用于膝关节手术的超声引导内收肌窦和 iPACK 阻滞术

- So my name is Chris Pennell. I'd like to welcome you to the Sono site webinar on ultrasound guided Dr. Canal and IPAC blocks for knee surgery. And before we begin, please be advised all attendees are muted and you can type your questions into the q and a box in the tool bar located at the bottom or the side of your screen. And we'll conduct a q and a session at the end of the presentation to get to all those q and A questions. And this webinar will be recorded and archived for future reference. So to begin our presenta, excuse me, our present, our presenter is Dr. Richard Teams. Dr Teams is a dedicated anesthesiologist with unique background in nursing who excels in working with trauma and critical care patients. He trained at the busiest trauma center in the US and has exceptional regional skills and ultrasound technique and multiple nerve block modalities. He's currently the, the director of regional anesthesia at St. Peter, sorry, at John Peter Smith Hospital, as well as the National Clinical Director of Regional Anesthesia for Envision Physician Services. DR Teams is an officer in the United States Army Reserve Medical Corps. And his clinical interests include acute pain management, regional anesthesia, advanced airway techniques, and cardiovascular anesthesia. He has a genuine interest in enthusiasm for teaching clinical and acute pain and regional anesthesia and is a bilingual English Spanish patient advocate. Thank you so much for being here, DR. Teams. And with that I'll go ahead and turn it over to you. - Hello and good evening. My name is Dr. Richard Teams. We're coming to you talking to you about another, with another episode of behind the scan talking about anesthesia for knee surgeries. So today we're gonna talk quite a bit about how to get good analgesia for patients going for total knee surgeries, which also there can be some applicability with other types of procedures and that sort of thing, which we can talk a little bit about today. But let's dive into it. We're, first of all, what we're gonna do is we're gonna talk about what are our options for knee surgeries. Well, historically, as we know, we've really not, you know, in the distant past we've not done hardly any blocks. And so, you know, PO and IV pain medications have been a good mainstay. Also doing spinal anesthesia with some dur morph has also been a good mainstay. But more recently we started doing the DR Canal blocks. Now even before got Dr. Canal blocks, or even still a lot of patients I know or a lot of clinicians are using femoral nerve blocks for total knees, which we'll talk a little bit about. But the new kind of in vogue has been doing adductor canal blocks. And there's a lot of good reasons for this one, not the least of which is the motor neuron sparing component of an inductor canal block, which we're gonna talk also about. But there's also some other blocks in here that we're gonna talk about. N-V-N-N-V-M stands for nerve to VASST medias. We're gonna talk a little bit about that. And then the A FCN is the anterior femoral cutaneous block. Other things that are not actually listed on this are the IPAC and selective tibial blocks. And this is for posterior knee pain, which we're also gonna get into. And I'm also gonna show you how to scan. So first what we're gonna talk about is going to be our adductor canal blocks. So our adductor canal blocks, like I said, is kind of the mainstay for total knee surgeries. And what we get when we, the analgesia that we get for saphenous nerve, for adductor canal box is blocking the saphenous nerve primarily, but the saphenous nerve gives off a lot of innervation to the anterior knee. A lot of the anterior genuss come off of the saphenous nerve. And this is the canal. So the canal kinda looks like a kind a triangle. It's a neurovascular bundle underneath the sartorious muscle. So you're gonna have the saphenous nerve, but then in addition, you're also gonna have the, what's called the superficial femoral artery and also the femoral vein, which is just a, a little bit more medial. Now, one of the biggest studies that was done was this one about the biggest benefit to doing adductor canal blocks versus doing femoral nerve blocks. And the big one take home message was that adductor canal blocks prevented quad weakness versus femoral nerve blocks with with, with no real significant difference in postoperative pain. And that's kind of the big take home message was, well how much analgesia could you get with an adductor canal block versus a femoral block? And in this study they did show that there wasn't a big difference in postoperative pain, although the adductor canal block group did have a little bit more pain than the femoral, but in the study it showed that it wasn't technically clinically significant. Now we're gonna talk a little bit about why that can be here in a minute. Why does a femoral nerve block get better analgesia than an adductor canal block? There's actually some really good reasons for that. So let's kind of go into this a little bit. So I like to divide the leg into three zones. There's a zone B and C zone. All right, B zone is pretty much described as right in between. I'm gonna, I'm gonna put up a little laser pointer here so you can kind of see what I'm doing here. So here's B zone here. It's pretty much halfway between the patella and the inguinal ligament or the A SIS. So halfway in between there is kind of B zone. A zone is obviously above more proximal C zone is a little bit more caught at. But how these other two zones that A and the C zone are described under ultrasound is based on where the artery is in relation to the sartorius. So what I mean by that is, is as you move up and down the leg, the artery will kind of rotate itself underneath the sartorious muscle. So the higher up the leg you go, the, the closer the artery is gonna get to what's called the adductor longest muscle. Okay? It's gonna kind of move a little bit more medial here. And as you go down the leg, the the artery is gonna move closer to the vast medias so muscle. So one of the other things that contributes to pain for the knee is this nerve to VASIs medias or this NVM nerve. The nerve to VASIs was originally thought to cause mo mainly motor to the ssus medias muscle, which makes a lot of sense. But they did some cadaver studies on this and they showed that there is indeed some sensory component that comes to the anterior medial part of the knee from this nerve to VASIs medias. And they found this, they kind of discovered this inadvertently by when they went in to block the adductor canal, a lot of times P, you're not able to get right in the adductor canal initially. I'm sure that's happened to some of you where you go in to try to get into the abductor canal, you put some of your local anesthetic there and you're like, oh, I'm outside of the adductor canal. I see my local anesthetic kind of spreading underneath the sartorious muscle and it's kind of coming up towards me a little bit up the sartorious muscle. I need to advance my needle a little bit. That certainly has happened to me. Well they found that the patients who that happened to inadvertently had better analgesia than the ones where they got in the adductor canal the first time to begin with. So after doing some cadaver studies, they found that there's this nerve ssus medias, which lives in between the sartorious muscle and the VASS medias muscle. And like I was mentioning, it gives off some sensory component to the anterior medial aspect of the knee. So, so I've begun blocking