Dr. Travis Decker:
Welcome to the Arthroscopy Association's Arthroscopy Journal podcast. Welcome everyone this evening. I'm Dr. Travis Decker, coming from the United States Air Force Academy and today I'm talking to both a friend and mentor of mine, Dr. Armando Vidal. Dr. Vidal is a one of a kind surgeon scientist that possesses it all. He's technically amongst the best of us, while also being able to connect with peers and patients better than most. He's an absolute orthopedic rockstar that is advancing the scientific field of sports medicine with multiple publications in arthroscopy amongst others that are helping shape our practices on a daily basis.
He's involved at every level of orthopedics from local organizations, specialty society committees and positions of leadership, along with serving on the AOS committees to help promote orthopedics and sports medicine specifically. He's a master clinician coming from Vail, Colorado, and I'm grateful to have him close by to call and learn from as it feels that his practice is a perpetual fellowship. It only gets better the further along I get, especially when I have mentors to reach out to like Dr. Vidal.
So Dr. Vidal, thank you for taking the time out of your very busy schedule, life circumstances and being willing to speak with us today.
Dr. Armando Vidal:
Thanks, Travis. This is really exciting for me. It's always fun to connect with you and thank you for that very kind and gracious introduction. I don't think I deserve it, but this should be fun to talk a little bit about meniscal deficiency and where we're going in the field. So thanks for having me. It's really an honor.
Dr. Travis Decker:
Well, I am really looking forward to this one because today we'll be talking through a technique article of yours and it's for an innovative surgical procedure to help improve healing rates and ultimately, hopefully help patients do better. So we'll talk through his technique article entitled Arthroscopic Segmental Medial Meniscus Allograft Transplant using three fixation techniques, which was published in November of 2021 in arthroscopy techniques. So let's get started. So Dr. Vidal, can you give us a brief background on the history of how you and your co-authors came to utilize this procedure and how long you've been employing this technique and the rationale behind segmental transplantation compared to simply replacing the whole thing.
Dr. Armando Vidal:
That's great, Travis. It's a great intro. So this is something that really my friend and partner, Matt Provencher, was one of the first to introduce it to me and he and I started really just kind of spit balling different ideas but the genesis really is the fact that, as you know, our solutions for meniscal deficiency are still pretty limited. Our options for meniscus repair I think are better and, I think, realized improved clinical outcomes with biologic augmentation but when those fail or meniscus is irreparable, we kind of have pretty limited options. The options for scaffolds have been promising but have kind of fizzled out. Meniscus transplantation really hasn't advanced dramatically in the past couple of decades, and we know have decent outcomes, 75 to 85% return to sport, but those are okay outcomes compared to a lot of our other sports medicine procedures and we know they're challenged by issues of shrinkage and extrusion and progressive arthritis, and those can be tough for recovery.
So I think that there's an understanding in our field that there's a need for better meniscus replacement options or ways to address meniscal deficiency and I think a lot of us are faced with a scenario where we have just a segment of meniscus that's torn. For instance, you do a meniscus repair and you do your vertical mattress sutures that we're all instructed to do and you get a radial split through one of those sutures and now you have maybe one or two radial splits and you have a segmental deficiency and you got to ask yourself, "Gosh, do I really want to replace that entire meniscus with all the challenges, the technical challenges, the clinical challenges?" So we've been thinking about this concept for a while, I think at least since 2019 when I arrived at the Steadman Clinic and probably predating that and there's some background on that.
Other people have looked at that. You look at some of the scaffold based repairs like a CMI, which is still on the market, but really limited utilization, that's a segmental replacement essentially. There have been animal studies looking at that, but we really have started thinking about is there a way that we could just replace a segment of that meniscus and what is the biomechanical consequence of that, what are the technical considerations in that scenario and I think it's still a field that's growing and our understanding of the role, where this niche fits in and what are the ways to optimize it and this is one paper just kind of reflecting our thoughts on a technique that potentially could be used in this clinical scenario.
