All right, good afternoon, everybody. All right, we're going to get started. So I'm Roger Liu. I'm from Rutgers, New Jersey Medical School affiliated with. First up is Dr. Jonathan Kirshner. He is currently the fellowship director of Spine and Sports Medicine at Hospital for Special Surgery and Associate Professor of Clinical Rehabilitation Medicine at Weill Cornell Medical College. Next up is Dr. Charnoff, Jesse Charnoff, who also completed the fellowship the year after us, actually. Currently also at HSS and serving as assistant professor along with Dr. Drew Creighton, who was my year. So we're gonna get started, and Dr. Kirshner's gonna get us started. Okay, so my name is Jesse Charnoff. I'm going to be talking a little bit today about the procedures that we may do in the lumbar spine, such as interlaminar and transforaminal epidural injections. I have no disclosures. So the objectives of my section is going to be to discuss the indications, how patients may present goals of epidural injections, as well as procedural pearls, diagnostic value that may or may not be there with epidural injections, efficacy, and safety. And then I'm going to talk a little bit about my approach to how I use these injections in treating my patients. So indications to perform a lumbar epidural injection include lumbar radicular pain with or without a radiculopathy, lumbar stenosis with neurogenic cludication, post-laminectomy syndrome, acute herpes zoster associated with pain, and a patient who has had pain for at least four weeks and failed conservative care or is unable to tolerate conservative care. There are several causes for radicular symptoms. They include disc protrusions and foraminal stenosis, most commonly spondylosis, and in less common cases, tumors, trauma, infection. It's always important to keep the less common causes in mind if a patient does not fit the normal criteria or they're not responding to treatment in a way that you'd expect them to. So a patient will often present with dermatomal distribution of pain. This is the referral pattern that the pain will travel into the lower extremities. They do not always fit what the textbook states is the appropriate referral pattern, and we're going to talk a little bit about that later, that there's literature that states that there is some variation amongst person to person. So we have to keep that in mind and use other aspects of the presentation, which include segmental numbness, weakness, or loss of reflexes to help kind of better navigate figuring out which nerve is involved. For lumbar stenosis with neurogenic claudication, we also will have patients who present with pain in the lower extremities, cramping that's worse with prolonged ambulation and standing, tends to improve with patients who lean forward or sit down. So my goal with doing an epidural injection is generally to reduce inflammation, both mechanical and chemical. It's important to remember that there's no evidence that suggests corticosteroids will decrease the natural history of a disc regression or immediately decrease nerve root compression. My goal with doing this is to reduce pain and improve the patient's function and let the natural course of healing take place. It's really critical to have a good conversation with the patient so that you're both the goals of the procedure are clear and you're on the same page with the patient as this will make a big difference in outcome and patient satisfaction. All right, so furthermore, we're going to be discussing procedure pearls, diagnostic value of the injections, efficacy, and safety. So first, my approach. For epidurals in the lumbar region, we discuss interlaminar, transforaminal, and caudal epidurals most commonly. For this talk, we're going to focus on interlaminar and transforaminal injections. So we like to call the interlaminar a get-to-know-you injection. And what we mean by that is the interlaminar injection tends to be the most comfortable. A transforaminal injection can often be a little bit more painful, particularly if there's significant stenosis. In my practice, I like to be clear with the patients that if they are to do a transforaminal, they may experience worsening pain. Oftentimes a procedure like this could have a patient lose trust in the provider and maybe have some poor expectations going forward. So I like to be clear with them regarding that and then go for the interlaminar first in most cases. Other benefits include multilevel spread and even bilateral spread at times. This can also be seen with transforaminal injections. Technically, it's a little bit less challenging for me. There's less radiation for both the provider and the patient. Particularly if the patient has bad anatomy, this tends to be something that I'll go to first. The transforaminal approach also has been linked with more serious potential complications. So for the interlaminar approach, we'll take a paramedian approach. Preparation is critical for this injection, so looking at the imaging prior, determining the best route that we're going to go, and coming up with a plan. So what I'm doing with my pre-procedure visualization is trying to identify ligamentum flavum, making sure that it's present, there was no prior surgery or procedure, that it's fully formed. I'm trying to identify epidural fat areas of stenosis and ultimately planning how I think an epidural would go, visualizing the procedure prior to going forward with it. So here's a sagittal T1-weighted image, and what I'm looking for here is to look for the epidural fat. So you can see it's going to be bright on a T1-weighted image. You want to go to an area where there's definitely fat that you can identify and ideally more fat. Or less, depending on the degree of stenosis or pathology. You're also wanting to look for ligamentum flavum and looking for any areas of outpouching that may alter this area. There's a study performed by Botwin that identified a statistical significant difference between cephalad and caudal flow with an interlaminar epidural, so it's going to go more cephalad than caudally. And a statistically significant difference between ipsilateral and bilateral flow, so more one-sided. And he found that it was, I believe the number was like 1.5 to 1.8, that it's going to go up in terms of levels. So this is a multilevel injection, but we have to keep in mind that it's not always bilateral as it's often confused as such. We want to be cautious when