this nerve every time I do an adductor canal and it's actually really quite simple to do. I'm gonna show you how to do that here in just a minute. When we, when we scan, I'll show you an ultrasound, but here's a really great image kinda showing this is a MRI of this. This is after they put some gadolinium in the adductor canal and you can see the local anesthetic is tracking all the way up here. And this is actually the, this is actually the saphenous nerve. Now the nerve di vass actually lives right here in between the sartorious muscle and the vastest medias muscle. This is, this is the vast media muscle and this is the sartorious. And so in this area you could tell this is probably more a zone meaning higher up in the leg because this is the adductor longest muscle and you see the artery is closer to there. So if you look at this picture here, this is also a zone, I'm gonna go back a slide. There we go. So a zone again is up here higher in the leg. And as I was mentioning, a zone, the superficial femoral artery is gonna be closer to the adductor longest muscle right here. Okay? And this is the saphenous nerve, which is right there. Now where does the nerve di VAs medias live? It lives right here in this fascial plane in between the Sartorius and the Vastest medias muscle and it's easily blocked when you do an adductor canal block. So if I come in here with my needle and I pop into the adductor canal, you can clearly see there's a nice triangle here, pop into the adductor canal, give my local anesthetic here, I can easily pull my needle back and maybe dive down and just inject a little bit of local anesthetic here. And when I say a little bit, I inject five ccs of local anesthetic when I do my nerve avast block. Okay? And that's all you really need. A lot of times sometimes you can actually appreciate or see the nerve di medias, but most of the time I don't really see it. I don't appreciate that nerve in between that plane. But just 'cause I don't see it doesn't mean it's not there. I can just put a little bit of local in between that fascia and I know pretty reliably I'm gonna get that. So again, like I was saying, this is a zone. Now if I go over to this other image, it's the same one, but this is the image of them doing the block. You can see that this is higher up in the leg. So why, why do I advocate for these different zones? Well, the higher up the leg you go, the better the analgesia for the knee is. But also the higher potential for some quad weakness also becomes the lower down the leg you go, meaning towards C zone, the lower the analgesia for the knee can become, but also the less likely to cause quad weakness. So what, so it's kind of a, it's kind of a, you know, you can be caught between a rock and a hard place there. What, what's the best approach? Well, I would say for a knee going to a zone is gonna be best 'cause I wanna get good analgesia. However, the key there is gonna be the volume of local anesthetic that you use. If I were to blast the adductor canal with 20 or 30 ccs of local anesthetic, I'm going to get quad weakness regardless of if I'm in C zone or B zone or a zone because the adductor canal is just that, it's a canal. And so local anesthetic is gonna spread up that canal and it's gonna spread down the canal. Well, if it spreads up the canal to a sufficient amount and then get to the inguinal ligament, if it gets to the inguinal ligament, I'm gonna be the, the femoral nerve. So there's been some really good literature out there to support what is the proper amount of local anesthetic to put in the adductor canal to perhaps not cause the quad weakness that we're trying to, to to avoid but also have good analgesia. And I say the magic number and based on the studies is 15 ccs. So when I do this adductor canal block, I'm gonna put 15 ccs in my adductor canal. I'm gonna put five ccs in between the sartorious and the vass medias in order to get the nerve to vass. Okay, now if I go to this next image, this is B zone and I can tell it's B zone because the superficial femoral artery is right smack dab in the middle of the sartorius. Okay, if I were to move up the leg, then my artery is gonna slide closer or slide underneath the sartorius, but closer to the adductor longus muscle. If I were to slide down the leg, this artery is gonna slide this way closer to the vast medias muscle. So let's look at this anatomy here. So here this is the saphenous nerve in the adductor canal. Clearly we can see a nice triangle here. I'm gonna come in here and pop in here and and infiltrate there to get an adductor canal block. And then the nerve DITs is gonna be right here in between the sartorious muscle and the VAs medias muscle. Okay, so if I'm doing a adductor canal block for maybe an ankle surgery, I don't really care what zone I'm in. Also I don't care about the nerve nass because the only nerve I really care about for an ankle surgery is gonna be the saphenous nerve. But if I'm doing an a knee surgery, I need to do a a saphenous nerve block. But in addition, I'm also gonna do this nerve divac medias. Okay, so here's a nice image coming from from my hospital actually showing just that where I have the superficial femoral artery, here's my sartorius, this might be BAB zish, you can barely see the Dr Longus kind of p poking out here. This is a nerve ssus and I've actually gone right through this fascia plane in between the sartorius and the VAs medias. So, and this is my saphenous nerve right here. Now one cool little trick you can use to know that you're inside the adductor canal is start injecting and then all of a sudden stop injecting. If you stop injecting and all of a sudden you see that local anesthetic kinda kind of contract or go down, then chances are good you're actually inside the adductor canal. Because what's happening is as you stop, as you stop injecting, that local anesthetic is spreading CEF lain coda up and down that canal. Okay? But if, if you stop injecting and it still kinda looks the same, then you may be outside, you may be in in the muscle, you may be in the fascia and you may need to go a little bit further in. Okay? So there are other nerves in the leg that that contribute to pain for, for the knee, how many of us have done an inductor canal block and it's looked just like that and we're like, we are awesome. Look, we are the regional anesthesia gods, we or goddesses, however you wanna say it and it looks amazing. But then you go to PACU and the patient's screaming in pain, you're like, well you know that patient's clearly psychotic, you know, this is not me. You know, I did a really great block that I think has happened to pretty much anybody who's done an a Dr Canal block. That certainly has happened to me. But, but it may not just be that the patient's crazy, it may be that there's something else we're missing. And one of the things we could be missing is this anterior femoral cutaneous nerve and also the posterior genus which come off of the sciatic nerve, specifically the tibial nerve. So let's talk about those for a little bit, particularly we're gonna talk about this anterior fem cutaneous nerve. So here we have a picture of the leg and right up here in the inguinal ligament, right off the inguinal ligament, you have these little spidery nerves that come right down here and they're cutaneous nerves, okay? And they come all the way down here and you can actually see this, this, this distribution here is the anterior fem cutaneous nerve distribution. Look where it is, it's right over the knee and it comes right down here. Well, where's our