All right, we need to plan our injection approach. What kind of injection? There's two types of approaches that we do. The first is an in-plane approach, and the second is an out-of-plane approach. In-plane approach, the needle is parallel to the long axis of the ultrasound transducer. So here we see parallel to the ultrasound transducer. So the ultrasound image we get then is we see the length of the needle. We can even see the bevel of the needle. And so the advantages are it's precise. And when we're working around nerves, when we're working around sensitive structures, we want to be in the long axis, in-plane. Out-of-plane, in contrast, the needle is perpendicular to the long axis of the probe. So then what we see is just a dot. And there are some injections that we can only do out-of-plane. And so it's important to learn both techniques. I would say about 80% to 90% of my injections are in-plane, and I try to minimize out-of-plane. Now, one of the biggest mistakes when people start now doing ultrasound guide injections is you have to set the needle perfectly parallel to the ultrasound transducer, and they start out like that. They put it right under the skin. They look up at the machine, and then they advance the needle, and they don't see it. And what happens is when you look up at the machine, all of a sudden, it turns in an oblique fashion. And so as you get started, if you don't have a lot of experience with this, the biggest tip I can give you is toggle your eyes back and forth between the ultrasound machine and looking down, back at the machine, looking down. So in-plane approach, we visualize the entirety of the needle throughout the course. We also see the needle in relation to sensitive structures, structures that are at risk, which is important, and it's more precise. So here we see a knee injection, laterals to the right of the screen. This is a short axis image of the super patellar recess, and we'll get more in the detail with that. And this is a cortisone shot, so I put in some lidocaine in first, and you can see I'm bringing my needle down with lidocaine. And this little hypocoic stripe right here is the interarticular space. And so then I go in with my needle with the injectate in it. I find that space, and I inject. That space would be very, very difficult to hit in an out-of-plane approach. But there are some injections that we can't do in-plane. So like I said before, we need to learn both techniques. So this is a subtalar, lateral subtalar joint injection. To the left is a calcaneus, to the right is a talus, and this is the joint space, 2 millimeters. And so it would be very difficult to turn the probe on the long axis of that and guide it in. And so we only see the needle tip. And so if the needle were to come down and be behind the bone, we may never see the needle. You may be going back and forth and never see that needle. It can be challenging. So oftentimes we do what's called a walk down, is I take the transducer, move it back towards where I'm entering, and do a stepwise fashion and bring the needle down. And so here we see, in contrast to the in-plane approach, here's the needle tip, and I'm stepwise, bring it down, and bring it right into that joint space, and then inject. So in the lab, we should do both. Okay. So now we have an idea of what we're going to do. So now we need to get our pre-injection images to get to the details of our injection itself. So this is a long axis of the hip. Again, we use long and short axis, but this would really be a sagittal oblique view in an anatomic plane. We're demonstrating our target structure. So our target structure is interarticularly. We want to, in our pre-injection images, if possible, get orthogonal views. So this is a short axis of the hip joint. This is the iliopsoas muscle and tendon. And then we want to identify at-risk structures. So here we put our Doppler imaging on, and we see this vessel right here. And this is the lateral circumflex neurovascular bundle. Obviously, we want to avoid that. So nice thing about ultrasound-guided injections, we don't need to take people off anticoagulation like we used to do when we ordered fluoro-guided injections. So we need to pay attention of where the at-risk structures are. So this is a patient. I did a hip injection recently. So we see a thickened anterior capsule here. We see marginal osteophytes of the femoral head. And so again, I'm going to do an in-plane, long axis, in-plane approach. And I usually aim for somewhere at the femoral head-neck junction. But I put my Doppler imaging on, and lo and behold, I find my neurovascular bundle exactly in the path that I would normally put my needle. So that needs to be readjusted to avoid the at-risk structure. Now my opinion is that when we put an ultrasound on a