we're doing these injections in terms of the volume used, because if there's stenosis, you could acutely worsen the stenosis. Other things that I'm looking for when I'm doing my pre-procedure radiographic check is to look at the ligamentum flavum, and this is a good example as to why. As you can see here on the image to the right, there's anterior ligamentum flavum to the ventral interlaminar line, and we'll talk about what that means in a little bit. But the needle is a little bit anterior to where we would ideally see it for an interlaminar injection. But when we inject the contrast, we can see it's perfect flow. So if you are doing the pre-procedure planning, you can anticipate that there may be a little bit of a more anterior needle placement, and it would make you a little bit less concerned. You can also always inject contrast a little bit sooner if you're concerned to ensure that you're still safe. All right, so the technical description, you always want to identify the proper level and then tilt the C-arm to maximize the amount of radiolucent space. Once you have done that, you oblique towards the side of pathology. You always want to check a midline view, which is the bottom right view, to ensure that you have, or an AP view, that you haven't crossed midline as that would throw off your contralateral oblique or lateral imaging. So once you are in either your contralateral or lateral oblique, there are several things that you want to look for. So for me, I tend to prefer a contralateral oblique image. I'll go 45 degrees from the AP view. And as I'm approaching the ventral interlaminar line, which is demarcated there by the dashes, you're going to start feeling for loss of resistance. You want to make sure you're doing this, you know, ideally as close to the line as possible because if you start too far posterior, you're more likely to have a false loss. And too anterior, you could potentially have a wet tap. So if you're going for some distance and you're not feeling the normal loss of resistance as you'd expect, you always want to check an AP to ensure that you're safe, you haven't crossed midline, or there's no other variable that could explain this. So the big debate with interlaminar injections is whether or not you want to use the ventral interlaminar line or a spinal laminar line. As you can see here depicted, this is the difference. The spinal laminar line is going to be with a 90 degree lateral image as opposed to the contralateral oblique, which tends to be around 45 degrees. So Gill did a study in which he was looking for needle visualization and found that with the spinal laminar or lateral view, he was only able to visualize 3 out of 28 needle tips as compared to 22 out of 28 needle tips for the ventral interlaminar line or the contralateral oblique. There's a statistically significant difference there. And without seeing the needle tip, the procedure becomes increasingly more dangerous. So there's several theories as to why people think the lateral view is more difficult to visualize the needle tip, one of which is that due to the anatomy of the anterior spine and the increased kilovoltage required, there's overpenetration relative to the superficial layers making it hard to visualize. Either way, I prefer the contralateral oblique and find that it is a better visualization, therefore safer. So this is another example of what it's supposed to look like in the contralateral oblique view. And as you can see, the needle's approaching the ventral interlaminar line. And as you're approaching, you're going to start feeling for loss of resistance. All right, so this is an image of an MRI in which I performed the real, the measured contralateral oblique angle. So what you're trying to do here is go parallel to the lamina to an interface at the midline and roughly got about 50 degrees. Just to show you how you would measure if you wanted to and kind of the principle behind how we're coming up with these numbers. It wasn't just kind of thrown out. It all had to do with initial studies where they measured these angles and kind of determine the best angle to go from there. All right, and then this diagram helps show if you were to under oblique or over oblique, what may happen to your needle tip. So A is 45 degrees oblique. So where the dotted line is the ventral interlaminar line. So the needle tip is where you would expect it in the appropriate spot for the ventral interlaminar line. For B, it's under oblique. So it's about 30 degrees. And the needle tip is gonna appear to be at the ventral interlaminar line, but it's actually gonna be posterior. So you're gonna have to do loss for a longer distance and there's higher risk of false loss. In C, we have an over oblique. It's about 60 degrees. And when you're gonna be appearing to approach the ventral interlaminar line, you may actually already be in the epidural space. So there's a higher risk of a wet tab. So you wanna keep that in mind when you're doing your angulation and your rotations. Okay, so transforaminal injections. We're gonna talk about this in further detail later in this talk, but this is a, I'm gonna briefly go over it. So this is an image where the superior end plate has been leveled off and now we're obliqued in our trajectory view. We wanna go right under the pedicle in the safe triangle, which we're gonna talk about a little bit more. Just like the interlaminar injection, we always wanna look at the radiographs prior to performing the injection to ensure safety and proper injection is being performed. So in this image here, we see an extruded disc in the foramen. It's kind of squishing the nerve superiorly. So in seeing this image prior to the injection, I may change my route. I may say I wanna do an interlaminar. I may wanna go infraneural. So this could change the planning of ultimately where we're gonna go. I'm also thinking, do I wanna use a particulate versus a non-particulate? And we'll talk about that in a little bit. Is it, should it be a one level or a two level? So all these things need to be discussed with the patient and thought about based on the radiograph and the clinical history. So in talking about the particulate versus non-particulate, this is a study that was done in 2014 looking at the difference between particulate and non-particulate steroid injection and whether or not there was any change in efficacy. As you can see in the top right, on the label of Kenalog or Triamcinolone, it