Dr. Travis Decker:
That's an awesome background, and I know that Dr. Provencher is quite the innovator and he'll continue to push the boundaries and advance our field as you all have done up at the clinic. I think that Dr. Steadman, he really led us and has really been a thought leader in teaching us to follow in his footsteps, to pave the way for others to continue to push those boundaries and offer the betterment of the patient in hopefully improving their outcomes and then also in addition to making it technically better and more efficient for us as surgeons to do ultimately once again helping the patient. So in this specific procedure with these patients, can you go through your very specific indications for when you performed a partial meniscus transplantation?
Dr. Armando Vidal:
Yeah, so I think a lot of the indications are the same as for a meniscal allograft. So they need to be a relatively well maintained joint, so minimal arthritic change, outer bridge, zero or a one, maybe a focal area of grade two, but pretty minimal change. They need to be well aligned, they need to have a stable knee, they need to be able to comply with the post-operative rehabilitation. So they need to be essentially, meniscus deficient obviously, and ideally meniscus deficient in just one segment where they still have a posterior root and anterior root that are intact, the integrity is preserved and for the most part, the posterior horn and anterior horn are still intact. So generally, it's for a segmental deficiency around the posterior horn to mid body segment, maybe coming around a little bit anteriorly, but still the same criteria that you would use for meniscus transplant. Well-aligned, stable knee, minimal arthritic change, low BMI, able to comply with postoperative rehab.
Dr. Travis Decker:
Well, and one of the things that I read through your technique paper is that you addressed concomitant pathology at the same time, and I can imagine that especially tackling this for the first time, can you tell us through, what your experience has been? What have been the most common concomitant procedures that you are performing at this time and are you doing this in a stage fashion, so you're seeing the actual amount of deficiency or since you already have the whole meniscus there, are you kind of indicating it for segmental versus complete meniscal transplant in addition to what these other additional concomitant procedures are?
Dr. Armando Vidal:
That's a great question. I think that probably the most common clinical scenarios you'll encounter would be revision ACL with medial meniscus deficiency, right? That's a pretty common scenario. Somebody has an ACL tear, they may have a meniscus debridement or repair, the ACL fails the meniscus and the medial compartment is injured as well and you've got that deficiency. I think the second, remember maybe actually the most common scenario is somebody with medial compartment cartilage damage. I mean, we talked about they have to have minimal damage, but that just needs to be addressed, right? So they can't coexist, obviously, with a grade three lesion and do a meniscal transplant. So I would say the most common scenarios that we encounter would be that ACL revision scenario or somebody with early medial compartment damage to localized focal chondral defect with meniscus deficiency. Then they enter really into that Venn diagram of articular cartilage disorders, which is the overlap or the interplay rather of meniscal deficiency, alignment, stability, and you could argue subchondral bony status if you're choosing an articular cartilage repair strategy.
So I think as you're analyzing those either going down the paradigm and the algorithm of failed ACL or the algorithm of articular cartilage disorders, and you figure out what are the concomitant morbidities you need to address, that will drive whether or not you're going to do this in a staged or in a single stage or a dual stage fashion. So I'll give you an example. So let's say you have a patient who's got a focal chondral defect, a medial femoral condyle, segmental meniscal deficiency, embarrassed by alignment, so they really have various components of that. They've got an alignment issue, they've got a meniscus deficiency issue. Maybe they've got a subchondral boney issue, let's say for argument's sake, their stability is normal. This is a patient that's going to, in my opinion, get an osteotomy, an articular cartilage graft, and obviously we won't go down that rabbit hole of different articular cartilage repair strategies and you could argue to perform a meniscal transplant in that setting.