incision for a total knee? It's right here. Okay? This is our incision for a total knee. And so I kind of figured this out that, you know, I was getting a good job getting the, the deep aspect of it, of the knee, but I was missing the, the incisional pain, the pain that's coming from here, from these anter fem fem cutaneous nerves. And so I started reliably blocking 'em and I, I did it initially with 2% lidocaine just to see if I could block 'em very quickly. And I do it in pacu, see if I could book, take that pain away immediately by doing just a little bit of a field block just up here proximal to the, where the incision is. And it did, it took the pain away. Now I do it reliably and I do it under ultrasound. So how do you do it under ultrasound? Well, just like the nerve di, I can do this block reliably under ultrasound. And a lot of the times you can actually see these anterior fem cutaneous nerves. In fact, in this I can see maybe four of 'em. So let's, let's point these out to you. So first of all, this here is my sartorious muscle and this looks like B zone. Okay? So here is my superficial femoral artery, okay? And this is probably, this is a flipped image from other one. So this is my AVAs medias, this is my adductor longus, this is my saphenous nerve here. Well the adductor or the anterior fem cutaneous nerves, they live on top of the sartorius in this fassal layer that is right on top of that. See all this little kind of schmutzy, you know, area here we call this kind of S speculation tissue here. This is all connective tissue, all right? This is all obviously adipose tissue, which is right here. But then you have this little layer of this connective tissue and you have these anterior F cutaneous nerves. So this is one right here, I'm gonna go back. So you can sometimes see these nice little hyper coic structures here. So this is an anterior fem cutaneous nerve. This is also one and this is also one. And there might be one right over here. So I'm gonna back up so you can kind of see 'em. So one is right here, another one is right there and another one is there. And there might be one over here on the edge and there can be three, there could be four. And sometimes there can be five of 'em that are, that are in there. So I'll usually leave my last five to six to seven ccs of local anesthetic. And I'll just come after I finish doing, doing my adductor canal, I'll just bring my needle on the superficial side and I'll just put one or two ccs right here on top of the sartorius. In these areas where I think these adductor canal blocks are, I ideally, the other way you could do is just do a, just a little fascial plane block. The only problem with that is, is a lot of times people will do the fascial plane block in this layer here in the adipose tissue. Well, adipose tissue isn't very interated, right? It's in this deep con connective tissue is where all the nerves live. So if you do it blindly, a lot of times, and this is the problem with the surgeons doing it, is they just kind of inject as they're going in the inject as are going out, only a little bit of is, is actually going in the right spot where we want it to go. But you know, I got an ultrasound machine, I know where these nerves are, and half the time I can see 'em. So why not just go in here and just infiltrate one or two ccs here by, by these nerves. So here's another image. This is again flipped. Sorry about that. But this is flipped. This is my artery down here. This is the adductor canal. Now this is my sartorious here and you can see this very thin fascia on top of the sartorius. And can you guys pick out where those nerve, the acti, anterior fem cutaneous nerves are? Well, there's one right here. I'm gonna go back. Can you see it now? So the one is right there. There's another one right here. I'll pull that back. There's one right there and there's another one probably right there. Okay, so when I'm done with my block, I would just pull my needle back and then just do one I and just maybe just do one cc or two ccs here, another cc here, another CC here. You can also track your probe a little bit more medial and maybe catch another one that's off the screen here. And just infiltrate in that little connective tissue area on top of the sartorius. Again, it's not below the fascia covering the sartorius, those cutaneous nerves live in the connective tissue on top of the sartorious muscle. Okay, so what we're gonna do now is we are gonna stop here and we're going to scan the adductor canal and then I'll show you how to scan it. I'll show you the different zones and then we'll try to see if we can pick out some of these anterior F fem cutaneous nerves. I'm gonna show you how to scan that a little bit. So one of the things I like to do is I'll just take the leg and just kind of frog leg it just a tiny bit just like that. And then I usually always start my scan in the A zone or in the B zone. So I, I pretty much just go right smack dab in the middle of the leg and sometimes I'm off. But let's, let's try this here. So here is in the middle of the leg. Oh, and then actually a little bit low, so this is, all right, so here is, here's my superficial femoral artery. And look at this, you can see really nicely my saphenous, my saphenous nerve right there. As I go up the leg that artery, see how it kind of pushes closer to the adductor longus muscle on her, her femoral artery kind of stays on this medial side of the, of the sartorious muscle here. But I'm just gonna scan down and you can kind of see it as you get down to C zone. See how it's kind of rotating. Oh, this is great. See how I was kind of rotating underneath the sartorious muscle? This is more B zone here. If I keep going further down, what will happen is, is the artery is gonna start separating itself away. See how it's separating itself away from the sartorious muscle? This is way too low because what's happening is the artery is diving down into the adductor hiatus. The other thing that interesting happens when you get this low is the saphenous nerve rotates almost to the 12 o'clock position versus up here it's almost, in this case it's at like the nine o'clock position. And this is actually really great here too, because you can see where this nerve avast lives, which lives right here. Okay? So this is where I would go if I was gonna do a, a Dr canal for a total knee. So I'd come down in here and put my needle right there for the saphenous nerve and then I'd back up and then I'd put five ccs right here in this little area, this area of hyper ity. Okay, I'd put, I'd put some right there. Okay, now let's see if we can appreciate any of the nerve to anterior cutaneous nerves. So this is the fascia layer I'm putting here on the, with my pointer here that I'm, that I'm looking at. And I'm gonna kind of scan up and down just a little bit. And yeah, maybe there's one right here. Okay, there might be one hiding in here, but this might also be one, right? Yep. This is one right here. And if I'm gonna go, I'm gonna go a little bit more medial. Sometimes I can see another one over here. Oh yeah, so there's one probably right in here. But if you put one or two ccs in these areas right here, you're gonna get those anterior simultaneous nerves and those cutaneous nerves, like I was saying, go all the way down the knee and they innervate right over the patella and it's gonna get the area of where your, where your incision is for a total knee surgery. Okay? Like likewise, I can go a little bit more laterally and see one or two. So this actually might be one right here. The more