says that it's not for epidural use. So there is that information available that you have to discuss with the patient prior to doing something like this. What happened with this study was that they found that dexamethasone was not inferior to Triamcinolone or Kenalog. It did require an increased number of injections to have the same results as Triamcinolone, but ultimately they found no significant difference. And henceforth, dexamethasone has become significantly more commonly used for these injections. One thing to keep in mind is with Medicare's changing guidelines, there is the potential where there will be an increase in Triamcinolone in Kenalog because in order to repeat an injection within three months that has not provided benefit, you either have to change the level or change the inject date. So there is the potential that Kenalog injections or particular injections will rise again. And it's gonna be interesting to see if there's new studies done examining this further. Another thing to consider when doing a transferaminal epidural steroid injection is how far is the medication gonna flow? So we spoke about for the interlaminar that it does flow more cephalad than caudal. Dr. Fuhrman did a study in which he found if using four mLs of contrast, you're able to get to the superior intervertebral disc and inferior aspect of the intervertebral disc 93% of the time. So this kind of put to rest the debate over whether or not transferaminals are single level or diagnostic or if they can achieve multi-level flow. Okay, so now we're going to talk a little bit more about that selective nerve root block and diagnostic value. OK, so the selective nerve root block. This is something that we see all the time get referred by surgeons and different specialists. And the question is, can you actually do a selective nerve root block? So Dr. Fuhrman did a study in which he was looking for flow of contrast and whether or not it went more than one level or more than one nerve root. What he found was at 0.5 mLs about 30% of the time, it did involve more than one nerve root. So you have to use less than 0.5 mLs of injectate for it to truly be selective. This is important to keep in mind if you are referred these types of cases to have this discussion with the surgeon and the patient. You definitely want to make sure that the surgeon actually does want you to do a selective nerve root block, and they're just not phrasing a transferaminal as a selective nerve root block, which happens a lot. So you want to be really clear with the patient and the referring provider so that you can do the appropriate injection. But it is possible at very low medication dosages. And then talking about efficacy. So there's a big meta-analysis in 2018 by Lee looking at whether or not transferaminal or interlaminar injections were superior. He looked at 10 randomized controlled trials and two non-randomized controlled trials and found that transferaminal injections were superior to interlaminar injections in the short term. So that's two to four weeks, and trended to be superior at about four to six months, although that was not statistically significant. They also found that a transferaminal injection led to more discomfort and adverse events during the procedure. It's important to note that all of these trials used particulate steroid. And ultimately, NASS has come out with a position statement stating that transferaminal and interlaminers, they cannot say one is superior to the other. And for the purpose of doing a steroid injection in the epidural space, both are equivalent in their mind. This is another study that was performed and used as part of that meta-analysis by Dr. Ackerman. So what I like about this study is he compared transferaminal, interlaminers, and caudal epidural injections. One of the common questions that I'll get is, how many injections am I going to need? Will it work? How fast will it work? So what he found in this study is that it required about 1.5 transferaminal injections to achieve benefit, versus 2.2 interlaminers, versus 2.5 caudal injections. So I use these results to help guide the patients into understanding it may take more than one injection. That doesn't mean that you failed treatment, that you're not going to get better, but it could be part of the process. And he also found that transferaminals were more effective as compared to interlaminers, although all patients improved. So with lumbar stenosis and neurogenic claudication or radiculopathy, the general consensus from NASS is that an interlaminer epidural injection is superior to transferaminal, although it only seems to provide benefit for two weeks to six months, long-term data is less compelling. So with these patients, I tend to try to encourage other forms of treatment, including PT, pelvic tilts, different activities that we can modify, like I do with all patients, but really just trying to get on the same page in terms of goals and what their long-term goals are so that we can have a good outcome and a happy patient. So in terms of the safety data, okay, we use contrast, digital subtraction. Digital subtraction is something that we don't talk about in the lumbar spine often. I use it if I'm injecting contrast a little bit prematurely and the area becomes darkened. By using the digital subtraction, you're able to visualize the medication coming out as you manipulate and try to get closer towards the epidural space. We also want to use extension tubing to minimize manipulation. Those are obviously complications that you may incur while doing the injection. So this is a study that was done by the FDA, looking at all epidurals that were performed from 2009 to 2015, and looking at complications that were found. The significant findings here were, there's an increased risk of serious complications in cervical and thoracic procedures as compared to lumbosacral. There was also a statistically significant increase in complications with interlaminar or non-transforaminal approaches as compared to transforaminal approaches, which is kind of counterintuitive to what you would think and what has kind of been pushed along anecdotally for many years. This was a study that looked at about one million epidurals in the lumbar spine. So it's really good data and some of the studies really good data and something to kind of keep in mind going forward. The downs of this study was that they only looked for complications three