All right, last but not least for the session, we invite up Jack Farr. He'll talk about the treatment of subchondral bone, looking at BMA, BMC, and subchondroplasty. Thank you, Seth. I think we've kind of reached a consensus, is that it's really important to know what you're treating. So arriving at a diagnosis and all OA is not the same, we've heard about wet and dry OA, and so this is sort of my approach to subchondral bone, either using biology or using calcium phosphate. These are my disclosures. So exactly, what are we treating? So at least for me, most of my patients are already coming in with MRIs, and we're looking for symptomatic bone lesions. So we're going to correlate where their pain is, and that they have this T2 image, and we call it the radiologist. When they first saw this about in 1985, 86, it was the same signal as they saw with fluid. So they said, hmm, must be fluid, we'll call it bone marrow anemia, and that has stuck. So that's in the radiology literature. At least we've gotten some of them to say maybe bone marrow-like lesions, because I think I like the term either bone marrow lesion, because that's real nebulous, or even I like to think about it as a stress response or actually a stress fracture. And if you look, this is actually in the radiology literature. It shows there's really very little true edema, and instead there's some microscopic fractures and actual failure to heal. So there's a little necrosis, there's a little fibrous tissue. So I think thinking along the order of a stress fracture helps us both in planning treatment and understanding the pathology, and you can see it on micro-CT and histology. There actually are little fractures. So bone marrow lesions, are we just now talking about them since subchondroplasty came to the surface? No. It's been around mostly in the rheumatology and radiology literature for over 30 years, and then you heard yesterday in 2008, Felson correlated these bone marrow lesions to symptomatic OA. So that's really when it's taken off. And so, okay, we have a lesion, we know it's symptomatic, what can we do to help that patient? So correlating with symptoms, we all have seen patients come in and you get the x-rays, you throw them up and you say, oh, you're going to need a total on your right knee. No, I'm here for my left knee. So they're bone on bone and they don't hurt. So the presence or absence of joint space narrowing is not significantly associated with knee pain. We've all seen that in our practice. If you do look at the symptoms, there's a strong correlation, as Felson showed, with these bone marrow lesions. There's moderate to synovitis and effusion. So we heard yesterday, some of these patients have effusions and synovitis, that's probably an intra-articular type of injection treatment. But if you have a bone marrow lesion and it's a bone problem, then maybe you need to consider a bone injection. And that's what we're talking about. If you look at these bone marrow lesions, there's a real high correlation with progression of disease. So I'm thinking of these as bone stress fractures. And for using BMAC or BMAC bone graft or DBM added, I'm thinking that I'm augmenting the fracture healing process. You've already heard about use of unloader brace or crutches. So this is fracture healing in my mind. In the calcium phosphate injections, there's a variety of them, but I think those more of an internal splint. So these are some examples. There's an isolated one. We can even see these after treatment with surface therapies for cartilage restoration. These are the different types of injection techniques. You can see the calcium phosphate on your left, and the BMAC doesn't obviously show up fluoroscopically. So now we'll go into, this is just a brief literature. Hernigau is probably the leader in the bone marrow aspirate concentrate, and Sharkey and Cohen are for subchondroplasty techniques. Let's see if this is going to run. There we go. So you can have DBM gel added to it, DBM granules. There's a mixer. You've already seen how you aspirate. Separate it so you're getting the high leukocyte count. We like to have the plane collinear, so we flex and extend until the plateau is collinear for a plateau. I like to use a wire driver and then overdrill, because some of these, there is a lot of sclerotic bone, and I'd like to have a large channel to allow ingress. So then I'll take that out. Now I have my cannula over that, so I actually do have a lot of area for whatever I'm injecting. In this case, we're seeding it fully. We're going to then mix it. This is a case, you know, you're thinking you're treating this empirically. It's a stress fracture. We're going to use DBM to augment healing. I like the gel better than the granules, because with this mixer, you can actually get it to completely mix, and you have better flow in your needles or cannulas. I'm typically using a 3-5. So in this case, we had 3-4 cc's times 2. I like smaller syringes, so I can, my weak thumbs, I can actually push it in and get a better flow. We'll inject, pull back, and inject. Many times I'll activate this with thrombin to get it to clot. This is just another technique. As you can see, we're about 5 centimeters posterior to the anterior iliac spine. We're going to aspirate, and I really, you know, Hrnagov showed us you really need to get some strong vacuum. So I'm actually doing it at this one level, then I'm going to go down to another level and repeat and repeat. This is a symptomatic patient. She had a similar bone marrow lesion on her contralateral knee that responded in a similar treatment. So once again, we're drilling, the patella is very dense bone, so it'd be very difficult to do this by hand. Now we're injecting, pulling back, and then injecting again. In the patella, you're lucky to get 4 cc's. I would encourage you not to use calcium phosphate in the patella, you can get necrosis. This is another patient, so this is the opposite, and I'm just using a little different technique. This is a cannula that has a closed tip and side flutes, and so you're able to get different areas of aspirate. So why am I turning it here? It just makes the stylus easier to get out. And then this has a nice little helical turn where you can actually turn it 180 degrees and you're moving it one centimeter and getting it from a completely different area. So once again, you can see I'm really applying suction, I only want 1 or 2 cc's, and I'm going up 1 centimeter and getting another 1 or 2 cc's for a total of, however, you can go down maybe 7 centimeters so you can get up to 10, 14 cc's. We're adding to the bone marrow aspirate, once again, a DBM gel, mixing it thoroughly. And then in this case, there we go, once again using a smaller syringe, 3 cc's. In this example, I've already drilled. When you're doing this fluoro, we're not using a true lateral LENI, we're using a true lateral of the patella. So now I've found the hole that I already drilled and then I'm putting this cannula across. It's just an alternative to do it by hand. I have it in position and once again, then injecting, you see it's important to have adequate room for it, especially