cephalad you go, the more clumped together they get. And they're, they're usually, they usually are more in a bundle. They're maybe three three of 'em versus the you branch. Once you go more coda, they'll start branching and, and, and there might be, you know, four or five of 'em, but usually the ones that are on top of the sartorious are the ones you need to get to get just this medial incisional pain from a total knee surgery. So this is where I go to get my anterior f cutaneous nerves, but also in the same view, I can get my saphenous nerve and I can get my nerve DSTs medias. So the great thing is, is I, it's kind, I can get three nerves, if you will, with just one needle stick. I go down one, one in the same needle stick hole, which I'm gonna use this little chopstick to show you kind of what my needle trajectory is. I kind of go in here to get my saphenous nerve and then I'll back my needle up almost to the skin and I'll kind of drop my angle of my needle a little bit so I can get the more superficial anterior cutaneous nerves. So three nerves in this one, in this one, one stick. I can get the saphenous nerve, I can get the nerve to AVAs medias, and I can also get the anterior femoral cutaneous nerves as well when, when i, when I do this block. And so I, I've done this now pretty consistently for over a year now with all of our total knees. And the analgesia they get is vastly superior to just doing in an adductor canal block. So let's go back a little bit to what I was mentioning before, which was about femoral nerve blocks. The reason why femoral nerve blocks are so great for analgesia of the knee is because a femoral nerve block, all of those three nerves are together in one, okay? The anterior from cutaneous nerves are branch off immediately as it exits the, the inguinal ligament, the nerve di medias is part of the femoral nerve. So it's all up there together. But the problem with it is you're getting all of those motor neurons that are diving down deep into the quad muscles when you get a femoral nerve block. So causing quad ness is not gr is not great. So the beauty of kind of doing this approach where you're getting the nerve di media, getting the saphenous nerve and getting the anterior f femoral cutaneous nerves is, you get the same analgesia you would get as though you're doing a femoral nerve block, but you don't get any of the quad weakness. 'cause those anterior femoral cutaneous nerves, it's only cutaneous, it's only sensory component. It's not motor. So, so the patients can ambulate, they just have, they just have a really good analgesia for the knee. Now the, the complexity of the, of the knee as far as analgesia goes, is a little bit even more than that. So let's, let's dive back here into the, into our lectures here and the PowerPoint, I'm gonna show you this as well. So when they do total knee surgeries, a lot of times they're whopping off the head of the, of the femur and the, and the tibia and you're, you're getting some other nerves there that, that you're not getting even when you do all those other three blocks. Well, what, what are you missing? What are we missing? Well, most of what we're missing are what's called the posterior gict nerves. And the posterior gict nerves come off of mostly the tibial nerve as it's kind of, as it's kind of splitting. So this is the posterior aspect of the, of the nerve nerve here. And you see the tibial nerve here and it kind of comes down here and innervates part of the posterior aspect of the, of the knee. And what happens is, is a lot of times it will, here's the common pro nerve. This is a cadaver, so this is the posterior aspect. Here's come pro nerve going laterally. Here's a tibial nerve kind of coming straight down the middle, and then it starts branching here and it comes down and it usually retrogrades back up and innervates the posterior condyles of the, of the femur here. Okay? So this goes back to the question of, well, how, how can we get the posterior pain from a total knee? Well, there's two ways of doing it. One way is doing an IPAC block, which I'm gonna show you here in a minute. The other one is a selective tibial block because if I just block this one nerve, I can get all these posterior gents that dive down into the condyles of the posterior knee. But if I do an IPAC block, I'm getting basically these articular branches of that, okay? So it's a little bit deeper. So if we look at an IPAC block, this is an IPAC block right here. So this is right at the level of the condyles, and you can actually see 'em right here, the femoral condyles. And then here's the local anesthetic that they just put just deep to that. So, so those nerves sit right on top of the condyles, they're living in this space. And so you're, what, what you do is, there's two different ways you can do it. One way is you can do it in the same position that you're doing an adductor canal and you just frog leg 'em. And so you come from the medial side. So my needle will come this way, right over the condyle and over this way, this is actually a lot further to traverse your needle actually has to traverse to further that tissue. The other way is you do it like you're doing a popliteal block where you kinda lift the leg up and you're coming from the, oh, excuse me, I meant medial side. So this was the medial side. So if I was frog legging the patient, my, my needle would be coming from this side. But again, this is a lot more tissue that I'd have to traverse to get to the lateral condyle. Conversely, I could do, like, I'm doing a popliteal block where I lift the leg up up and I'm coming lateral with my needle and I can just bring my needle right over here over the condyles. This is actually a little bit less distance for the needle to travel, especially if you have someone who has really big thighs. This could be a lot easier to do because, because of the, you know, it's less tissue to travel. And so I've kind of relied on teaching people doing it this way because most, for two reasons. One is I was saying less tissue to, to go through. It's, it's, it's a lot shorter. And number two is a lot of people are already very familiar with doing a popliteal block, right? We're really familiar with scanning for it. And so this is kind of an easy way of doing it. So here's a, this is going from the medial side. If you're like frog lagging and you put your needle right over the condyle, and where I start my infiltration is right here when I am right at the lateral condyle, in this case, I start my infiltration. I just, I just inject as I'm coming out. Okay? You can put 10 to 15 ccs of local anesthetic behind the, behind the femur, the femoral condyles. Some surgeons actually like to do this block on their own, and if they're doing some infiltration, they'll just infiltrate behind the knee. This is what they're getting, this is what they're hoping to get, rather, sometimes they're, some surgeons are better at getting it than others, but this, this is what they're trying to get. Now notice here, you're able to see the tibial nerve. So the, the, the husk, the outside husk of this tibial nerve is actually the same nerves that are innervating right here in this same, in this same image. So if we go back here to this image, you can see the complexity of the knee and the innervation of it. There is a lot of different nerves from different things going here. Here we talked about the nerve S, right? Well here's the nerve S intervening the anterior lateral part of the knee. So if we get that, then we're, we're good go. But we also have my saphenous nerve, which is