days after the procedure. So there potentially could be some things missed, but it's definitely compelling data and something to review further. So in conclusion, we want to evaluate who's a good candidate for epidurals. We want to determine the best route for both efficacy and safety. It's important to review the images extensively prior to the procedure to avoid any road bumps or potential complications. And then most importantly, communicate the goals with the patients and discuss realistic outcomes so that ultimately they can achieve them. Thank you. So just a quick plug for you guys. If you guys want to ask questions, open up the app, the AAPMNR app, and then find the session and click Q&A. And I apologize for my voice. I'm starting to lose it, so we'll see. All right, so. The clicker okay, okay, so all right, so it's all wait. That's the wrong lecture This was entirely planned everyone just to give you a mental break Uh, yeah, yeah, it's the luapmr2022 at the very bottom, the second link. Lower, lower, lower. There it is. Thank you. All right. No disclosure. So, um, my portion of the talk will be going over supra-neural versus infra-neural transforaminal epidural steroid injections and their approaches. We're going to start, uh, by discussing procedure planning, uh, certain considerations when we're, uh, with regard to anatomy and imaging, and also some clinical pearls. And we will have time to hopefully go over some common needlecraft techniques to adjust position, um, and also discuss cases of each, why one technique may be your plan A, although we should always aim to have more than one plan for every injection we do. So just a brief review. Um, Jesse touched on this a little bit earlier, uh, the supra-neural approach, there are some, some nuances, you know, uh, it's, it's a little different than the actual sub-particular or retro-neural approach. And the real difference is how anterior your needle tip will end up. So if you are doing a sub-particular approach, your needle will be above the nerve, but you're aiming for the floor of the intervertebral foramen. But on that floor, if you look at the top right corner, you have the spinal canal artery just sort of hanging out there. So it does increase risk of you encountering vasculature there. If you're retro-neural, you're just hanging out in the back of the foramen, so that's pretty safe. But a lot of our patients, they have facet arthropathy, they have redundant capsules. So a lot of times, if you're retro-neural, you may end up in the facet joint. So the supra-neural approach, by definition, is kind of like splits the difference. You're aiming for the middle of the foramen above the nerve, the middle one third specifically. So the advantages of this injection is you're targeting the same triangle, bordered by the descending spinal nerve, the pedicle, and the lateral border of the vertebral body. And you will likely avoid the spinal canal artery, but a disadvantage here is that you may not avoid the radicular artery, which is a branch of that that courses with the nerve. Your target is the chin of the so-called Scotty Dog. So a lot of fellows and trainees, they have a lot of exposure to this particular approach, so we should all be familiar with that. So how you do it, you first obtain a true AP view, just a brief overview on that. A true AP is where the superior end plate of the level that you're injecting at is centered, or via cephalic caudal tilt, the borders are very crisp, and also the spinous process is equidistant between the two pedicles. After you achieve that view, then you oblique to the ipsilateral side, the affected side, and it's important to note that the more medial you oblique, the more medial your needle tip will go more quickly. And the less oblique you are, you'll end up more ventral than medial. So always consider that. And once you've placed the neocovaxial and everything looks perfect, then you confirm with AP and lateral imaging. So True Lateral Imaging, Waring published an article in 2020. He published this based on RFAs, but really the same maneuvers and the same concepts apply for any injection to obtain the true lateral view in both the lumbar spine and the cervical spine. So in the top row, you see that the superior articular process and the pelvic lines are not really superimposed very well. And it appears that one is in front of the other in the AP dimension. And to correct for this, you would oblique the fluoroscope. In the bottom row, you see that the end plate isn't squared up, and the pedicle, one pedicle appears above the other pedicle. So in this dimension, you would do wigwag to correct. So you're basically trying to maximize overlap between four structures, the pedicles, the pelvic lines, the superior articular processes, and also the end plates. So our first case here is a super neural case. A 46-year-old male comes to you, classic right L4 radiculopathy. You perform an X-ray of the lumbar spine. It shows five non-rib-bearing vertebrae. And so the labeling is relatively, you know, easy. And you do observe that there is severe disk space narrowing, L4-5 and L5-S1. So the MRI, are we able to play the video here? Or, okay, it's okay, don't worry about it. So the MRI shows that there's a possible annular fissure. Basically the video here, it oscillates between two cuts, a little higher and a little lower. So the left image you see, once we play it, you know, you'll see the superior cut, you're able to see more of the annular fissure. And the inferior cut, you know, you kind of see the T2 hyper-intensity there too. And you also see that there's facetal arthropathy, ligaments played by hypertrophy, and also pretty significant lateral recess stenosis as demarcated by the two arrows. All right. Thank you. And we'll do the next slide. Good. All right, so this is just a still. So let's play this one. So here, you know, typically when you do the approach, you don't want to go too medial. So typically we learn it's six o'clock on a pedicle, not more medial than that. But if you actually aim for six o'clock on a pedicle here, you see that the nerve was descending there, and it's actually very, very close to the pedicle. If you aim a little bit more lateral, you have a lot more room to work. So that's one little pearl there. All right. So just a still there to recap. On the top images, the L4 nerve is exiting. It's pretty close to the pedicle if you're aiming for midline or mid-pedicle. So