So I'll talk about cell-based cartilage repair in 2021. And we have a bunch of different things. We have an increasing number of cartilage repair options while I would say 15 years ago this was an even shorter list. And a lot of that comes from allograft tissue, but you'll hear more about that later. So of all the lists, the only two really, or three I want to focus on are the particularly cartilage allograft, then a little shout out to viable cartilage allograft. These are all awkward terms because we can't use the actual names. And then MACI. So what is cell-based therapy? And the distinction is important because I'm talking about cell-based therapy. Later on, you'll hear about osteochondral procedures and they are completely different. Because cell-based therapy is like watching grass grow. It takes forever and a day. And that's true for microfracture. It's true for anything where you start with a soft tissue that then matures over time. And these are second look arthroscopies at two months after patella ACI and the tissue looks really like a wound. It's vascularized. It's underfilled. It's very soft and friable. This next one was 10 months after an ACI. This was in a condyle. Then it's almost completely filled. Condyles fill comparatively quickly. Central trochlea takes a lot longer. But now it starts looking a little bit more like cartilage. At this point, it shouldn't be vascularized. If you see vascularization at this point, it's failed because cartilage doesn't have any blood vessels. So if it's still there at 10 months, it's not going to go. And then at 24 months, if this is a successful case, it should look pretty much like cartilage. It's also the same thickness, the same consistency, peripheral integration. But this takes a long time. And that's why what Dr. Frank had mentioned before, protection and rehab is really important. And I tell patients, this is like growing grass in your back lawn. You will not set your kids free on new lawn to play soccer after two months. They'll just chew it up. And that's exactly the same thing for cell-based therapy. So you need to be patient with these, unfortunately. It's not fire and forget. So talking about PJEG, first particular juvenile allograft cartilage, it is hyaline cartilage, but it's morselized. So this is not what companies initially had told us, oh, just build the osteocondyl allograft code because it's a cartilage allograft. It's a completely different mechanism. Yes, you put morselized cartilage into a defect, but it's really just a cell carrier. It's not different than taking a Macy membrane and cutting it up and putting it into a defect. It doesn't stay the way it is. It just brings chondrocytes into the defect that then grow out of the little cartilage cubes. And these are histology slides where you can see, at least in the middle one, you can see the pink original cartilage slide, and then you see evasion of chondrocytes and then they produce tissue. And again, it's like watching grass grown. So it's a cell delivery vehicle. It's very different from an osteocondyl allograft. It's cell-based, just like my microfracture or ACI. How do you indicate, or how do I indicate that in my practice? If I have a focal-contained defect smaller than, let's say, four is already stretching it a little bit. But I would say I use it where I used to use microfracture or micro-drilling. So smaller defects that don't seem to be indicated for an osteocondyl allograft or Macy. It seems too much in a way. So for that, I use PJEC. What's nice is it can conform to any shape, so especially patella or trochleas where osteocondyl allografts are hard. This works really well. But just like all other surface procedures, it requires intact bone. You don't put a new carpet on a crappy foundation that's crumbling. That's not going to work. So good is you don't have to mess with intact bone as you would with an osteocondyl allograft or autograft. Bad is you do need good bone. I also use it frequently as an adjuvant for OCAs. So for example, somebody had failed a microfracture in the chondyle, has cysts. So I'll revise that with an osteocondyl allograft. And then they also have a little ding in the patella where I don't want to use an osteocondyl allograft. Ordering Macy seems too much. So that's a good option that you can use concurrently, and it's pretty easy because it's almost off the shelf. As a technique, there are two. This is the old one. That's where you prepare the defect. This is a patient who had a prior failed microfracture in the patella. That's that little red area that you can see in the second picture. That's one of the issues with microfracture. It messes with the bone. Then you make a little tinfoil template. You bring the particulates into the tinfoil, mix it with fiberglue, wait, and then you glue that into the defect, which is what I've been done for years now, is you just put some fiberglue into the defect, then put the little pieces into the defect, and they're moist so they stick even if it's not horizontal. Then you add fiberglue, mix it in the defect, and sort of have gentle