So I think that those cases become challenging because you're doing so much work on the medial side. So I think a lot of people would stage it, maybe do the osteotomy first, get that to heal, and then come back and do the articular cartilage work and the meniscus transplant. That'd be very reasonable. It's a lot of work on the medial side of the tibia and the medial side of the joint. You could do those all concomitantly, but then it gets challenging in terms of your tunnels. You have an osteotomy, it's opening wedge, most likely you've got screws in the proximal tibia. Now you have tunnels that are trans osseous to anchor your, either meniscus transplant or your segmental meniscus. So I think that those are the two common scenarios, failed ACL with a medial meniscus deficiency or articular cartilage with meniscus deficiency and the need to stage is really based on what other procedures you're doing and your comfort level mixing those procedures and I tell our fellows all the time, you don't need to be a hero. You don't need to do it all in one stage.
It's very reasonable to lay the foundation, do an osteotomy, get that to heal and then come back and do your joint preservation work later. It's easier sometimes for the patient, although it's two recoveries, but it's less surgery, less risk of complication, fewer moving parts. So I think that the decision to stage or not stage is really individual based on your skillset, the number of procedures you're performing, your skill, your comfort level with those procedures and how they interplay with each other.
Dr. Travis Decker:
As always, very thoughtful in how you approach, I mean even staging it. Now, going through and looking at the original technique that you guys described, can you take us through what your current technique is? Have there been any modifications made since you all published this and maybe a couple key takeaways, pearls and pitfalls on how to get this procedure just right.
Dr. Armando Vidal:
Well, I think it hasn't changed dramatically. We don't do these with a ton of frequency, so we don't have various iterations. For instance, ACL you can do hundreds in a year. Meniscal transplant or even a segmental meniscal transplant, you're doing a handful in a year, even in a high volume and joint preservation practice. So it hasn't changed dramatically.
I think that if you look at that technique, the trans-osseus aspect of it, I think it's easier to employ sometimes than some other trans-osseous procedures we do because you're usually at the mid body segment, so you're at the more open side of the joint, for lack of better term but using those trans-ossues tunnels and using root repair guides, you can prepare the meniscus, transplant, the segment on the back table and then deliver it using those holes and that really sinks it into place and then after that occurs, it's just a meniscus repair and essentially it's your typical vertical meniscal capsular repair that, as you saw in that paper, is using a traditional inside out approach with some sort of retractor, like a Henning retractor and a suture passing device and then repairing the radial splits that you've essentially created on either side of the segment.
So it's pretty straightforward in that setting. We actually did a biomechanical paper probably a few months before we did our technique paper and looked at that, and it's unclear that at least at time 0.0 in a biomechanical model that you need to add the trans-osseus sutures. I do think from a practical standpoint, it makes it easier to reduce it and control it, it's not floating around in the joint. So I think from a practical standpoint, it makes sense and it's very stable when you do that.
It's unclear though, it's actually interesting. If you create a segmental deficiency, you're essentially creating a total menisectomy from a biomechanical standpoint but if you do a segmental meniscus transplant, at least at time 0.0, you restore it to normal. So we know conceptually it works, in animal studies it works as well. It's unclear what that's going to do in the clinical scenario. Does it take, does it heal? Does it heal the bone, does it heal along the radial split? Does it heal the meniscal capsular junction? So I think a lot of work needs to be done, but in short, the technique hasn't really changed that much. It's really a meniscus repair at the end of the day, radial splits, a meniscal capsule repair and the trans-osseus part, I think from a practical standpoint, just makes it easier to control it and reduce it.
Dr. Travis Decker:
It. Well actually that leads right into the next question that I had based off of the trans tibial tunnels. This probably could easily go down a rabbit hole of the utilization of tibial tunnels for mid body repairs. I know that Dr. Laprade has published on this and his techniques and so a couple questions for you and just for the audience and do you feel that the use of trans tibial tunnels, whether it's through this technique and since we're talking about that paper and this technique, that it could possibly over constrain the construct? Are you utilizing the tunnels to specifically promote healing or provide stability to the graft and then lastly, are you always drilling from the ipsilateral face of the tibia?