the six o'clock position corresponds to the green dot on the AP image in the bottom right corner. If you go a little more lateral and you plan for this, then you aim for the red dot. So once your needle tip reaches that position, then you can check for your contrast flow. It's also important to note that this is a right-sided injection. So what we define as three o'clock is lateral and nine o'clock is medial. It's flipped if it's a left-sided injection. So in terms of where to mark. So now you've obliqued, all right, and you're trying to pick your target. We should always keep in mind and not forget that the more you oblique, the more lateral the actual midpoint of the pedicle will project. So this image with a lot of trig is taken from the SIS guidelines. And basically the way I understand it is, you know, through cucumbers, let me make a salad. So if you cut straight up and down, it'll appear circular, but if you cut in an angle, you'll see more area, more surface area. So the more oblique you are, the wider it is, the apparent width of the pedicle. And so the more laterally you will end up projecting at six o'clock. So what you may think the red dot is, it may be at like 530, it's really at six. And of course, I mark a little bit more lateral to that because with me, residents do injections, so we want to account for, you know, user error. So let's drive our needle. So take my word for this, when I placed the needle, it was perfect. And then my resident just sort of pushed me out of the way, did an adjustment, and here we go. So what would you do in this situation, all right? So just to touch upon some of the pros that Dr. Kirshner shared, this is a 22-gauge needle. It is a little bit less forgiving than the 25-gauge. So by definition, you want to start off being as covaxial as you can, all right? And a typical algorithm is you want to start off with bevel control. And then from there, if it doesn't work, then you can do leverage. And if you have to, employ concavity. But this needle position is just so way off that we are probably better served withdrawing into the sub-queue or out of whatever fascia that we're in, and then going back to beginning of the algorithm, messing around with the bevel control, maybe leveraging. And so that's what we did. So here, we could tell by the way the needle tip is that the notch right now is at 10 o'clock on the clock face. And if we keep on driving, it will just keep on driving more inferior and lateral. But if we rotate the notch to 4 o'clock, it will steer super immediately. That's what we did. All right. So after our correction, we're much happier. But if you keep on driving without making any more adjustments, you're going to go too medial too quick. So you end up having to oscillate between medial-lateral, medial-lateral, making more fine-tuned adjustments. And the thing is, a lot of trainees and myself when I was in training, you know, as you get closer and closer to your target, you want to make your adjustments smaller and smaller. And so we kind of go between medial and lateral. And once we're ready, we're going to check multi-planar imaging in our safety views. So here on the leftmost image, you see the needle tip is kind of pointing down. That's confirmed with your lateral. And you see here that we have a lot of room to go. But if we don't change the trajectory right now, that needle tip might hit the nerve. So we're both inferior and lateral, and we're also posterior as well. All right. So where is the needle tip? It's inferior, lateral, and posterior. So we already know what we want to do. We want to turn the needle tip upward, you know, closer to our target. But here's a little nuance. Where the needle tip is right now, we can do it one of two ways. You can either rotate clockwise or counterclockwise. Because it's posterior, if I rotate counterclockwise, it'll bring the needle tip a little bit more anterior, and it'll increase the odds of us contacting nerve. So what you may want to consider is rotating clockwise and then bringing the needle tip up that way, because then it'll be more posterior on the way up. So we did that. We approximated our target. You can see how we did. Okay. So here we see that we're in a midforamen, middle one-third. We give contrast there. It's epidural. We're pretty happy. So on to the next. And this is a brief review of the infraneural approach. It's also known as the retrodiscal or preganglionic approach. So here, instead of the safe triangle, we're actually looking at Kamben's triangle, bordered by the superior end plate of the subjacent vertebral body, the exiting nerve. And there's some debate. Some people use the descending nerve root as the third border. But really, for the procedures we do, I think it's probably better just to call the SAP that border. So advantages. Theoretically, it's safer for avoiding the radicular artery and spinal nerve. But a disadvantage is, I mean, if you look at the image there in the fluoroscope, I mean, that's pretty similar to how you access a disc. So you can encounter the disc earlier. You can do a, you know, you can, and that can be pretty painful for the patient if all of a sudden they feel you entering the disc, all right? So for here, I would say if you're a little bit less experienced, maybe get your safety views a little bit earlier. So the steps here. You want a true AP, but there's a little bit of a distinction here. You want to square up more so. You want to prioritize the superior end plate of the subjacent vertebral body because your needle will be at the lower part of the foramen instead of the inferior end plate at the level that you're injecting. And of course, you will therefore oblique. You want to roughly bisect the width of the vertebral body, and your target is the junction of the superior articular process and the superior end plate of the subjacent vertebral body. And that's what you confirm via AP imaging. All right. So our first case of the infra-neural approach, you have a 29-year-old female. She comes to you. She has what looks and smells like an S1 radiculopathy, you know, down the posterior, that's where the thorabotic thigh, calf, and heel. X-ray though shows six non-rib-bearing lumbar type vertebral bodies. So you're looking at a lumbarized S1 vertebral body. The question here is, are you really sure which nerve root is involved, right? What is causing her S1, quote-unquote, type of symptoms? Is it the exiting nerve root