thumb pressure. It's much easier, and it works just as well. I'm not going to read all this, but five to seven years ago, I would have said, you know, there are a few small case series, but now we have larger case series. There's no randomized trial, and I doubt there ever will be one because no one will pay for that, but at least now I'm satisfied that this actually works. When it came to the market, it came to the market before there was any publication, nothing, because it's allograft tissue. At the time, you didn't need to prove that it actually works before you can sell it, but luckily with this one, we got lucky, and it seems to work. The issues I talked about, the prolonged rehab of all of these, unfortunately, we've become more comfortable, so we have accelerated many of these rehab protocols, including MACI. It used to be three months, non-weight-bearing, and CPM forever, and now we don't really do that anymore. Hypertrophy is still an issue, especially with patella defects. There's just a lot of shear. Sometimes these patients develop catching and popping, and you go in, do a chondroplasty, and that helps. Limited data, it's improving. I think overall, the biggest issue with this, and you've heard it before for the micronized cartilage, there's no insurance coverage for this, so if you decide to do this, you eat the cost. I'm lucky at HSS, they don't notice or they don't care, but if it's your own surgery center, you will notice because this can cost anywhere between $4,000 and $7,000 per vial. It's a little painful if you do this out of the goodness of your heart. The only thing you can charge is a chondroplasty code. You can try and do a peer-to-peer, depending on how much time you have, be my guest, but most insurance companies name this in their medical policies for cartilage repair as being excluded. This viable cartilage allograft is a new alternative to that. There's absolutely no data on it because it's pretty recent. What's nice about this is you can pre-mix it. It turns into this putty that sticks. You don't really need to use fiber and glue. I want this really, really to work because the handling characteristics are so good. It makes it so easy. For me, that's not a first-line treatment because I just don't have the data, but it's certainly something I keep my eye on it. It's very similar to the P-Jack we just talked about. It's just thinner slivers of cartilage, and like I mentioned, it's this putty-like consistency that's self-sticking. Then I want to spend a little bit of time with Macy, not only because I've used that for 15 years, but because it's also, I think, among all the cartilage repair techniques, the one that has the most data. It doesn't mean that it's perfect by any means, unfortunately, and I certainly see my share of failures. That's the frustrating part about cartilage repair, that many of these things have anywhere between a 15% to 25% failure rate. I've heard for many years in my career, why do you guys even bother? I would never do anything that has a 25% failure rate until studies came out that showed that if you're a 17-year-old girl going back to soccer, all of a sudden, your ACL actually also has a 20% to 25% failure rate. I feel slightly better, and I don't do young ACLs. What is ACI? This is an autologous condocyte culture. It's a two-stage procedure that is one of the downsides. It's cell-based repair, so it shares the same slow maturation process, and it used to be a complete pain in the ass because you had to use periosteum that you would suture. It's like working with wet Kleenex, and halfway through, you would get a rip and swear you'll never do this again, which is an explanation why it's not very common. It seems to have gained traction over the last four to five years because the current iteration called MACI got approved, and this is much easier. Now you get the cells already on a sponge. That's a little bit more resilient. You can glue it into place. They're little cookie cutters, so you don't have to cut it by hand anymore. It's made it technically a lot easier and more accessible, I think, for many of us. The indications remain the same, so focal contain defects larger than two. It's not that it wouldn't work in small defects. It's just insurance companies have a minimum of two, some 2.5 square centimeters, so when you do your first arthroscopy and chondroplasty, don't dictate that it's 1.8. You just shot yourself in the foot and bought a peer-to-peer. Find a little extra area so that you can make it two. It's indicated for multiple defects, and now you can use it anywhere in the knee. It used to be not approved in the patella, but United recently was, I think, the last one that now allows patella defects. It also requires intact subcoronal bonds, so if someone has bad foundation, again, I don't use MACI. The only exception would be an OCD lesion in a really young patient. That works fine. Anything works fine in young patients, I think, except ACLs. So how do you do it? Just like microfracture, you outline the defect. You include all softened fissured cartilage. This