patient, we're responsible for that image. Yeah, you can see the joint, but if you have no idea what the muscles are or tendons are from the skin to that joint, then we shouldn't be doing imaging. We're responsible for it. Now we don't have to know all the gory details, but we have to know the at-risk structure. So this was a patient that was referred for aspiration of a ganglion cyst in the lateral ankle. He'd had this for 10 years, got kicked playing soccer, and now it hurts and hasn't gone away for six months. And so they asked me to aspirate the ganglion cyst. So here's the pre-injection images. And we see, well, yeah, it's dark. Is it fluid? Well, I see some echogenicity within that. This is solid. We put the Doppler on, and it has vascularity in it. So this is a solid tumor. And here, just to kind of show the resolution of ultrasound, so this is the lateral compartment. This is the superficial perineal nerve right here, before it exits through the fascia of the lateral compartment. And so we'll just scan down. We see the superficial perineal nerve, just two, three fascicles. Now it's in the subcutaneous tissue. Then what happens is enlarges, it's a tumor, goes back down. And so this is a nerve sheath tumor or swanoma, something that we don't want to be aspirating. All right, so I'm going to just talk briefly about sterility and local anesthetics. There's been some comments about local anesthetics and the use of orthobiologics. And part of the reason I want to talk about sterility is probably one of the most common questions is what do you do to make this practical? So I use chlorhexidine alcohol solution when I prep the patient. Certainly you could use iodine. A couple problems I have with iodine. One is it stains the ultrasound probe, so I don't like that. Two is the full effect, you need to at least have it dry for three minutes. Well, I don't want to wait three minutes. And three is a surgical literature tells us that chlorhexidine is probably better than iodine on surgical site infections. So for all those reasons, I use chlorhexidine and I sterilize the probe cover. And so if I'm just doing ultrasound guide injections, I don't go crazy. I just put a tegaderm right on top of the probe cover, put a little ultrasound gel and put the tegaderm right over and it really works quite well. You don't lose any resolution of the probe. If I'm doing a more advanced procedure, an ultrasound, then I will use the telescoping cover or the longer cover because I don't want to break sterility with the whole wiring system. What's that? The cord. That's what I meant. Cord. All right. So let's talk about local anesthetics for a minute. We've mentioned that they are potentially cytotoxic and the answer is yes, they are. They are cytotoxic. And there was a nice study in 2014 showing that cytotoxicity is a concentration in time-dependent manner. All right. So every local anesthetic can be cytotoxic if it's exposed to your orthobiologics for a long period of time or in high concentrations. However, there is a differential in safety profile. So as most of you know, ropificaine has the best safety profile. However, ropificaine, it's nice that it's long acting, but the onset is slow. And so it's not the best choice if you want immediate anesthesia under the skin. Intermediate safety profile is lidocaine. The nice thing is it's quick onset and I've stopped using bubificaine and I completely take that out of the equation when I'm using orthobiologics or anything actually in a joint itself. Interesting study also in 2014 looked at the impact of local anesthetics and they used lidocaine and ropificaine again on both needle caliper as well as the local anesthetic and they found that local anesthetic seemed to compromise the therapy of potential PRP. So they looked specifically at PRP. This other study looked at a couple things. So they look at chondrocytes, stem cells, sorry to use that word. And so it appears that local anesthesia, again, in high concentrations can affect articular cartilage. It can affect PRP and it can affect stem cells. Something interesting about this and I'm still not fully on board is they found that PRP is not affected by the caliper of the syringe and they use a 30 gauge syringe in this study. I would like to see more studies because I tend to use a larger caliper syringe when I'm using orthobiologics and I use a lower gauge the longer the needle. So if I'm using a three and a half inch needle or even a five inch needle for large people with hips, I'm using a 20 gauge needle. But this study raises the question, do we really need to do that? All right, the last principle is that we need to document in our images proper needle placement. And so we're often billing for ultrasound guidance and we need to prove that we were where we said