if you're mixing it with DBM because it is fairly thick. This next one, this is courtesy of Steve Cohen, he and Sharkey, really they originated subchondroplasty, that's a specific term for their corporation, but there are many different companies out there that sell predominantly calcium phosphate, although some of them will have sulfate. They have additional additions. This particular one has methylcellulose, which improves the flow. You really need to pay attention to how you dilute these. It's very sensitive to the mixture. If you have too much water, it's going to be more of a slurry. If you don't have enough, you're not going to have flow. Once again, trying to be collinear, trying to go through good bone into the area of the lesion. Sharkey has proposed that what you're looking for in this, so everybody is using MRI. I like to have my MRI at least two plain images up in the OR, so I'm triangulating in my mind. We'd like to have this be a support that is just in the area of the femur, it would be just proximal in the area of the tibia, it would be just distal. This is a common treatment he's using on both femur and tibia. This would be for medial OA. You can see advancing. I like to be more collinear, so I know exactly how far away I'm from the joint. I like to go back and AP and lateral. I don't want to have surprises after you do these. If you get an MRI, it does not just flow everywhere and just kind of go and make you look good like maybe when you're doing it with cell therapy. This stuff goes exactly where you put it, and if you put it in the wrong spot, it's going to show up glaringly on the MRI. This is the mixing. Typically you're mixing it with saline. It is an option. You could mix it with PRP or even cells. There's some debate whether or not when this forms the crystalline, what do those crystals do to the cells? I think certainly the science is not there, but that would be of a concern for me. Using typically one cc's and for femur and tibia, you're going to typically use four to five. Once again, I would not use it at the patella. I had a couple of necrotic patella as a result. With this, unlike the biologics, you're actually going to see this blush. You can see at the tibia, there's a little density there, and you would like to see it go up and actually go to the level of the subchondral bone plate. Then to make sure you have used all the available calcium phosphate, you actually will insert the candle at the end. It only takes a few minutes to cure, so if you remove the candle too quickly, you will have some extrusion immediately adjacent to the bone. Sometimes that can be an irritant to the patient. Most of the time, if you'll just leave it in for a couple of minutes, it's adequately cured. There you can see the effect of the subchondral injection, and then you simply remove those. Anybody have any questions for Jack? Yes. Go ahead. What procedure code do you use for the ASC to get reimbursed for this? So the aspirate is 38220. You're treating this closed treatment of a patella, tibial, or femoral stress fracture and so those are 27510 for the femur, 27520 for the patella, and 27530 for the tibia. Yes. Do you allow them to fully wafer with a bone marrow injection versus the subchondroplasty? It depends upon where it is. In other words, those were patellas, that was a very small lesion. And the size of the lesion, I have not, certainly if you have a huge area, I mean that person is going to be markedly symptomatic, but I've seen relatively small areas of bone marrow lesion in a patient symptomatic. So that patella was treated, and just like for most of my patellar treatments, as long as they're on level ground, they're only putting .5 body weight to the patella, so I let them, they don't need a brace. For medial compartment, lateral compartment, if it's truly OA, then I want them in an unloader brace, so I'll keep them on crutches until they can calm down and be fit with their unloader brace, which is usually a week to 10 days. Gloria? Thanks for that. You know, this is a subject that I'm really interested in and have spent a lot of time with and I'd like to offer a potential alternative to the subchondral fracture, because we had looked at a lot of these with New England Baptist, where we got the retained tissue from total knee, and we looked at it histologically, and we looked for, I think it was David Burr who first had the hypothesis that these were like sub-micro fractures that were proliferating, and what we found was that they're really, we had a hard time finding any evidence of any of these fractures in the tissues, but subsequent to that, we were working with David Hunter, who was at New England Baptist at the time, and he had done an interesting study, a contrast study, looking at the influx and outflow from, on MRI, sort of real-time MRI, of contrast, and had gotten the coefficients of flow in and flow out, and what he found was that there was a lot more flow in than out, so the drainage was blocked, and I just wonder if what you're doing is basically, so it's like this blood under your fingernail, it hurts, and then what you're doing is filling that hole, and you're actually putting sort of compression on that, so it can't fill and it can't hurt anymore, as opposed to it actually being a fracture. So at the end of the day, they get better, so it probably doesn't matter, but I'm not so sure that it's just subchondral fracture. Well when this first came out, the criticism was, well you really don't need to inject anything, you're just doing, you know, Hungerford and Ficott, like years ago, were doing, you know, the ultra-high lateral compression syndrome with the patella, and they would just drill the patella and the patient would get instantly better. So in my mind, it doesn't really matter to me, as long as the patient's getting better. I have drilled in the past, and it seems that, at least what's in the limited literature, and my experience, that I'm having a better success rate than isolated drilling alone. Yeah, that makes sense, because if you're just drilling, the hole will still be there, so it's going to fill back up once that drill hole sort of closes over. Do they recur for you? Have you had people come back in pain, or have... Well, there's a couple things. If you're treating true OA, so they have KL3s, I don't do KL4s, because I think, you know, the probability of making them better is very low, but the KL3s, I would expect them to come back, because you haven't treated the underlying disease process, but I've had patients that are several years out. I mean, the goal is to sort of kick the can down the road, and you're trying to delay there totally as long as possible. I've had several patients that are, you know, a few years down the road, and that's what Felsen, I mean, not Felsen, Sharkey and Cohen, they were delaying total knees in a large percentage of patients over three years, so that's of some benefit. Any final questions for Jack? So I think we're a bit over time, so I appreciate all the questions, and it was a great session.

subchondral bone treatment

BMA

BMC

subchondroplasty

bone marrow lesions