Dr. Armando Vidal:
So yeah, a lot of questions there. So I think that the first question, can it over constrain? I think it can, and I think that it's probably a bigger deal on the lateral side than the medial side, right, because we know the lateral meniscus has quite a bit more excursion and I think even inside out can constrain a lateral meniscus. I mean, the lateral meniscus is meant to move 11 millimeters or so. The medial side moves less as we know, three to four millimeters, but it can still over constrain. It's still meant to move. So I do worry about that. We've been playing both bio-mechanically and clinically with variations on that centralization stitch that you referred to where we do like more of a meniscal capsular, like meniscal tibial rather repair. There's some early evidence the guys at Mayo and others have looked at, maybe these patients get a meniscal tibial ligament injury first in the setting of a root tear, I should say.
That creates meniscal extrusion, meniscal extrusion maybe put stress across the root. That's the precursor to root tears and then the root fails, and we all know that clinical scenario, so we've actually gone to more meniscal tibial based repairs. It doesn't over constrain it as much, in my opinion. It's also easier to implement, so you're not drilling through the articular cartilage and I think that's an evolving concept really. I think that there's still a lot to be determined, but I think that it's a good question, which is the centralization of some sort reduced meniscal extrusion, it seems bio-mechanically, it probably does and we know that meniscal persistent, meniscal extrusion after a root repair, for instance, which is in far more common clinical scenarios, it's fairly typical and we know that an extruded meniscus doesn't function like a normal meniscus. So I think a lot still to learn there. What were your other questions specifically, Travis?
Dr. Travis Decker:
Yeah, the second question was, do you feel that the tunnels technically, and I know you said that it makes it easier to reduce, does it provide stability to the graft which then actually helps promote healing or are you using the tunnels themselves to deliver almost like marrow elements to help promote healing?
Dr. Armando Vidal:
I think it's really the former, I think it probably does provide stability. I mean, it has to. I mean, you're anchoring it down to bone. I don't think it's necessarily so important for the healing part because you really are attaching the meniscus to a point in the tibia that's not naturally attached to. It clearly is more stable because it's anchored down. It's not free floating around but again, when we looked at it bio-mechanically, it didn't make a huge difference. So for me, it's more of a practical perspective. I don't think in these patients I'm always going to either add marrow venting or I'm going to add some sort of biologic to augment healing. So I think that in short, I think it's more of a practical thing to stabilize the graft. In terms of where you drill from, most of these are medial, I would say. In general, I like to have my fixation on the inter medial tibia.
So if it's a medial compartment, if it's lateral compartment, which I actually haven't done one clinically in the lateral compartment, I would probably drill from the contralateral compartment. So meaning I would come across the tibia just so I could have my fixation on the inter medial tibia just because on the lateral side, the anatomy's a little bit steeper for lack of a better term in terms of getting guides and you also obviously have the tibial anterior, which is covering it, which you need to contend with. So in general, I like my drills to come in from the intra medial side.
Dr. Travis Decker:
And so the role for biologics, I know you said you mentioned notch marrow venting. Have you done any other biologic adjuncts to help promote healing in the setting of these segmental repairs?
Dr. Armando Vidal:
Yeah, so I mean I think that pretty routinely we'll use a biologic augment for any meniscus repair, whether it's traditional meniscus repair or some sort of meniscus reconstruction like a transplant or segmental transplant. I think marrow venting shows a lot of promise. Dr. Laprade, when he was here Bale at published on that, showing a significant reduction in re-tear at the two-year mark. I would argue that we probably need more time to understand if that is maintained. That's something we learned in our moon group with our ACLs, is that meniscus re-tear progresses across the time continuum. So we probably need more data to know if that procedure really is tried and true and durable. We use PRP pretty frequently. I think that's probably where the best evidence is for an external adjuvant biologic. Dave Flanagan and the group at Ohio State published on that and with significant reductions in re-tears, a mixed group of different types of meniscus repairs, including roots but I think they hold promise.