giving a lot of these posterior gents. But then we got this inferior, this inferior patell, also the inferior gent, which is coming off the tibial nerve, which is again, one of those nerves that is part of that, the posterior ICT that you can get when you're doing an IPAC block. But you can also get, when you're doing a selective tibial block, now how you would do a selective tibial block. If this red line is where my probe is, this is my, this is my sciatic nerve notice, it's all together here. And as we start scanning down, notice they're starting to split. Here's my common peroneal nerve here. Here's my tibial nerve here. This is right at the bifurcation. If I even go further down, I can now see the, the tibial nerve separate from the common perial nerve. I can even go even a little bit further down here and notice, I can start seeing where these nerves are starting to branch out as they're diving down into the knee capsule. And that's where, that's where I block when I do a selective tibular nerve. The, here's the femoral condyle, you can see just deep to that, which is right here. But the, the beauty of doing a selective tibial nerve is a, I don't need to use as much local anesthetic. And that is very important when you're doing this block five ccs of local anesthetic is all you need when you're doing a selective tibial, like I was talking about for the adductor canal, if I use more than 20 ccs for abductor canal, I'm going to get a femoral nerve block. Likewise, if I do more than five or eight ccs of local for a tibial nerve block, I'm gonna get a complete sciatic nerve block, meaning that local anesthetic is gonna track up and it's gonna get this common peroneal nerve. And that is what we're trying to avoid when we do a selective tibial block. The reason why we don't wanna do a sciatic nerve block is 'cause we don't want to get the common peroneal nerve component. And the reason we don't wanna get the common peroneal nerve component is because the surgeons are very concerned about bagging the common prone nerve when they do their surgery. 'cause it's very superficial. It's easy to slice it off when they're sawn through the, the, the head of the tibia and the, and the, and the condyles of the, of the femur. And likewise, it's very impossible to do physical therapy on a patient who has foot drop, which you're gonna get if you bag the common perial nerve. So it's very important that you only use a small amount of local anesthetic when you're doing a tibial block and making sure that the common perial nerve is very far away from the tibial nerve, just like this image. So in this image I can see my common pro nerve, this is actually even closer than I would do it. I like going even a little further co add to where the tibial nerve is separating even further from the common prone nerve. And I have my needle coming and in this case it's coming from the lateral aspect and it's coming underneath. This is the femoral artery right here. And then I'll usually bring my needle all the way over here to the medial aspect of the tibial nerve. And usually I'll see a little bit of a crescent shape of my local anesthetic as I'm going around this, the tibial nerve. And again, five ccs. So I had a colleague who, who put 15 ccs on a selective tibial block. And, and guess what happened? He got a complete block of both the tibial and the common perennial. The patient had a really great analgesia, but you're, but he also got a foot drop because that local anesthetic tracked up the sheath got to where both the common perennial and the tibial nerve come together and wound up causing a complete sciatic block, including the common perennial nerve. So very important, only five ccs of local anesthetic. If you're doing a IPAC block, again, you can use a lot more local anesthetic, more dilute local anesthetic, usually 10 to 15 ccs. I'm not worried about getting the common peroneal nerve because I'm deep to it. I'm way deep, I'm all the way down here on the condyle so I can dump a lot more local anesthetic. So one of the limitations for IPAC block is it's deeper, right? And I need more local anesthetic, okay? One of the, one of the benefits of an IPAC block is I know I'm not gonna bag the coronial nerve because I'm deep to it and I'm getting the nerves right on top of the femoral condyle. Conversely, tibial nerve blocks selective tibial nerve block. The benefits of it is, it's a lot more superficial as you can actually see in this image. This is my tibial nerve. Look how superficial it is compared to, to where the IPAC block is very superficial. I don't need a lot of local anesthetic. In fact, I need to only use a small amount such as five ccs, only a local anesthetic. But the downside of a tibial block is I may get the common proin nerve if I give too much local anesthetic or if I am too proximal or up the leg and I'm too close to that common prone nerve, there's a chance I can get it. Less likely of a chance when you only use five ccs of local anesthetic, if you only use five ccs of local anesthetic and it's way after it's bifurcating and you're only getting the common nerve and I, and you go on the medial side of the nerve, I personally have not seen any foot drop from using only five ccs of local anesthetic. But again, that's always a, that's always a risk that can happen. Okay? So with that, what we're gonna do is let's scan this. I'm gonna scan doing a, a selective tibial as as a iPad block. Okay? So let's take a look here. Here is a little bit of gel here. So where you wanna start when you do this, it just goes straight at the papa tail fossa, okay? And most likely right in the center of your screen is gonna be your tibial nerve. And sure enough, there it is right there. There is my tibial nerve right there. And actually my common prone nerve is right here. So if I, if I scan up the leg, look at this. Here's common prone nerve, here's tibial nerve and they're coming together, right? Whoop, there you go. Coming a little bit lateral. So you're starting to come together right there. I scan down the leg. Notice here's common prune nerve. Here's tibial. We're starting to separate. Starting to separate right there. So you could, here's common perial right here. Here's tibial nerve. So you could go right here and do this block. Okay? Selective tibial block right there. Notice how superficial it is. Here's my ultrasound. You can see how deep it is. It's only one, maybe one and a half centimeters deep, not deep at all. And you see a nice pretty tibial nerve. Also deep to that you see the comma perennial or the, the pope artery, which is right there. Okay? Again, common parone nerve is here. One thing I just wanna caution you is, you know, I don't like doing this block when the patients are asleep because if my needle inadvertently traverses through the common proin nerve on the way to the tip nerve, well guess what? You may cause a common PR on your nerve neuropathy not even knowing it because you went through it, it may look like just normal tissue. If you're not really paying attention to this and you're really superficial, you may just blow right through it on your way to the tibial nerve. So I come, I try to come a little bit deep. I come about this level as I'm coming straight across. So I'll measure this. This is one and a half centimeters. So I'll put my needle about right here. Lemme get my little chopstick here, I can show you. So this is about one and a half centimeters up from where my probe is. So I should see my needle coming straight across, straight across the, the screen. And as I go, usually in