being here, I'd like to thank Erin for having me and the rest of the panel. We actually had a great time doing this back in 2019 and we're excited to be here doing this in person again. It's nice to see everyone. Please remember to check if you have food in your teeth. We're not on Zoom anymore. It's a different world now in 2021. I do have some disclosures relevant to this talk, but none are specific to any of the products that we'll discuss. So when you talk about microfracture, what has really changed in the last 20, 30 years? Well, first we have to understand what the problem is and the problem is cartilage pathology. And when you look at the literature, the literature shows that there are a lot of cartilage lesions in the knee. In fact, up to two thirds of patients undergoing knee arthroscopy for any reason have a cartilage defect. And this is relevant to the topic of microfracture because it's very easy when you see a cartilage defect to put some holes in it. And many surgeons do that. And the big question is, do all of these lesions need treatment, even if it's something as simple as microfracture? And the answer to that is most certainly no. When we take a step back, and Erin highlighted this quite nicely, what do the patients really want to know? I think it really boils down into these things. And this is very applicable to microfracture. If I have surgery, how long will it last? If I have surgery, can I get back to sport? Or if I do nothing, is it okay? What they really want to know is, can I live with this symptom? Can I live with my cartilage defect? Can I live with my MRI report of a cartilage defect? Or do I need that surgery? And the key is to manage expectations. And I won't spend too much time on this, but really understanding the knee joint as an organ and not just as the cartilage, not just as the bone, but as the alignment and as the ligaments and as the meniscus. And it's really even more than that, as the synovium, as the skin, as the soft tissue environment. All of those things are important to understanding if a patient's a candidate for a cartilage surgery. And we're gonna talk about all these options today, but really highlight microfracture and marrow stimulation techniques in the next 10 minutes. How do you choose? Well, it's tough. And all the things that Erin mentioned are really valid. And I think especially for that incidental defect that so many people might tend to microfracture because it's easy, you don't have to have any special instruments to do it. You have to consider all of these different factors because many of these factors are actually negative prognostic factors for microfracture. And so even if you see a defect that looks perfect for microfracture, it may not be because of its size, because of its involvement of bone, because it's not contained, et cetera. And so it's important to consider all of these factors, but in particular, defect size, location, and containment before considering a marrow stimulating procedure. When we think about microfracture, we should take a step back and think about what even happens before microfracture, and that's the palliative option for cartilage restoration, and that's simple debridement. In my practice, this is my most common cartilage surgery is a simple scope debridement. And I bet the panel would echo the same thing. This is for our in-season athletes who shoot off a loose body, who need to get back within a couple of weeks. This is for patients who are weekend warriors who have a new chondral flap, who you're not gonna go do a big cartilage restoration procedure, or even a microfracture due to the nature of the recovery. A simple surgery still has a very extensive recovery for the vast majority of these patients, particularly if we're expecting cartilage to grow in a weight-bearing lesion. So chondroplasty is really critical for these patients, I think, especially for the in-season athlete or the weekend warrior who needs to get back to their job, who wants to get back to ski season, et cetera. And a good chondroplasty is critical to doing a good microfracture. When you look at the literature regarding chondroplasty, the literature's fairly good. Patients do quite well. The big question is how long will this last, and is the lesion in a weight-bearing surface or in a shearing surface that's going to be exposed to loads that exceed their ability to tolerate those loads and thus result in pain and dysfunction? But when you look at the literature, chondroplasty actually does quite well. Well, what about microfracture? So microfracture, as we all know, produces a reparative tissue. We call it fibrocartilage, which is primarily but not exclusively composed of type I collagen. This is technically easy, but it's also easy to do poorly. This is not where you leave the room and you say to your resident, if you work with residents, poke a few holes in here. You have to do a good lesion prep for microfracture to work. Otherwise, you're just poking holes and calling it a day. It's low-cost, certainly minimally invasive. Do it arthroscopically. It can be a first-line treatment option. You don't need any special equipment. The indications are typically small lesions that are contained in all areas of the knee joint that are not kissing, meaning