we were. And so a single image is fine to take with the needle in its proper place. A video is even better. So here's a video of a hip injection. You can see it's filling up and then right at the end you can see that air distributes. All right, so now we're going to talk about some specific ultrasound guide injections as particularly as it relates to orthobiologics. I'm going to talk about a couple of them that wasn't in the program and particularly the foot in addition to the other ones. In the lab, we'll go over these. In addition, we'll go over some other injections. So I know in the shoulder, we're going to go over the subacromial injection. We can go over a biceps tendon sheath injection, maybe a patellar tendon injection. We can really talk about anything we want to or a lot of good scanners at the stations we are that can guide you through any particular injection that you would want to do. So with the shoulder itself, there's lots of options. And I'm just going to talk about rotator interval or just mention it. And this has turned out to be a pretty cool injection for adhesive capsulitis. And so I'm doing this more and more. And this rotator interval injection is replacing my long end of the biceps tendon sheath injection because in a sense, that's what you're injecting. But then if you also put injectate in the coracohumeral ligament, it seems to be more efficacious with adhesive capsulitis. But we're going to just focus on the glenohumeral joint and the acromiocavicular joint right now. So glenohumeral joint, we go in posteriorly. So it's a long axis. It's a posterior approach of the glenohumeral joint. I typically have the patient lateral decubitus when I do this. And so here we see the ultrasound image. We see the humeral head. We see the glenoid. And we see the hyperechoic posterior labrum. And then this is the interarticular space. And so we're going to come lateral to medial, long axis in plane for this injection. The nice thing is there's really no at-risk structures. So we always double check. But there's really no at-risk structures for this. And so we'll take a look at that. Now again, getting back to the local anesthetics, I'm not going to belabor this point. I'm someone that likes to have the patient experience a positive one, particularly if I'm using higher caliber needles, longer needles. So for larger people or very muscular individuals, you're going to need a 2 1⁄2 to 3 1⁄2 inch needle to get into the posterior glenoid humeral joint. So I will often anesthetize the subcutaneous tissue. And we're going through the infraspinatus tendon. So I will also put a little in the infraspinatus tendon because it's fairly painful. But then I'm not going to put any local anesthetic interarticular. So I'll just stop at the capsule. And then I'll bring my needle down with the orthobiologic in. I'll go interarticularly. The patient generally doesn't feel it. And I'm not putting that orthobiologic at risk with exposure to the local anesthetic. And so here we go with the injection itself. Again, we're going lateral to medial in plane. We see the needle tip right here. I'm going right along the humeral head. And then what you can just see right there, the labrum pushed out as the injectate is going. So you want to see that injectate disappear. You don't want to see it coalesce. All right, acromiocavicular joint. Going back to that original slide I did about the accuracy of palpation guided, it was 50%. So if we have someone who is thin, and we all, I'm sure that goes up to 80 or 90. But if they're not thin, it can be tough to get into the joint. Here's a long axis of the joint. So to the right is the clavicle, to the left is acromion. We see the joint space in the capsule here. And there's two approaches we can take. The most common approach is the anterior to posterior. Anterior to posterior, long axis, so I'm long axis on the joint, but it's an out of plane approach. And so it looks something like this. Again, the left is acromion, the right is the clavicle. We're going to see our needle come right in. That was quick. There we go. And then pushing the injectate right there. But I would encourage you to go beyond this a little bit and consider doing an anterior to posterior, short axis on the joint, in-plane approach. And so we're going to go back to our joint, and now we're short axis on the joint, and I'm on the clavicle. And what I'm going to do is sweep my probe laterally. Now that's the joint space, and now I'm in the acromion. So again, I'm going from the clavicle, and I'm stopped. And then right here, that's the interarticular space. And then we can go in-plane and see the needle the whole time and not have to deal with the out of plane problem. So here is the injection itself. You can see this needle's going right