between the vein and the, and the and the and the nerve, which is right here. And I like to put my local anesthetic right here on this medial aspect of the nerve, okay, for selective tibial block. Now for a, for a IPEC block, I can already kind of see what I'm doing here for an I pack look. I can already see my femoral condyle right here. This is my lateral condyle and I can already kind of see the trappings of my medial condyle. All I'm gonna do here is I'm gonna go a little bit deeper. Like I said, it's usually always deeper. So if I'm doing a lateral approach to this, I'm gonna, let me go back here. There, here we go. So lateral approach, I'm gonna bring my needle here again, it's deeper. So this is two and a half centimeters on her. So I'm gonna go a lot higher up with my needle up to about two and a half centimeters. And I'm gonna ride the top of the lateral condyle. I'm gonna bring my needle underneath here all the way to the medial side. And I'm gonna stop right here. I'm gonna stop when my needle is right. The midpoint of the medial condyle. Midpoint of the medial condyle is about right here. Once I get there, I'm gonna start my local infiltration with, like I said, 10 to 15 ccs local. And as I'm starting to inject, I'm gonna slowly pull my needle back out, pull it out until I get to here and I'm gonna finish up the rest of my infiltration. Don't use all of it obviously on the mito condyle, you wanna make sure you save some until you get to the lateral condyle and then I'll come out again. You can see the tibial nerve in the same image. Tibial nerve is right here. You get maybe do a little bit more gain this gain, that might be too bad. Let me, lemme see if I can clean it up a little bit. There we go. So here's my tibial nerve right there. Common proning nerve is way outta the way. So in this case you can see actually I can see in this one image I can see I'm gonna get my arrow outta the way there. I can see everything. I can see my tibial nerve right in the middle of the screen I can see my common proning nerve. In the top left, I can see my lateral condyle, which is right here. I can see my medial condyle. So in this one image, I could theoretically do either of the blocks we're talking about here. I could do a selective tibial block, which is right here, a lot more superficial, which is further far away from my common proin nerve, which is right here. One thing you do need to be aware of, I'm pushing, I'm pushing up and so I'm occluding this vein. So you don't wanna go right here and inadvertently get in the vein. That's why it's always important obviously to aspirate. But, but you could theoretically get it when you're doing the selective tibial because the selective tibial or the tibial nerve is pretty close to the popit tail vein. But also in this image I could, I could do IPAC block, which is just deep, which is right here, starting from the lateral side going all the way across to this medial side or the medial condyle. Okay? So both of these blocks are really great to get the posterior gena, the posterior pain from, from a, from a knee surgery. I get a lot of questions asking me, well, which one's better? Which one's better? And I think the best one to do is the one that you're most comfortable with. Some people really like using a small amount of volume and they like the superficiality of a tibial nerve. So they'll do a selective tibial with five ccs, a local, some people get really worried about that or the surgeons get really worried about that. And so they're really more comfortable doing a lot more dilute local and aesthetic getting the posterior aspect of the condyle. And so they're happy doing an IPAC block. Okay? So whichever one you you prefer, they're both really good at causing analgesia for the posterior aspect of the pain. Sometimes we've done these blocks in recovery room, the only limitation to doing that in the recovery room is what the dressing is like, right? So some surgeons only like putting a, a a, a awkward dressing on top of the incision. If that's the case, great, no big deal. You have the whole aspect of the, of the posterior genus or the of the, the back of the leg and the pope fossa available to you to scan. But if they, if your surgeon likes wrapping the knee all the way up, well guess what? It's gonna be really hard to do that. And postoperatively you either have to take the dressing down or not do it or whatever. And so it may be better to do at the beginning of the surgery. It just depends on what your surgeons like to do. And so it's kind of hard to do if you're like, hmm, you know, I don't, I don't wanna do it. And you know, or until after the surgery and your patient wakes up and they're hurting and they're hurt in the back of their knee, then you may have to take that dressing down. So just kind of be mindful of that. And I'm gonna just tell you from sad experience that I've had many surgeons and have talked to many people about these blocks, these last two blocks. And the surgeons have told 'em to stop doing 'em because they've caused foot drop. And the biggest reason for causing foot drop has been almost always the same. It's been too much local anesthetic, too much volume. When they do a selective tibial block, again, if you are, I can't stress this enough, if you are doing more than five ccs for a elective tibial block, you're doing too much volume and you're gonna cause a foot drop. And if that happens to 1, 2 3 of your orthopedic surgeon's patients, well they're gonna tell you don't do these blocks anymore. And the problem with that is, is now you just limited the analgesia ability that you have for your patients. They, you know, they, you know now, now you're limiting what they can, what they can do, what you can do to help them with post-op pain. That the exact same thing actually happened today at my hospital where the surgeon didn't want us to do posterior tibial because of a bad experience. The patient woke up in pain and we couldn't do anything because of that. And so, so don't, don't let that happen to you do five ccs only if you're doing selective tibial. If you're doing a IPAC block, you can do more local anesthetic, more volume, it just can be dilute. But make sure you're riding on top of those condyles. And the last thing, most important slide is to keep calm and always do a regional anesthetic. Thanks so much for joining us today on this behind the scan webinar on analgesia for total knee surgery. - Alright, well thank you so much Dr Teams, that was a really great deep dive into those knee blocks. It looks like we have a few questions here ready for you. The first question is from Janet. She asks, how much volume do you usually put in the adductor canal and what percent? - Yeah, so that's a great question. So for the adductor canal, just the adductor canal, I do 15 ccs. Again, if you do more than 15 ccs in the adductor canal, you might as well just do a femoral nerve block because it's a canal, right? That's in the name it's going, the local tatic is gonna track up and down the canal. And so 15 ccs is kind of the magic number in the canal when you're doing the saphenous block specifically. Now how much volume do I do for all of it? I actually use 30 ccs total. So how I break that down is I'll do 15 ccs in the canal to get my saphenous nerve. I'll do five ccs to do the nerve avast and then I'll do five ccs to get the anterior fem cutaneous nerves that are right on top of the sartorious muscle. And then, and then I'll do five ccs for a selective tibial, just like we just talked about, you don't wanna do more than