of the transitional segment, or is it what we would define here as S2, the nerve root below? We can't really be sure. Here you can see that if you look at the MRI in the sagittal and axial views, the exiting nerve root, whatever the label is, is, again, quite close to the pedicle. And the black dot, I know you're wondering this already, but the black dot in the middle of the foramen is actually not the nerve, it's a vein, all right? And so you can see that the nerve at this level is a little bit medial to the pedicle there as it's exiting. So a supra-neural approach is probably not your plan A. If you go infra-neural and you do not stay in the lower one-third of the foramen, you risk encountering vasculature and injecting into the vein. And over here on the right side of the screen, you observe that the vein is kind of curving around and it's curving posteriorly towards you as well. If you stay low and whole and you really aim to be in the very lowest part of the foramen, you avoid the vasculature and there's plenty of epidural fat, as you see in the T2-weighted image, so you have more room to work. And you may actually give the medication that covers both the descending S2 nerve root and the S1 nerve root exiting. So see how we did, all right? So this is a trajectory view, walking off of the lower portion of the SAP or the supraticular process, staying well within the infra-one-third of the foramen. I apologize for the fluoroscopic laterals, they're not great in this picture, but it's supposed to be a pre- and post-contrast. So in the picture to the right, there's going to be a little bit of opacity there. That's supposed to be contrast. This image is really good because, just to recap, this patient has S1 radicular pain, she has a lumbarized S1 reticular body, and so we've effectively given medication to the lateral recess and we've reached two nerve roots at the same time. So that was the first case. The second case, you have a 71-year-old female with a history of L3 radiculopathy. She comes to you and she's seen a person on the outside, she moved from another state, and she's always responded very well to just L3 epidurals. Doesn't know the approach because she's not one of us yet, she's still going to medical school. But basically she fell and she ends up developing more new L4 radicular symptoms in addition to her old symptoms. So X-ray for this lumbar spine shows that there's five lumbar tibial-tibial bodies. You see a little bit of T12, L1 anterior wedging from a previous compression fracture and some bone density issues, but otherwise it looks fairly okay. At the level of her symptoms, L3-4, it doesn't look terrible on an X-ray. You still have preserved disc height and not too much stenosis. On an MRI, however, you see that even though the neuroforamen is pretty patent, which makes that you can really do either approach, at this level you have an annular fissure and tear and even though the nerves exited, that's what's probably causing her symptoms. Can we play this video, please? Or not. Okay. So anyway, so there's annular fissure and tear, but on a sagittal review you also see a caudally migrated portion of disc material, and we'll touch on that in a bit. It's okay. It's okay. We'll just go to the next slide. Yeah. So, all right, so you can see the, okay, good. So here, I threw up the stills from this MRI as well, just to identify some of the anatomy. All right, you see the descending L4 nerve root, you see the annular tear, and you see the exiting L3 nerve root as well, and more caudally you have that disc material that's caudally migrated. This is important to consider because if you're doing the infra-neural approach, you're going to contact that potentially a little bit earlier on, but certainly you see that contacting the descending L4 nerve root. So in terms of what we want to think about before our procedure, you know, you still want to stay low, but then perhaps it's prudent to, at the very end, make an adjustment to bring the needle tip a little bit more superior to see if we can get better flow because, you know, really low in the frame end, there's enough stenosis to potentially hinder flow. So let's see how we did. So the picture on the left, you have a trajectory review, also contacting SAP and walked off. And the safety view, in the middle, you've traversed it, but you haven't actually advanced. And then over here, after, you can see it hopefully a little bit, but we've advanced a little bit into the mid-frame end, and we've given contrast. In terms of the epidural flow, it was excellent. This is the, on the left, you see the pre-medication, the post-contrast film, and afterwards you see a post-medication washout film. And as you can see, it went up at least a level, and it covers both the descending exiting L3, as well as the L4 nerve, that's sort of traveling down. The lucency here is actually the disk material. So in summary, we always want to have more than one approach to our procedures, have a plan A, B, maybe even C. We want to consider the anatomy of the lateral recess and a neuroforamen, and also not just the level of pathology, but you want to look at the level above and below, because that might give you options as well. So if you're, if you have significant stenosis at one level, maybe you can go supra-neural, the level below, or infra-neural, the level above. That's something to think about. Also, as we all know, many patients have multi-level, you know, involvement, and lots of things that look very messy on the MRI. If you're not really sure, maybe instead of doing a two-level, supra-neural approach, you can just sort of be more efficient and just do one level that might cover both nerves. And also, so that's that. And so a couple of other considerations for infra-neural, you know, if the, if it involves lateral recess specifically, because the infra-neural approach really is the most direct conduit to the ventral epidural space. And I mentioned that, Pearl, about the severe foraminal stenosis, yeah, if you want to cover both nerve roots, and yeah, that's pretty much it. So a couple of references, specifically Dr. Todd Stiddick for helping me pick the cases, and also Tim Mouse from SIS, who's working as the case review moderator, you know, has a lot of pros that were paraphrased in this presentation. Thank you. All right. Hello, everyone. My name's Drew Creighton. It's nice to meet everyone. I'm just trying to stay on time here. Great