ankle International with 83 ankles. Um, and this was at this uh in this study in the uh Foot and Ankle International, which you could listen on Spotify, or you could listen to pigeons playing ping pong, my son's band. I recommend that you do his, and then do mine, and then go back to his. Um, he does not talk about total ankles at all in his music. Um, but anyway, so you could check that out, but basically in this study, we had, um, pretty much the same results, except for we had no implant failures in that group. We had one in the 250. Uh, one, but none in this group. And, um, this is, uh, range of motion was the same, infection rate very low, and, uh, prom scores excellent. And then we had, uh, just recently in JBJS this, uh, 10 days ago, I alluded to our 130 cases, which had, uh, the 130, we had no implant failures in those, um, and pretty much the same results. So, uh, anyway, that's the story. What about, uh, everybody says, well, it's because Sean does it, he knows how to do this, and therefore it's a designer thing. I think that definitely helps. Um, so I will show you, uh, some other results, and this is, uh, Federico Uzweli's results, um, and he is not a designer. He's now done over 2000 of them, and basically had, um, a, uh, survival rate, sorry, he had a survival rate of, uh, Uh, the, the 97.7% survivalship after five years. This was a study, uh, at, um, at, uh, uh, HSS. Uh, Jonathan Deland was a co-inventor, and, uh, he had done, uh, a bunch of them at special surgery. Actually, I did one at special surgery as well. Um, and that guy's doing well, but the, this is his follow-up 5 years, um, and did have, uh, a survivorship of 92.5%, which is pretty good. I'm sure they are not doing as well now because otherwise, uh, Doctor D would be doing them. So I'm interested to hear, um, his, his sadness with, uh, looking at the TM ankles, but I think this is still, uh, really good numbers. And, um, and then this is the, uh, data from, um, Special surgery here. This is the uh data from the um Swedish uh registry, uh, also showing very high survivalship, um, and, uh, this is now the Australian registry which showed that the, uh, Zimmer ankle relative to the other ankles had outperformed in terms of their survivability, um, again, versus the other ankles, and there were no designers, uh, in this, uh, registry. So, uh, we're looking at, uh, patients with a, um, Sorry, let me just get to this. OK. Yeah, so people have asked me about uh uh fibular osteotomy. Do we have a problem with the fibular healing? Um, Kevin Schaeffer, a former fellow and now partner, um, he's, uh, looked at our, uh, non-union rate, and we had in 406 patients, we had 4 cases where we had non-unions, and typically we are bone grafting it and fixing it well. And, um, What about malalignment? Has that been a problem? We looked at that and we found that, uh, the malalignment, uh, severe varus deformity, a preoperative malalignment, severe varus, severe valgus doesn't seem to be a problem with outcomes. We've had excellent results with, uh, both extreme cases of varis and valgus. Uh, and now, what about, um, Young versus old, uh, last big question, this is a paper in progress. Uh, we, uh, uh, Kevin's writing this paper right now, so we looked at, um, the patients, oops, here was the young versus old. Where's my young versus old slide? OK, anyway, the young versus old slide is not here, but I thought I'd put it in. But anyway, the young versus old slide was basically looking at 55, uh, and, and, and younger, uh, and comparing that to the older patients. In the older patients, we had more cases. Of, of, uh, idiopathic arthritis and inflammatory and osteoarthritis in the younger cases, most of them were all under 55, most of them were post-traumatic and more complicated situations, greater pain level, but their numbers were better postoperatively, but we found no difference in terms of outcome, survivability of implants and complications in younger versus older patients with this implant. So, in conclusion, We feel that the study of the 251 shows that it's safe and effective, that we have very high metal and plastic component retention, and the medial gutter debrisment remains our most common reason to go back in, some with isolated fibular hardware, less than 2% fibular non-union. Deformity has been corrected and maintained, and function has improved, and the patient's uh young, as has been as good as old, and uh that's uh that's my story and I'm sticking to it. Thank you very much. Published May 10, 2025 Created by
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