five ccs for selective tibial, so you don't, because we don't want to cause a foot drop. So that's how, that's how I break it down. But yeah, 15 seasons, seasons in the adductor canal, otherwise it will track up and you can get a lot more quad weakness from, from femoral nerve involvement. That was a great question. - Excellent. And speaking of abductor blocks, do you place a continuous adductor block for total knees? - Yes. So some of our surgeons like that and so it's, it's actually a great, it's a great way to do it. When I, when I do catheters for, for total knees when I do adductors, the way I do it is, is a little different. I can show you, lemme I'll, I'll actually demonstrate it here. So I'm gonna have you do is put the leg on like this and then we're just gonna induct like that. So how I do it is, so first let's go to what, what we normally do for, for an adductor canal, right? So this is, this is our typical approach. We in a Dr. Canal, this is how, notice how the probe is, is perpendicular to the leg, right? When I do a catheter, right? Well, so let me show you my needle. So my needle trajectory is gonna be like this for just a regular single shot. Okay? Now when I do a catheter, all I do is oblique it. Now when I, before I oblique it, watch my probe and then watch the image when I oblique it. Okay? So if you look at the image, the image hardly changed at all. It didn't, it didn't change a little bit. So let me go back a little bit. So I'm now perpendicular. Basically all that you're seeing that's different is the sartorius kind of broadens out a little bit 'cause you're kind of hitting it more on a long axis. So I'm just gonna oblique it a little bit and then I'm gonna kind of divide it into thirds again. Okay? So this is actually where I'm gonna go when I do a catheter. So, so now my catheter, I go in like this almost at a 45 degree angle to the axis of the femur. Okay? So I'm like this. And, and why that's helpful and why that's important is because, you know, if I want that catheter to slide down into the canal, well if I hit it at this 90 degree angle, what's gonna happen is, is it's gonna, it's gonna need to take a 90 degree turn. Well that's, that's hard to do, right? Your catheter just kinda wants to keep going and hitting up against the superficial femoral artery. But if I'll bleak it a little bit, it can kind of slide down the canal a little easier. Instead of taking a 90 degree turn, now it's taking a, now it's taking a, you know, 45 degree turn, if you will. So this is, this is the approach I go and then this is how I go with my catheter. So that, that's also a really great question because it, it highlights the just little nuances of that. Not everybody does that obviously, but I found that's a cool fun technique to, to, to improve your, your catheter insertion skills for inductor canals. - Alright, next question is why not approach the tibial nerve from the medial approach and avoid the common peroneal entirely? - Yeah, so that, that's, that's actually a really good point. You know, when I initially first started doing that, I actually, I actually did do that and you can, you can actually do that from your adductor canal position. I'll, I'll, I'll demonstrate that here in, in just a second. But there's a couple small, little problems for, with, with that. One is going from the medial side to going from the medial side of the leg to the lateral side. That's actually a lot more tissue you have to go through. So if you have a patient that has a bigger leg, it can actually be a little bit more problematic, a little bit more challenging to find. It's not impossible, it's not, it's, it's easily doable. But when I train people to do this, I try to train to, to be something that can be reproducible and that can be easily seen and visualized. Well, when you do your classic papa till blocks, it's, it, everybody knows what that looks like. You know, that that scans an ultrasound, they know what the common pro nerve looks like when it comes together, but also the, the nerve is a lot more lateral, so it's easier to get to. So I'm not saying that it's, it's, it is a bad way to do it. I'm just saying it's, it's a little, it's a little bit more challenging if you have a lar patient with a larger leg. So lemme kinda show you how you could do that from the menial side. So, so here, so here, here's where, here's where I go for my other canal, right? So if you wanna try doing the other one, you just kind of, you just kind of need a frog legum just a little bit more. And then you go right here in the pop till crease. All right? Now on the right side of your screen is gonna be the, the medial part of the, the medial part of the leg. Okay? And actually right here I can see, I'm gonna pull this up a little bit. I'm gonna, I'm gonna give you an arrow here for you. So this is actually my tibial nerve, okay? And then if I go all the way lateral, that's actually my common pronoun nerve. Now she has, she has a skinny leg. So it's really easily, it's, it's doable. And so I can, I can easily go from here, but, but the tissue I'm gonna have to traverse is a lot more. So in this image here, I'm all the way out to the medial border of her biceps valoris tendon. But notice, I don't see a tibial nerve. I have to go all the way medial here to finally see it. So what problem that brings up is, okay, now my needle's traversing a lot more tissue, but can I track my needle through all that? And that, that's been the problem, especially in someone with a lar larger leg, especially in teaching someone is, again, it's doable. You can easily do it. But the problem is, is, okay, can I track my needle all the way to the very end until I get all the way over here, which is where my arrow is to, to the tibial nerve. Okay, so can you do it? Yes, it's fine. You can do it. But the, the way I've been teaching it has been, you know, find the, the common pro nerve, identify it, make sure you're coddle to the bifurcation. Once you're coddled to the bifurcation, just go under the common prone nerve and then just work your way underneath the tibial nerve to the medial side of the nerve and you, and, and inject there. Likewise, if you feel comfortable, you can take a medial approach as well. That's a great question. - Awesome. Next question is, do you generally inject around the nerve or inside of the nerve for the tibial posterior nerve or the popliteal block? - So, so you don't ever wanna inject inside of the nerve. That's very important. You want to be outside of the nerve 'cause you don't want to cause a neuropraxia. You can technically inject three ccs inside of a nerve and not cause severe, longstanding neuropathy. That's actually what these some clinical studies have demonstrated, but you still don't wanna do that. So when I do a a popal block, I go right where the common perial nerve and the tibial nerve just come together and they're just kind of like barely kissing because the me sheath that covers both of 'em is easily accessible and it's also thin right there. And because of that you can work your way into that sheath and block it. Versus when you do a pope block, when the whole nerve is together, it's really hard to get into the sheath without potentially also causing damage to the nerve. So when we're talking about the, the selective tibial block, again that's just one nerve like that. So it's kind of hard to peel off the sheath. So I just kind of go adjacent to it. Maybe sky, sky into it just a little bit in order to get, to get close to that, that nerve. But again, the, at that point where you're doing