I think conceptually they make sense, at least early non-randomized, non prospective clinical studies show promise, again, probably worthy of further investigation in a prospective randomized way. We're looking at the differences in outcome, if there're any, between our marrow venting and our PRP patients obviously there's cost considerations for PRP, there's practicality. Marrow venting is great, it's cheap, it's the patient's own cells, it's really readily available. I think every arthroscopic OR in the world has a steadmanol. So I think a lot to learn but in short, we do use biologics pretty liberally either in the form of marrow venting or if it's an external adjuvant, it'll be PRP.
Dr. Travis Decker:
Well, one of the most impactful questions that I have for you is I had a meniscus transplant just the other day in a very high-end, high-functioning person. Do you place any restrictions on your patients that are different in a segmental transplantation versus a complete transplantation of the meniscus? Essentially, how do you counsel, I know you're dealing with patients that love hiking, running, skiing, returning to cutting pivoting sports, so with your patients and your experience, how are you counseling them and do you put them on any permanent restrictions?
Dr. Armando Vidal:
That is a great question, and I think if you ask three surgeons, you get five different answers and some people are really restrictive and to me that kind of defeats the purpose of doing these procedures in the first place. Most of these patients are doing these procedures because they want some restoration and function. Obviously a lot of them have daily living pain, but they want some element of fitness and recreation and quality of life. So my philosophy is I ultimately don't want to restrict any of my joint preservation procedures when they are finally cleared, whether that's an osteotomy, a cartilage graft, a meniscus transplant, whatever else goes into the mix. So I actually don't put any arbitrary parameters around their knee. I tell them, and I counsel them that my expectation is that they're probably going to be imperfect in a way that I can't predict that they're going to still have symptoms.
I think it's hard to go through these procedures and not have an awareness that this was the knee that was operated on. I tell them, it's hard for me to predict what it is. I think that their knee will be better. I think they will notice an improvement in their envelope of function, but I don't know what the governor is going to be on where they ultimately get, and I don't want to be the one that sets that parameter. So ultimately, my meniscus transplants, my cartilage graftss, et cetera, don't have arbitrary restrictions with the exception of for meniscus transplants, I don't like them to do heavy load in deep flexion because the loads are so much higher across the meniscus transplant and deflection. So you do get patients who are Cross Fitters or weightlifters who like to lift at heavy loads and go below parallel, that concerns me.
In order to understand this better, actually, years ago, and I have a pretty big Cross Fit patient population, I went through all the data on what does it mean to go below parallel in terms of joint biomechanics, and in short, I couldn't find anything that showed me that squatting below parallel had any meaningful impact on a healthy joint. There's not a lot about an unhealthy joint, but we know what happens to meniscus loads but correspondingly, there's also no clear cut benefit from a strength and conditioning standpoint. At least that's my interpretation of the literature. So I tell patients, you can do whatever you want, but I think you shouldn't be squatting at load doing other fitness activities or weightlifting that takes you into those deflection angles because it's just a hedge on your bet. I don't think that they need it for strength and conditioning purposes based on my understanding of literature, and they probably are going to significantly increase loads across that transplant.
The other thing I tell patients is I have an expectation that I'll probably be going back into that knee at some point over the first decade. Actually, Matt Provencher has got a great term for it, he says they're going to need to tune up, and he's right. A lot of these patients get re-operations for scar tissue, for meniscus re-tear, for a loose suture for something over the course of a decade. So I set the stage that my expectation is they're going to have some scope or some intervention over the course of the next decade if they have a meniscus transplant. I think that generally holds true.
Dr. Travis Decker:
Time to return to running, what's your typical protocol for those folks?