not bipolar. The contraindications include those lesions with symptomatic subchondral bone involvement, not just bone marrow edema. Edema is different than a bone marrow lesion. That's symptomatic, different than a subchondral cyst. But if they do have subchondral bone marrow involvement, that's symptomatic. We want to avoid a marrow-stimulating procedure exclusively. Bipolar lesions, patients with untreated malalignment and patients who will be unwilling to tolerate the rehab necessary. The rehab for a well-done microfracture in the distal aspect of the medial femoral condyle is the same, at least in my practice, as that for a very fancy osteochondral allograft. So if they're not willing to undergo that rehab with limited weight-bearing, range-of-motion progression, physical therapy, and a delayed return to sport, and arguably a longer return to sport, and that's based out of work by Aaron, then they're not gonna be a great candidate for microfracture. Techniques, critical, and this is updated since the talk from 2019 when we talked about this. There's been several publications talking about technique. And so even though we have a lot of fancy marrow, or excuse me, cartilage restoration techniques, microfracture still gets a lot of attention in the literature, and that's because it's the most commonly performed cartilage restoration surgery. So you do need to ensure that you remove the calcified cartilage. I tell my residents this is a feel and a pitch thing. So I feel it as I'm going, but I also hear different changes as I'm using my ring curette to scrape that calcified layer. And that's that feel factor. You need a stable rim of peripheral cartilage, and we can certainly argue if it's vertical or bevel, but certainly something to contain the fibrocartilage as it's filling in that pothole. And then the concept of microfracture, which is the traditional awl with mallet, versus micro-drilling. And there's actually been several recent studies talking about the benefits of micro-drilling. Why is that preferred over microfracture? Well, less heat, less action onto that bone, less risk to the subchondral plate. And so in my practice, micro-drilling has become the standard as opposed to using the traditional awl and mallet. What are the outcomes? Well, the outcomes are all over the place. When you look at the literature, return to play ranges from 44 to 83%, and Coos improvement is about 22 points. But as Erin mentioned, what does that really mean? It takes six to 12 months to improve. This is not your quick surgery, even though it's an easy surgery. This is a surgery that takes a while for that cartilage to mature. And here's the real kicker, that improvements decline. So we all love two-year outcomes. Every journal loves two-year outcomes. Two-year outcomes are phenomenal. If I could stop seeing every patient at two months, to be honest, but two years, I'd be so happy. But the problem is with microfracture, they don't do well beyond that typically. Some lesions, if it's the perfect one to 1.5 centimeter lesion, and a great area of the knee with neutral alignment, they'll do well. But most patients, after some period of time, will start to decline, and then you need an alternative solution. What are the trends in cartilage restoration? So what are we actually talking about? How many are done? Well, when you look at a private PACTOR database, this is the Pearl Diver database, you can see, and this is nearly a decade ago, but the numbers are pretty consistent now, there's a lot of cartilage surgeries done in the US, and lots of cartilage surgeries increase year over year, approximately 5%, with chondroplasty being the most common. When you look at a different database, or excuse me, a different time set in the Pearl Diver database, you can see that using the same database and using it in different ways to analyze the numbers slightly differently, you get different results. So even when you look at the literature, you might say, oh, this study shows that cartilage surgeries increasing, microfracture staying the same, or vice versa, but you really have to dive into the details, and that's what we try to do in this study. So we took ABOS data, and I got interested in this when I was learning about what the ABOS means and what it does. And so we looked at the ABOS data a few years ago, and we took data from 2003 to 2015, and we looked at all the surgeons that submit their cases. So over 3,000 surgeons submitted close to 9,000 cartilage cases, and of those, microfracture was 80%, which means eight out of every 10 cartilage surgeries performed by ABOS board-collecting surgeons was a microfracture. Interestingly, over this study period, the number of cartilage cases decreased, and microfracture saw the largest decrease in cases, whereas osteochondral autograft and allograft transplantation significantly increased. Now, why is this? Well, we think when you look at the data, and we can never prove this because we can't see the indications for surgery based on the ABOS database, but we think that as procedures went down and microfracture's the number one procedure in this database, surgeons are better recognizing that microfracture may not be the best treatment option for many of these patients because of its lack of durability, at