into acromiocavicular joint. I can see the tip of the needle and be absolutely sure I'm in the right spot. So there's a number of joints that we can do this. Now, sometimes you see on radiographs that the acromiocavicular joint is oblique in orientation, and therefore it would be hard to do this. So again, it's nice to be able to do both techniques. All right, going down to the elbow joint, two places we can inject interarticularly. The two common places, the radiocapitellar joint laterally and the posterior olecranon fossa. Just for a second, I'm going to talk about the posterior olecranon fossa. It's the place that's easiest to aspirate fluid from the joint. And so when I am asked to aspirate fluid, question septic joint, question inflammatory arthropathy, typically I'll look in the posterior fossa. This will be large. I can stick a needle down there. A little bit challenging. So this is where we have to do a standoff. And so I'm going to go lateral to medial, short axis, and go right along that edge of the olecranon to get into the actual interarticular space. I go lateral to medial rather than medial to lateral because I don't want the ulnar nerve at play there. So here's a patient from a couple weeks ago, actually. I was asked to inject. You can see osteoarthritic changes in this individual. And so my pre-injection images, I'm looking, and this is the radial head on the left. This is the capitellum. This is the long axis of the radial capitella joint. We got a loose body there. So certainly a possibility to go in there and aspirate and or inject. I'm going posteriorly to the posterior fossa, and no go. Pretty steep angle here due to bony hypertrophic changes of the olecranon. We got a big loose body there. So I'm going back to the capitellum. So again, two ways we can inject the capitellum. The most common would be a long axis, out-of-plane approach. So radial head to the right now, capitellum to the left, and here's the loose body. And so we got to, in an out-of-plant approach, negotiate that loose body to get intra-articulate. So it can be done with a little practice. But again, if we go short axis on the joint, so now we're at the radial head, and I'm going to scan proximally to the capitellum. That's my intra-articular space. There's a loose body. That's my intra-articular space. So then that's exactly what I'm going to do. Is I'm going to go in, in-plane, short axis, and much easier. Takes a little practice. All right, going down to the wrist joint for radiocarpal joint injections. Just going over the sonoanatomy briefly. We see on long axis of the wrist joint, the radius. We see the acoustic contour of the lunate and the capitate. So with this image, which corresponds to this radiograph, we can see the proximal dorsal synovial recess, and then there's a mid-carpal recess. So our aim is usually the proximal dorsal synovial recess. So we're going to go short axis on that, and here we see it. So we see the scaphoid, we see the lunate, we see the dorsal scaphalunate ligament, and as an aside, I think ultrasound is the best test for dorsal scaphalunate ligament injury, because not only can we do dynamic studies, we can see the individual attachment of the fibers. But another talk, so here we are at the dorsal proximal synovial recess, and that is our aim. What's at risk? A couple of things at risk. One is the superficial veins. So a lot of individuals will have very large veins on the dorsum of the wrist, and second is the fifth branch of the posterior interosseous nerve, and those who do denervation procedures are familiar with that nerve, and next to the nerve, there's an artery. So that's what we want to avoid. And so again, we can go long axis, out of plane, or short axis, in plane. So again, short axis, in plane, long axis, out of plane. So here is long axis, so radius is to the right, this is capitalum. Now we don't see the lunate here, because I'm actually taking the probe and moving, starting more laterally than my target, so I pick up that needle earlier. So here's the needle coming down, I'm marching down that needle, moving the probe, now we see the lunate, now I know I'm interarticular. So in this particular ejection, what you can do is, and when you practice this in the lab, you can try an out of plane approach and just rotate it 90 degrees, and then you'll get familiar with the in plane approach. And here's the in plane approach on a different person, he had a lot of synovitis, it was not inflammatory synovitis, it was more related to osteoarthrosis, it was just much easier to go in plane. So here is my at risk structures, I'm under him, I can see him the whole time, the advantage of in plane approaches, and then you can see I'm filling up the joint. I think personally PRP is very beneficial with basilar thumb