Dr. Armando Vidal:
I think for broad strokes, I'd say first six weeks is non-weightbearing, it's the protection phase. The second phase, the second six weeks, week seven through 12 is this restoration of ADLs. That's all I care about. Getting them back to walking, to working, to driving to navigating stairs. By three months, my expectation is their ADLs are pretty good. I spend months four, five, and six rebuilding their cardiovascular engine with non-impact cardio, no running, no jumping, no cutting or pivoting the bike, the elliptical swimming, weight training, bar, working on rebuilding the leg from a strength standpoint and their body from a cardiovascular standpoint. Six months I'll allow them to start adding impact. How they transition into impact can vary. If they have access to ultra G, it's great because we can increase the load with running by percent body weight, but essentially it's six months, months seven through 12 really is restoration of their envelope of function where I start to lift restrictions and let them impact and run and jump and lift more heavily with the expectation that this is a year recovery.
Dr. Travis Decker:
Gotcha. Well, Dr. Vidal, I appreciate all you've done for me and for this podcast. I think that you've enlightened us and really helped us see how you think about this process, how you think about the meniscus in general, but specifically with these segmental transplantations. I think one of the things that we realized, and through Dr. Anaski and all that, the issue with revascularization of the meniscus and the limited vascularity of even the native meniscus, do you think there's any advances technically or on the horizon that may promote better healing and ultimately better outcomes for these folks and in the end of all... Yeah, go ahead.
Dr. Armando Vidal:
No, I was going to say, you know what's fascinating to me about that, we know how limited the vascularity of that structure is. Universally, meniscus transplants heal so well to the meniscal capsular junction. It's wild. It's beautiful. If you go back in with a meniscus transplant, that meniscal capsular junction looks beautiful. In fact, if they get a re-tear, it's usually through a suture, maybe a central split. I think there are always opportunities for advancement, for increased vascularity, bone incorporation, fibroblast infiltrations, things that are well above my understanding and intellect but it is remarkable how well these graphs do heal to the meniscal capsular junction, despite what we know is a challenging biologic environment.
Dr. Travis Decker:
Well, and as I end every one of my podcasts, thoughts on where research is heading as it comes to salvaging the meniscus and meniscus prepared techniques and technology?
Dr. Armando Vidal:
I think it's a great question. I'm sure this probably changes monthly for people. I think biologic augmentation is still high on the list. I think that the biomechanics of fixing menisci, I think we've gotten really good at it. I think inside out is still a really great technique. I think our all inside techniques are good, so biologic augmentation is key. I still think the holy grail would be some sort of scaffold based meniscus replacement or transplant or reconstruction. The CMI held promise. It's still unclear the clinical benefit. I think that something along those lines, ultimately some sort of scaffold that could be embedded almost like a Macy with somebody's autogenous cells that could reconstruct a meniscus. We know the meniscus is the key to normal joint, to normal knee function. There is no question. That is, to me, I tell our fellows all the time, and we're doing an ACL with meniscus repair, the most important thing we did was repair the meniscus rather than what we did to the ACL, but I think that's where we're headed.
Biologic augmentation, scaffolds, maybe scaffolds that have a cellular basis to them, but I think that that's really where articular cartilage is heading too, but I think that's where we hold the most promise.
Dr. Travis Decker:
Dr. Vidal, I can't thank you enough for joining us this evening and taking us through your article and your thought process as you approach these very difficult pathologies and so this was an article that was published in Arthroscopy Techniques entitled Arthroscopic Segmental Media Meniscus Allograft Transplant, using three fixation techniques that was published in November of 2021, and it can be accessed at www.arthroscopyjournal.org.
Dr. Armando Vidal:
Thanks, Travis. That was really fun. I really appreciate it. Thanks for inviting me.
Dr. Travis Decker:
The views expressed in this podcast do not necessarily represent the views of the Arthroscopy Association or the Arthroscopy Journal and are not meant to be treatment recommendations for individual patient.
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