talks by all these guys. I was learning as we were going here. So I have no disclosures. So in developing my portion of this, I sort of thought back to when I was starting out as an attending and really trying to sort of think about what were some of the trickier cases even now that I have. And a lot of them involve transitional anatomy, which we'll get into a little bit more. Roger, I know, got everyone already perked up with that, and we'll continue that. And I think that outside of that, S1 transforaminal epidural injections can also be somewhat tricky. So we're going to talk about those two topics or buckets, I guess, and then talk about patient cases that sort of highlight key points with each of those areas. So remember, when we talk about transitional lumbosacral anatomy, we're talking about a segment that either you have a bottom part of the lumbar spine that looks like it wants to be a part of the top part of the sacrum or a top part of the sacrum that looks like it wants to be a part of the bottom part of the lumbar spine. And there's actually a classification system, the Caselvi classification system, that centers around a few things. So whether you have dysplastic or abnormally formed transverse processes, and whether those are unilateral or bilateral is type one. Type two is whether you have incomplete fusion of the dysplastic transverse process with the sacral segment. And then type three is where you have complete fusion of the transverse process with the sacral segment. So just keep that in mind kind of as we're going, that there's been a lot of studies that have been done with this, and this is sort of the formalized way to talk about them. So when we're thinking about the key points with transitional anatomy, it's important to remember a number of things. The posterior elements, so in particular the facet joints, can be dysplastic and even diminutive, which is sometimes helpful in terms of the bony landmarks that you have to traverse. You want to remember that to obtain appropriate numbering, you really have to count from all the way at the top of the spine. So whether that's with an MRI scout view or whether that's with some of the lower dose radiation EOS imaging to look at the whole spine, that's really the most appropriate way to get the numbering. Oftentimes radiologists will look at it and will call the lowermost segment where they see a disc as five one. You really want to keep that in mind, that the numbering is really based on full spine imaging. Dr. Kirshner gave me a pearl as a fellow, and it really sort of stuck with me and was very helpful with these cases, and that was obviously review your own imaging. And when you're sort of thinking through how you want to approach an intervention with a patient with transitional anatomy, obviously take a good history, physical, try to correlate that with where you think is the pathology on their imaging that's causing their symptoms, then go into numbering it versus saying, oh, I've got a patient with L5 pain, now I've got to find the L5 segment and correlate it. It gets kind of muddy that way. So I think to keep things simple for yourself, that's sort of a process that I've found effective and you may as well. And keep in mind, though, the caveat with any of our epidural injections, whether there's transitional anatomy or not, as was previously mentioned, you can have atypical referral patterns from what we typically read about in the book. So this study that was done by Dr. Fuhrman where they injected, they had patients draw out where they felt pain as they were doing injections. What they found was that anywhere from L3 to S1 can give you pain in the back of the leg. So keep that in mind. The other thing to keep in mind is that in patients with a sacralized L5, the L4 nerve root can serve the function of the L5 nerve root. So it just goes back to some of the things we just talked about. So going into doing any spine procedure, the initial image that you usually get and look at is the x-ray. Now with the case that we're about to talk about, it actually was referred to me from a surgeon. So we had a CT scan along with dynamic imaging. So we actually didn't have an AP and a lateral. So this was from a different case. But just to give you an idea of kind of how I'm thinking my way through this whenever we're doing this, you have an AP and a lateral, and you can see here, the picture on the left shows if you count, and I don't want to run over here and jump up and count, but basically if you count, you'll see that there's clearly five lumbar vertebrae. And then at the very end, you sort of see a segment that looks like it could be potentially transitional segment. And then when you look at the lateral view, you notice that the iliopectinal line, which frequently, not always, but frequently goes through the S1 vertebral body is, you can see where the iliopectinal line goes through, but then you see right below that that there looks to be a little bit of a sort of a diminutive disc. And so it sort of gets you thinking that this patient may have transitional anatomy, and you're thinking to yourself, okay, you know, this is my first case ever as an attending. I'm nervous. What do I do? The good thing is that there's another view you can get to prepare yourself before you go in. So this is called the Ferguson or an up-tilt view, and basically this is 25 degrees, 25 to 30 degrees of cephalad tilt. So as Dr. Kirshner said earlier, the image intensifier goes to the head to sort of better delineate that lumbosacral junction and that transitional segment. And as you can see, the picture on the right is that amount of head tilt, about 25, 30 degrees, and you can start to see that you have two big transverse processes there that are joining with the sacrum. So always sort of keep this in mind, and you can do this to sort of get as prepared as possible going in. So now let's dive into a case that sort of highlights a number of important concepts, and I'm going to try to not talk myself in circles with this. Stay with me on this. You'll understand what I'm trying to get as we sort of step through this, but it's a great case. It's a little bit complex in terms of kind of what we have to step through. So 59-year-old female with two-year history of primarily right lower extremity pain in the posterior lateral distribution. So you're thinking classically L5, S1. She had tried or reported L4 and L5 transforaminal epidural