arthrosis, with STT joint arthrosis. My experience has been, they do great with the first cortisone shot, maybe the second they come back and now they've only got six weeks relief from the third and then four weeks relief and they're more painful than when they started. And so potentially PRP can mitigate that negative effect of repeated cortical steroids in this small joint. So there's two approaches, I'm not gonna go in too much detail with this, but we can again do this in the lab. Typically, I will do an out of plane approach on these, you can do an in plane approach to the CMC joint, but again, you need a big gel standoff and it's just not worth the trouble. So again, my probe is oriented long axis and there's really not much tissue you have to go through to get into the joint, and so again, I aim for this joint space. Usually I'm going palmar to dorsal for this injection, but you can go dorsal to palmar, just know where the radial nerve is. And I do the same thing for the scaphotrapezial joint injection is the orientation is exactly the same, I would say almost 90% of the time I'm going palmar to dorsal because of the radial artery. All right, going down to the hip joint. We see the long axis of the hip joint here, and so hip injections are typically a distal to proximal long axis in plane approach. You can do a short axis approach, especially in very large patients, but that's a real minority. I would say 99% is this approach. We need to identify the lateral circumflex neurovascular bundle, know where that is. And then we always, as I mentioned before, want to do short axis images. So you do an orthobiologic injection, they don't get any better. You know, you have radiographs and you get an MRI, and on the MRI you see a big iliopsoas thick bursa, and it's embarrassing that you didn't see it on ultrasound because you didn't scan more proximally. So sometimes bursas are more proximal than the joint, and so I've just gotten in the habit on my pre-injection images at least to scan a little bit proximally along the iliopsoas and make sure I'm not missing a bursa. I also like to find the most proximal location of the femoral head-neck region to inject, and why is that? Well, because the anterior capsule of the hip joint is redundant. It actually attaches to the femur close, more proximal to the head-neck junction. And so if we come down with a needle and we're more distal, one, we could go right through the synovial recess and we're not intra-articular, and two is the capsule is more redundant there, so sometimes it's hard to actually puncture the capsule, particularly if you have a larger caliper needle or you're gonna aspirate. So I tend to aim more proximally. And again, it's gonna be based on where the lateral circumflex artery and bundle is gonna be. So again, I don't wanna aim here. I wanna aim either more proximally, but even better, and I've been more and more injecting in this area right here, the femoral head, but I don't like to touch the labrum when I do that. So here's a hip injection. And what I typically will do with orthobiologics is the same thing we talked about with the shoulder. I'll come down with a local anesthetic and I'll anesthetize the subcutaneous tissue. And in this case, sometimes I'll just put a dab on the capsule, but not go intra-articularly, and then go down with my orthobiologic. Now, this is a steroid injection, so I'm actually going in. So I'm going in with my subcutaneous tissue, and then what I do is I go in with a 22-gauge spinal needle here, and before I enter, I always anesthetize the capsule first, then I enter in, and then I do a test dose to make sure I'm intra-articularly, and then I just switch it to, let's say, a steroid injection. If I was doing an orthobiologic, I would anesthetize the capsule, come out, and take a separate needle, and so we don't get any contact to the local anesthesia with the injectate. So here's the injection. This is the same video as before. One caution when anesthetizing the subcutaneous tissue for hip injections, and that is oftentimes you don't see the terminal branches of the femoral nerve. They can fan out very rapidly, and you may not see them, and so if you put a lot of anesthesia in there, you're gonna pick off branches of the femoral nerve. If you put a lot of local anesthesia in the iliopsoas muscle, they may not walk out of there, and so they're your office for a couple hours. So I do enough anesthesia so they have a good experience, but over the years, I've used less and less and be more judicious in its use in the anterior hip. All right, knee joint injections, probably one of the most common injections we're gonna do. I don't, in my opinion, they're not the easiest of all the joints that I do. If they have a joint infusion, piece of cake, but if they