is a microfracture preparation. All of these are exactly the same preparation of the defect. Try not to be overly vigorous when you debride your calcified layer. You don't want the whole bed to bleed for two reasons. One is because you irritate the bones, so it forms intralesional osteophytes. It's an issue with microfracture, but it's an issue with ACI if you scrape too hard. And then also you get more blood. Blood brings in a mixed cell population, and those cells are confused. They don't know what they want to become. They don't necessarily become cartilage. They can become fibrous tissue as well. This is a lateral trochlear OCD lesion in a younger kid, but it had actually detached prior. It tried to repair, but it didn't really heal. So you size the membrane. You shape the membrane. This was a freehand, and that's one of the advantages. If you have crazy geometry, you can make this any shape you want. You're not beholden to the OCA everything is round issue. And then you can glue the membrane into place. Sometimes if it's really large or partially uncontained, I add sutures as we did in the old days, but you don't have to anymore. The results, again, I won't bore you too much with this, but like most things we do, 80 to 85% success rate, but it takes a while for patients to get better. The pros and cons, any size and shape. So again, it makes it really easy in the patellofemoral joint and in the PFJ. That's my go-to. You don't compromise the healthy bone, and we have lots of data. One of the nice things about MACI is that you can do it more minimally invasive. We always used to show, and my ex-part, Dr. Minus, was famous for that, like two foot long incisions. You saw the whole distal femur. Certainly makes it very easy, but with a new technique, you don't need that anymore. You can do it through very small incisions, or, and that's what I do for tibial plateaus, you can do it arthroscopically, which initially is a little fuzzy, but you get the hang of it. So how do I decide between those two? Because that's probably the most interesting thing. If we look at insurance coverage, like I said, if you are in an environment where your institution doesn't care about the cost, and you're okay doing a mini open procedure and get reimbursed a chondroplasty code, then you could do the particular juvenile cartilage. Otherwise, MACI, you actually get paid for. You still have to do peer-to-peer sometimes, but it's rare these days. If single-stage versus two-stage is an issue, PJEC wins that, because that's a single-stage procedure. I have two young kids, early teens, who have patellar lesions, who I might have wanted to do MACI, but with summer, and then school coming soon, and everyone's going back in person, this is the first time they can go to camp, there wasn't enough time to do all that. So, they're getting PJEC. If parents ask you, well, how is my kid going to do in 15 or 20 years, that's MACI, because I don't know about PJEC, but I do know about MACI. And then last but not least, if you have a concurrent procedure where you do something else, in this case, an osteoclonal allograft, which I use frequently, then trying to grow MACI for the same day that you may or may not get an OCA, that's a little stressful, so for that, it's PJEC. In summary, cell-based procedures are viable options. Like I said, I don't use microfracture very much in my practice anymore, and PJEC has allowed me to switch from microfracture to something that's not as involved as MACI. They do need intact subclonal bone. You could bone graft at the same time and put one of these on top, but there are a lot of moving parts, so for that, I usually go to an osteoclonal option. The PJEC I use for the small and medium-sized defects, MACI for the larger one, and both share the long rehab, because this really takes a while to get better. So going back to running, especially jumping, that's a year, and patients need to know that. As Aaron had said, setting expectations is really key for all of these. And with that, I thank you, and Aaron, if you have any questions, or you. Any questions for Dr. Gamal? You kind of gave some real-life advice and tips in there to avoid peer-to-peer. I think we all enjoy our peer-to-peer education sessions. We often offer CME at the end of the peer-to-peer call for those individuals on the other end of the phone. So you mentioned documentation of size. What are some other pearls that the surgeons in the audience can take home today to try to avoid the peer-to-peer process? To avoid the peer-to-peer? So bipolar defects and meniscus status is probably the two things that are an issue. And I definitely don't want to encourage you to lie, but we can fudge things a little bit. So if there's one defect with United that used to be a big problem, that patella lesions for them was just not a thing. Patella is not a weight-bearing part of the knee. That's what the medical policy said. So clearly it doesn't need any cartilage repair. So in that case, if you find a medial femoral condyle lesion that's two square centimeters and a trochlea