least with current techniques, and so that may be responsible for the trends. And courses like these and discussions with colleagues really stimulate that discussion about do we have better options, which leads us to so-called microfracture plus. Microfracture plus is essentially a marrow stimulation technique that adds a scaffold. That scaffold is available through a variety of different companies. There's a lot of proprietary names to talk about microfracture plus, but essentially it's marrow stimulation with a scaffold. And this essentially, depending on the product that you use, comes off the shelf. There is a cost associated with it. So if you work at a surgery center, you will eat this cost, and there's not really a good way to charge the patient for that. So in terms of value, we have to understand, are the outcomes worth this added scaffold? This provides a scaffold over that microfracture defect, and then we typically provide a biologic with that scaffold and almost make a putty-like glue or a putty-like consistency, and then that is covered with a fibrin glue in most cases. And why do we do this? Well, we do this because the marrow-stimulated products, that vented marrow that's coming from the bone, it's full of growth factors, rich with proteins, but those growth factors and proteins don't yet know how to turn fibrocartilage into hyaline cartilage. And what we need is hyaline cartilage to fill these potholes. And so the scaffold here combined with the biologic may be that secret sauce, so to speak, to help turn that fibrocartilage coming from your own bone marrow into more of a hyaline-type product. The clinical outcomes, two years ago, I would have said are zero, but we do have some data now, and I want to share that with you. First and foremost, when we look at scaffolding, before we get to the data, this was a great paper out of Cornell by Lisa Fortier, and they actually looked at one of these proprietary products and microfracture plus, and they said, what does this do? What does microfracture plus do? Or what does this scaffold do? So they looked at bovine femoral trochlea cartilage explants and they treated these explants with a proprietary microfracture plus-type product and bone marrow concentrate. And then they sealed that defect with a commercially available glue or with a biologic glue that was generated with the patient's own PRP, PPP, or autothrombin. And they found, or they looked at the repair constructs for cell viability and the ability of the cells to adhere to the scaffold. And then they assessed their biologic products for IL-1RA and concentration, and then looked at proteins. What's actually in this stuff? We all talk about it. We all think we know what we're talking about. What's actually in it? And so what they found, this proprietary product supported chondrocyte and MSC attachment within 24 hours, maintained at 48 hours. Bone marrow concentrate had the highest concentration of all the biologic products, including PRP and PPP and thrombin of IL-1RA, which is important from an inflammatory perspective. And when you look at the protein analysis within that matrix, there were over 250 proteins, many with known anabolic roles in cartilage matrix protein synthesis. And so there is something to this. There is something with regard to using a scaffold in the setting of a microfracture defect to help improve the biology of repair. And so they supported, or they concluded, that this particular product, but I think we can extrapolate this to really any product on the market that offers an extracellular matrix, has the chemical composition and architecture to support cell adherence, migration, and provide bioactive proteins to improve our cartilage repair. And then outcomes. So these are hot off the press. First paper's in 2020. Second paper's recently published in 2021. And when you look at these papers, these are, again, two-year outcome studies looking at microfracture plus with a proprietary product. Both the clinical and the imaging outcomes are supportive. The big question is how does this compare to standard microfracture, and how does this compare to some of the more known, historically durable techniques that we're about to hear about? But there is now some data to support the use of augmenting your marrow stimulation with a biologic and with a scaffold. I wanted to provide one case example. This is in the shoulder, but the same thing applies. And so this was a patient who had a posterior glenoid chondral defect, almost equivalent to an OCD lesion of the knee, with an associated posterior labral tear. This is an overhead thrower. And I bring this case up because these concepts, while we're in a knee ICL, these concepts do apply to the shoulder as well. And so in this case, you could argue, do you even need to treat this defect? How big is it? How symptomatic is it, et cetera? But the same principles apply. So we use curettes, and in this case, ringed curettes to create nice vertical walls. And then in this case, using a drilling technique to create the microfracture holes, typically spaced three to four millimeters apart from each other. And again, you could say, okay, I'm gonna call it quits. But in this case, I'd like to add everything I can to this small defect to hopefully