don't, it could take a little work. So there's two areas that are the most common areas to inject, the suprapatellar recess, which is where I inject 99% of the time, but you can inject the patellofemoral gutter. So here's a patellofemoral fluid in the patellofemoral gutter. I wouldn't inject it unless there's fluid in there, and you could either go short axis in plane and go right into that, or you can go short axis out of plane and get into that recess. It's closer to the skin, so some people prefer that. I don't for several reasons. It's not always reliable. You're gonna see fluid there, and so I usually go into the suprapatellar recess. So this is the injection I do. This is a long axis. This is a quadricep tendon, and we need to identify several structures. So we see this hyperechoic triangle right here, which is a suprapatellar fat pad. We also see some hyperechoic tissue next to the femur, which is the prefemoral fat, and it's between these two structures that the suprapatellosynovial recess lies. So that's our target, and again, if there's fluid there, it's a piece of cake. Now on short axis, if we take a cross section through there, this is what we see. So we see the cortex of the femur, prefemoral fat. This right here is a suprapatellar fat pad, and this is a quadricep tendon. It's a lot easier if you take your hand and compress back and forth the quadricep tendon, and, excuse me, and you will delineate that suprapatellosynovial recess. So here it is right here. It's hypoechoic, and you can see, here's the suprapatellar fat pad, prefemoral fat, and clearly, this is the interarticular space. We're gonna go lateral to medial to go right into the space. Now I'm just gonna briefly talk about the sonographic signs of osteoarthritis that we see when we do injections, because they're so common, and again, the knee is the most common joint we inject. So one of the findings we see is thickening of the suprapatellosynovial recess. So you can see, again, how thick this is. In a normal person, we barely see this. This person has a joint effusion that demarcated. This is the prefemoral fat right here. We can see bony hypertrophic changes, marginal osteophytes earlier than radiographs, as well as degenerative meniscal changes. Here we see an extruded meniscus as we are comfortable seeing on MR, and then we see that the articular cartilage of the femoral trochlear sulcus, or the patellofemoral joint, is irregular and thin. So again, common findings if you're doing knee injections under ultrasound. So what about the injection itself? Again, I'm gonna find that space by compressing back and forth the sides of the knee, and there's a suprapatellosynovial recess right there. And so if I was doing a corticosteroid injection, I come in first, here it is on short axis here. Here's a demarcation. So I would come in short axis, lateral to medial, aim right for that hypoechoic stripe, and inject. All right, so I just threw this in because we've talked about it a couple times. This is that patient that has inflammatory arthritis, or arthropathy, osteoarthritis that's more inflammatory. They have a knee effusion, and this is exactly what you see in arthroscopy. So here we see on the long axis, thickening of the suprapatellosynovial recess. On short axis, this is all the hypertrophic synovium right here. This is what you see arthroscopically. This is easy. So we go in with an 18-gauge needle, lateral to medial, in-plane. We aspirate the fluid. And if I was using an orthobiologic here, again, I would anesthetize all the way to the capsule, and even a little in the capsule, but not go into the joint. And you know what? If I have a little local anesthetic in the joint, no big deal, there's so much fluid in there, the concentration's gonna be low. After I aspirate it, I'm gonna change the needle, put the orthobiologic on, and inject it. Easy peasy. All right, going down to the ankle, I'm gonna just briefly talk about two injections, a talocrural and a subtalar joint. So talocrural joint, long axis, so the sonoanatomy to be on the left, talus on the right. We see the anterior synovial recess. Short axis, we see the articular cartilage, medials to the left, and we have our anterior compartment. What's at risk here? What's at risk is the anterior tibial artery, and the deep perineal nerve, which is adjacent to the anterior tibial artery. With sonoanatomy, as you scan proximal to distal, the deep perineal nerve will flip over the anterior tibial artery in a lateral to medial fashion. And so some people like to inject this long axis, so it'll be distal to proximal, long axis, in plane. And I never do this injection for two reasons. One, it requires a very aggressive standoff to get the angle that you need, especially if you have some talonevicular joint arthrosis. And