that's, sorry, a patella that's four, then I would just mention that the patella cartilage is a little damaged and you'll look at it, but I wouldn't talk too much about it and instead focus on something that's clearly on policy. And the same goes for bipolar lesions. Now I don't know about you, but bipolar lesions in the tibiofemoral joint, for me that's concerning, if I have a tibial lesion, that's really more advanced that I like to unload that more than going in with cartilage repair on the tibia. But bipolar lesions in the patella femoral joint, trochlea and patella, that's pretty common. And those actually do well and we have multiple studies that show that the outcomes of bipolar, Macy, for example, is not that different from unipolar, especially if you unload it with a TTO. And I think the one tip is if you have these bipolar lesions, then really just have your up notes focused on one and don't talk too much about the other one. Do the other one and feel good about it because you have literature support, but don't put the insurance company's nose directly on that. And then meniscal status, if you think it needs a meniscus transplant, go ahead, do it. Many of the medical policies now allow concurrent treatment. If you don't do it, then at least document that you have more than a functional five millimeter continuous rim because that's what they're looking for. I guess another thing, if you're trying to avoid peer-to-peer and trying to avoid denials, whichever your major insurance company is, just look up, it'll be on the website, what their actually medical policy is. Because when you first start out, you're gonna miss things that you're going, well, who would do that? You have to say that they don't have infection, cancer, osteoarthritis or inflammatory disease. You have to say that they're not allergic to genomicin and bovine products. You have to say they've been limited to two or more activities. There's a lot of little things that you're going, well, I wouldn't operate on if they had these things. Well, you just got to put it in your little template. So I just have a template, I just go down the little template, fill in all the boxes so the eighth grader who's reading it will understand. And speaking of, so disabling knee pain, I hate calling a patient disabled, I don't want to do disability, I don't want to get into that. But insurance companies will look for that. And actually, if you look up the definition of disabling knee pain, it just needs to keep you from doing certain activities that otherwise you would do. And I think we're doing cartilage repair or most procedures because people can't do certain things. So disabling sounds big, but it's really, if you choose not to do your favorite sport, then in a way you have disabling knee pain. So you can use that word, they're looking for that as well. I would just echo, especially what Jack just said, so we have a dot phrase that is specific to our main insurers, and it says patient's BMI, alignment status, ligament status, meniscus status, and then describes the cartilage defect with those buzzwords. And then we also state the patient is free of diabetes, no allergies, all the things Jack just mentioned. I'm going to hate that I'm about to say this, but our peer-to-peer rate for all of my cartilage is about 5%. It's about 1 in 20 we have to do it, which for me is better than when I first started in practice and I do it much more frequently. But it's because those things that, like Jack said, you'd never think of, I bet half the people in this room are like, I would never operate on someone like that. The insurance company, they have no idea. They just need to check their box. They have no concept of what you're doing and why you're doing it, and quite frankly they don't care. They obviously get paid more to deny. So having that dot phrase has made this so simple because we don't have to think about it anymore. I also, we don't in any of my notes ever use the word degenerative. Even if it's a degenerative lesion, we use other descriptors because when they search your note and when they, especially for meniscus, but even for cartilage, if they find the word degenerative, that just might signal a peer-to-peer because you're not supposed to do a scope for degenerative meniscus tears and you're not even talking about the meniscus, but they see the word degenerative. So those don't go in my notes. For whatever reason, we find a more creative way to describe the lesion. Yeah, so be very careful if you have somebody that you're trying to eke along with conservative management and it may include HA, and when you're doing HA, you've got to have the diagnosis of a degenerative arthritis. So if you put that in, you're just trying to help the patient out, and then they'll read that, well doctor, you said it's degenerative, and then it's a big, yeah. So I would rather not do HA, just to avoid using the term arthritis. Well, that's a great discussion, so we'll move on.

cell-based cartilage repair

cartilage allograft

MACI procedure

microfracture

ACI procedure

cartilage repair stages