a selective tibial block, the posterior genus are branching off. So you're still getting 'em, even though you may not be inside the tibial nerve sheath 'cause they're starting to branch off five ccs is plenty enough to get them as they're, as they're coming off of, of the tibular. - Excellent. And do you have any experience with patients that use marijuana and the regional blocks - Marijuana in the regional? Well, yeah, I, I guess I do. There's plenty of our patients who, who smoke marijuana or use marijuana or use, you know, cannabis oils and all that, that sort of of things. But to say that I know that it's worked better or not, I, I, I couldn't tell you, you know, I know CBD oils kind of a big thing and a lot of people have found benefit for, for pain management. But as far as that for blocks certainly doesn't prohibit me from doing a blocks. But I also haven't noticed that, yeah, someone who uses marijuana got, helps their block last longer or anything like that. I i, I haven't noticed any difference with that. - All right, good to know. What local anesthetic is your choice and what concentration do you usually use? - Yeah, so I, so it depends. Some facilities limit the types of local anesthetics you can use. So some will allow you to use, for example, liposomal bupivacaine. If I can use liposomal bupivacaine for long acting, i'll, I'll use that. If not, then usually ropivacaine 0.5 per percent is, is, is what I will typically use, especially for these types of blocks. If I'm using a catheter, then obviously you can't use, you shouldn't use liposomal bupivacaine, you would use ropivacaine. Usually the concentration of 0.2% as an infusion or 0.125% bupivacaine if you're doing that. And as far as concentration, like I said, if I'm doing a single shot ropivacaine, I'll use 30 ccs a 0.5% ropivacaine. When I do my initial injection, especially if I'm doing a catheter, I'll use that same concentration. If I'm using liposomal bupivacaine, I actually will come do 20 ccs of liposomal bupivacaine and then I'll add 10 ccs of 0.5% bupivacaine and that makes my 30 ccs. And then I'll divide it out how I described it before. 15 ccs for adductor canal, five ccs for the nerve sti, five ccs for the anterior femoral cutaneous nerve, and then five ccs for a selective tibial. In addition, if you decide to, you wanted to do a IPAC block and that's your thing, then I would just add like five ccs of saline to that last five ccs to make 10 ccs in order to get that volume for an IPAC block. That that would be the difference. And I've done that in the past as well. 'cause again, you need, you need a little bit more volume for that. So those are the concentrations and the doses I use of local anesthetic for, for these, for for knee blocks. - Awesome. And then in regards to the IPAC block, should you use that block always in combination with other, other blocks or can you use that I ipac block alone? - Yeah, so the IPAC block is really only going to be there for the posterior ict. And so if you're u if you're do, if you're having a type of knee surgery, so the biggest ones that come to mind are obviously gonna be your, your total knees or any knee surgery, but also an ACL. So if you're doing an ACL or total knee, an IPEC block, IPEC blocks are great for that. But to your question, it is really important to get the anterior gents and those other nerves that go around the nerve or around the knee. In addition, the skin where the surgeons are cutting IE vis-a-vis the A FCN nerves. So, so I don't really see a situation where you would just do an IPAC block and that's it and there's no other thing you would do other than IPAC block. I don't ever see that. I would always combine an IPAC block with an, an adductor canal or one of these other blocks because of what I'm doing. Now, again, if I'm doing a, if I'm doing an ankle, I don't need to do an IPAC block because it's only getting the knee. So I, if they're working on the medial malleolus, I may just do 10 ccs for an adductor canal and 20 ccs for a popliteal to get the lateral maus. So, so yeah, so the popliteal is gonna get your lateral maulus, the, if they're working on the medial mall maulus, you'll need to do an adductor canal block and usually I'll just do 10 ccs for that. But you won't need to do anything else. You wouldn't need to do an IPAC block. - Excellent. And does block for the nerve to the vastus intermedius give you the same coverage as blocking the anterior cutaneous nerves? - So no, it doesn't. So the anterior FMI cutaneous nerves are just that, they're cutaneous nerves. So the cutaneous nerves are gonna get the skin over the top of the knee, which is really fascinating because how I discovered it and how it became part of what I do for my blocks is I was just really sick and tired of seeing patients come to PACU over and over again after doing these blocks, including the nerve di mind you and the selective tube block. And they still would be complaining of pain. And I'm like, and so I, I spent a long time kind of diving in with these patients in PACU and just really trying to drill down what is it, where they're really hurting. And, and what I found out was it was actually the skin, the incision from the total knee. So I initially just did some, I initially just did two cc, 2% lidocaine and right above the incision. And because it worked really quick and sure enough it, it would work. But you can't just do a nerve tosis medias and say that's gonna get the skin because it doesn't, it may get a very small part of the skin just on the medial side, but that's not where the incisions are. The incisions are right over the top of the knee. And so that is where you need to get the anterior F cutaneous nerve. Which this actually brings up one really hilarious point that happened to me today. I was doing my moca minute question today, and I kid you not, the, the question was what read as follows? It said, which of the following nerves in the adductor canal block. Now I want you guys to listen very closely and and, and let me know what what you think about this. It says, which of the following nerves in the adductor canal give the majority innervation to the knee? Is it a the common peral nerve B, the saphenous nerve or c the nerve desus medias? So I picked the saphenous nerve, well modic people disagreed with me and they said it was the nerve Desus medias and I vehemently disagree and I wrote a big, long thing about how that's not right. And based on what we just learned and what we just scanned, the nerve dsis, first of all, A doesn't live in the adductor canal. It lives in between the sartorious muscle and the nerve DSTs medias and is not in the adductor canal. And, and b, the nerves, even though it does give some innovation and analgesia to the knee, it doesn't give the majority because the saphenous gives most of the majority of the anterior gents. So I was, I was really, I was really for clamped about it. I was really upset. So I wrote a big letter of that. So if you guys out there are doing mo committ questions and you see that question come by, just, just grin and smile and, and write a, write a thing to 'em. Say this is wrong. Dr. Teams says no. - Alright, it looks like that's all the questions we have today. So Dr Teams, thank you so much for coming by and talking to us about these knee, knee blocks. It feels like you really did a deep dive on these and I think everybody here learned a lot. So everybody in attendance, thank you so much for coming. We hope you learned a lot and we'll see you for the next webinar. Thank you so much. , plain_text