two is I don't have the tibial artery and the deep perineal nerve in view the whole time. And so I'm obviously gonna go to the side of it, but I don't know if I'm wandering into the nerve there. So much easier, much better, is a short axis, in plane approach. So what that's gonna be is medial to lateral, short axis, in plane. And it's not a difficult injection. It's one of my favorite injections to do. It's not a painful injection either. And you're looking at the at-risk structures through the full course of the injection. So here's the pre-injection images. Short axis, I'm looking at the Doppler to make sure I know where the anterior tibial artery is. I know the deep perineal nerve is right next to it. And so I'm gonna go medial to lateral here. I'm gonna go right along the superficial edge of the articular cartilage. If you go too high up, you may actually inject the synovial recess. And then you should see it disappear. Another one of my favorite injections. I am gonna mention the subtalar joint because I do a lot of these for our foot and ankle surgeons when they see subtalar joint arthrosis. A little more difficult, but we can certainly go over it in the lab with you if you're interested. And so to find the subtalar joint, we're in an anatomic oblique. So it would be an anatomic axial and anatomic coronal oblique, basically. If you just put the probe in the distal fibular region and orient it 45 degrees, you're in the right plane. And so again, calcaneus to the left and tibia to the right. And this is how it looks. And what I do is then is take this transducer, go proximally until I get this image. And this is what it looks like. And then I'm gonna inject distal to proximal. It's a long axis image, but it's gonna be out of plane. So this is one of those injections that are just out of plane, as I mentioned before, and go right down into it. And we've already gone over that injection. All right, I know we didn't list midfoot, but I just wanna mention that really briefly because ultrasound has been a game changer in midfoot arthrosis. Why has it been a game changer? First of all, radiographs can underestimate midfoot arthrosis and actually MR too. So this is a person with lateral midfoot pain, normal X-ray, normal MR, and ultrasound shows that he has some early midfoot joint arthrosis. Pretty clear, this is exactly where he's standing. He was diagnosed with cuboid subluxation. Secondly, many patients with midfoot arthrosis have multiple joints involved. So you can use the ultrasound probe to find a joint that's most symptomatic. And third is that going back to our table of accuracy of injections, midfoot joints were the lowest on the list. So three good reasons to use ultrasound in the midfoot. And again, in our institution, the ability to do orthobiologics here, both the diagnostic with ultrasound and use orthobiologics and mild to moderate has been a game changer. So something to be aware of with the midfoot, these are not all individual joints. So they're joint complexes. And so if I'm injecting the second, so one of the most common areas of arthrosis is the second, third TMT joint. So I don't have to specifically inject into each joint. And in fact, in the state of osteoarthrosis, many of these will interconnect. So this is a fluoroscopic injection in a patient with osteoarthrosis. And you can see basically dye going completely across the tarsal metatarsal joint and into the navicular cuneiform joint. And so ultrasound guidance is the same principles as we've been talking about with these small joints. At-risk structures are basically the dorsal pedis artery. Occasionally, the medial branch of the deep perineal nerve between the first and second metatarsal can be large. And so I will look for that if I'm in that area. But otherwise, as long as you know where the dorsal pedis artery, you're good. So here's a Taylor navicular joint injection. Again, I'm scanning back and forth, short axis to find the interarticular space rather than doing it long axis out of plane. And then here's the injection in, very similar to the AC joint that we talked about. And then here's a second TMT joint. This was an injection from last week. And so what I decided to do was start out, and I went out of plane. And so, again, it's the short axis images that are going to allow us to see the dorsal pedis artery. So when I was in the middle of this out of plane, I turned it and went in plane just to show both. Here's the dorsal pedis artery beating and going in in plane. And when I injected this, you saw injectate just basically go throughout the tarsometatarsal joint. I scanned laterally and I can see injectate move laterally.

injections

in-plane approach

out-of-plane approach

nerve injections

joint injections

sonoanatomy

local anesthetics