help it heal. And so we end up adding a biologic. And in this case, we use, so to speak, microfracture plus, where we create on the back table a mixture using the patient's own concentrated CPRP from bone marrow aspirate that was concentrated using a centrifuge machine, and then mixing that with an extracellular matrix with the so-called scaffold, and then placing that with fiber and glue into the defect site. And let's see if I can get to the next slide. And so here's that preparation on the back table, again, with the patient's concentrated PRP from their bone marrow aspirate that had been processed in the centrifuge machine. And you kind of make a one-to-one mixture until you get a nice putty-like paste. And what's the right consistency? Well, I think that could be studied for decades, and it's gonna just have that feel factor for everyone. But I like to make it like a nice putty as though I can smear it potentially in that defect. And so we get that ready to go, and then we are able to get that into the joint in a dry scope. And this same principle would apply to the knee. I will tell you, when I was searching my cases to find a microfracture plus case in the knee, the challenge is I don't really have too many because, as you'll hear from my colleagues, there are many other chondral restoration procedures and reconstructive procedures that tend to be more durable for the types of lesions that we see. You still need a small lesion to do a microfracture surgery. And many of us, fortunately or unfortunately, don't tend to see those small lesions. But this is what it looks like at the end of the day. And again, the same thing applies to the knee. And you wanna get it nice in that lesion. And the key is the vertical walls here to contain this, and then cover it up with fiber and glue at the end. And you hope that with this secret sauce that the cartilage will be there. So the treatment algorithm, we're gonna hear a lot more about the other procedures today. For in-season athletes and those with mechanical symptoms, debridement is still my workhorse. Marrow stimulation in my practice doesn't come without a plus. So I don't do what I like to call a naked microfracture. These all get a plus, whether it's a biologic, a PRP, or bone marrow, or some other biologic. But everyone gets a biologic. I think if we are going to use microfracture, we should give it everything we can to make it work. And the literature now is favorable for that. And then we'll hear about these other techniques, including autograft, allograft, and cell-based transplants down the road. With that, thank you very much. Oh, I guess some take-home points. You must consider the joint as an organ. It's best for small, contained lesions when we talk about microfracture. The big question is durability. And can we make it better? I think we can. And these are things as surgeons that are in our control. Thank you. for Dr. Frank before we move on. So I have a couple for you. We'll keep you on the spotlight here. There's a nice dog there. So one is you talked about debridement and you mentioned the in-season athlete. You know, when you see a target like a loose body, an obvious chondral flap, I think that, you know, is an easier decision to perform a debridement because oftentimes we see that gets better. What about that chronic patient that you can't really see necessarily a loose body or a chondral flap? Do you think debridement still has some value in that setting? Yeah, I think the big question in that setting is understanding their symptoms. So for that chronic patient, are they swelling? Do they, can they do the one finger test? Can they point to their joint or their chondyle and say, that's where it hurts? Or are they doing this thing, it hurts all throughout the knee? But I do think there's a role for what I would call staging scope in those patients when they fail non-operative treatment, even if it's chronic, even if they don't have a delaminating flap or a loose body, they can still have mechanical irritation from the cartilage lesion. And I don't like to go right to a transplant unless it's really that perfication where I can predictably say this is the only surgical option that I would pick for you. I think oftentimes I need to get my probe in there. I need to feel the defect. The MRI can often under-predict the size of the defect. And we, I think we've all seen that. And so if you've ordered a graft and it's not quite the right thing or you haven't ordered a graft and you wish you had, so I like to do that arthroscopy and debridement. I think the challenge is how much is enough. It's kind of like meniscectomies. You want to leave as much as you can so that you don't hopefully have to come back and do the cartilage restoration procedure. And those with those chronic lesions I think are tough. But yes, that's a long-winded answer to say there is a role in those chronic patients. And then the second question, we all noticed that you had to show a shoulder case to find a microfracture, microfracture, bless her, naked microfracture. I think that's the new term that I heard from you today. So maybe just go down the panel by a show of hands. Would anyone in a patient outside of a study treat an isolated cartilage lesion with a marrow stimulation technique? So I'm getting some sighs. So a lot of, Andreas has a maybe, so he wants to say something, go ahead. No, I mean, I always, I try not to be too campy and I've sort of been billed as an ACI, I guess. I always try to avoid saying microfracture is awful, should never be done. I can, to answer with a nebulous answer, I can think of a situation where I would do a micro-drilling I totally support Rachel on that. If it's a young patient, acute injury, like a really small, a centimeter something, then yes, I could think of that. How often do I actually do that in my clinical practice? Two, three times a year. So I think it's rare, but yes, there is maybe a role. And I think it's a challenge because that particular lesion, like we've all included those patients in studies and honestly, they can do well and their MRIs can do well. The question is, how would they do it with an alternative? And that's really the key. And they probably would do well with just an agreement and that's what you had referred to. And Adam Yankia had done a study looking at just a simple chondroplasties in preparation as a staging scope to set up a larger procedure. And many of them actually did well, at least for one of the first two years where after that, you don't wanna see them again. Okay, we have a question here in the front. Yes, how aggressive are you on the rehab after doing the micropracture plus procedures, especially in the knee? Great question. I treat it like any other cartilage restoration procedure. So if it's on the condyle, if I'm doing any cartilage, including microfracture plus, I'm really making sure that the alignment is appropriate because I think a cell-based procedure with malalignment, even subtle malalignment is subjecting that cellular transplant to shear versus a more structural technique, such as an autograft or allograft osteochondral transplant. So I do it just like I would do my Macy. And almost, I can't think of any differences in rehab other than what I would do for a Macy. And my patella femoral cartilage is a little different than my tibia femoral cartilage. But the fact that it's just a microfracture, to me, that's the hardest part. And I see so many patients who've had their scope at an ACL and they had a microfracture and they were never rehabbed appropriately for their microfracture that just so-called happened, or so to speak, happened during their ACL. And lo and behold, their ACL is hopefully fine, but their knee hurts and they can focalize it to their, or localize it to that focal defect. So I think that's the challenge. If you haven't prepared your patient for a cartilage rehab, and I can speak personally to this as a cartilage patient, if you haven't prepared them, that procedure's gonna be bad. Your outcome's gonna be miserable. So it's important, even though it's just a microfracture. One point to that, and I think this discussion is actually more interesting than the talks, but I'm speaking from my own talk. How often, down the panel, how often have you done a microfracture with a concurrent procedure like an osteotomy? I have not. Because you rightly said so for every cartilage case, you really want to look at all the co-factors, it's exactly what Erin had said. But I think the reason why microfracture's being done so commonly is because it's an arthroscopic procedure that you can quote-unquote sell to your patient pretty easily. The other extreme is an HDO where patients say, what do you mean you want to break my leg? And I do that a lot, but it's a discussion. So I have not really seen any patients, I think, where it's a small cartilage defect, but they have malalignment, and you think, well, this is just an OATS plug or a microfracture, but then you also do an HDO, which is the right thing to do. It's just hard to go that step. It's much easier if you say, well, we have this big, expensive, complicated cartilage transplant, we should really protect that, versus, you know, let's do the microfracture, and if it works, that's great. Because many people have said, well, you cartilage guys always accuse microfracture of failing, but that's because most microfractures don't get this added meniscus transplant and third-time revision something. So I think that's an important point. And then number two, we recently also looked at PearlDiver because I always wondered why there's so many microfractures being done, and whether those are real microfractures or those are sort of insurance microfractures where you do a meniscectomy, and then there's a fissure, and you make a hole because that can be built separately. And the only way to find out, I figured, is rehab, so thanks for that question. And only 1% of microfractures had a CPM post-op. So could be that this is just because insurance doesn't pay for a CPM anymore, or there was one paper that showed you don't need a CPM and patients don't like a CPM, but 1% of all microfractures with a CPM makes me wonder what the indications were. But now too. See, this is why I like these meetings, because I've learned two new vocabulary terms. There's now naked microfraction, insurance microfracture that I can incorporate in my vocabulary. Thank you for that.

microfracture

marrow stimulation techniques

cartilage pathology

knee joint

patient expectations

organ