injections. So you may think, oh, that's a little weird. Maybe I would have done a couple different levels, but in any event, that's what the patient remembers. They don't know what their anatomy looks like. They don't know about transitional anatomy. They don't know about any of this. So as I was sort of stepping through things, I had already seen the patient examine them, sort of developed my clinical thought. Then I went to the imaging, which I think is always ideal if you can go through that process. And what you'll notice here is that the segment that I sort of identified as causing primarily a lot of the patient's symptoms, you could argue that that looks like an L5, S1. You can argue that that looks like an L4, 5. You see that there's a little bit of a diminutive disc there. And so, but the key is, is that's the segment that we want to address, right? So whether you call it 5, 1 or 4, 5, that's the segment that you want to address. And you can see on the coronal kind of what that looks like. So preparing yourself before going into the procedure, this can easily be utilized to say, oh, wow. So you can see these big transverse processes that are articulating with the sacrum there. So then stepping through this further, I don't know how well that projects. I can't even see the screen. But you can start to see the MRI correlate of what we just looked at here, okay? So important to note that the image on the right is an axial, not a coronal slice, but just gives you an idea of kind of what I was thinking best correlated with the patient's symptoms was what was going on at this segment here, okay? So giving you a sneak peek of what the eventual radiologist report looked like, what you can see here is this line correlates to where we're at in all three planes, okay? So sorry if that's confusing, but it was my best attempt at sort of showing you where we're at in multiple planes in space here. So interestingly, the radiologist report, which we'll show in a second, indicated this was L3, L4, L5. We go to the MRI, and we put the numbers in again, similar story, L2, 3, and that segment that we're identifying as the segment that's causing the patient's symptoms is again identified as L4 and L5, okay? So in my head, I'm thinking this patient told me they had an L4 and L5 epidural injection, and I'm thinking based on this numbering that I would expect to see that they've had an epidural above and below that big transverse process. So just in case you didn't believe me, this is the radiologist report. So they mentioned the transitional anatomy, they mentioned the anterolisthesis, which as we know, whenever someone has an anesthetic segment, you can get pyramidal narrowing at that level. You can also get canal narrowing at that level as well, and that's what this patient was felt to have. Mild central canal stenosis with narrowing of the subarticular recesses, abutting the L5 nerves that were descending, and then was also felt to have some fairly significant narrowing of the foramen causing impingement of the L4 nerve. So it makes sense that someone would want to do an L4 and an L5 epidural injection. But when you look at the imaging, you sort of notice that there's that big, something doesn't look quite right. There's that big transverse process that seems to be articulating, and apologies, we didn't have a lateral image on this to review, we were only given the AP. But this is why it's incredibly important that you review your imaging. It's also very important to think about the fact that these patients obviously may go down the road of doing surgery. So certainly you want to make sure that the right level is being addressed, operated on, and then affected on kind of all of the above, right? So reviewing your imaging is really important. And so the prior interventionalist was calling this L4 and L5. That's fine. You just would want to make sure that there's clear documentation that those were the levels that were trying to be addressed. Oh, by the way, I realize this is different than what the radiologist reported. And just really clearly document that. So I think that certainly in my mind, I'm sort of saying, okay, I've got an MRI report, I've got this imaging now. I think that I want to address the segment above and the segment below the transverse process there. And to be fair, it does look like, you know, what L4 and L5 look like, you know? So I ended up injecting the patient, and for simplicity, remained consistent with the prior intervention procedure, whether or not my internal clock said, well, you know, the report said four and five, and I was clearly documenting, you know, kind of what we were doing. And so we ended up doing, calling it a five and a one. The reason I'm showing this is that this is kind of interesting. So we heard about the classic ways to do epidural injections. What was interesting here was when we obliqued, we were almost 40 degrees of oblique here, and you can still see that, like, we could get around there, but it was like 30, 40 degrees. But there was quite a bit of an opening there with the facet joint. So we were actually able to get through the facet joint, and then you can see sort of the flow pattern there and kind of where we ended up on the lateral. So the key is you don't want to get, you really want to be careful on the AP that you're not getting too medial, of course. So there's more ways to sort of get the job done and get good epidural flow. And then this was what we eventually called the S1. So really important to review your imaging, really important to review sort of the whole case before you're doing an intervention so that everything is sort of clear for best patient care. So speaking of S1 transfer aminals, we're going to go on to that as our next topic here. And these can be tricky, complex, annoying, frustrating. This is one reason why. I think many in the room have been here. This was a lot of effort to get, you know, a number of vascular flows with this patient. But the point is, is that as was discussed, this is a level of S1 that is well vascularized, and very commonly you will get vascular flow. It's quoted as about 30%. Interestingly, I took a look at this study that suggested that placing an S1 transfer aminal with oblique as opposed to on the direct AP resulted in this study an incidence of 11% versus the 30% that's typically quoted. Now the tough thing with this study was they didn't quote exactly how much they obliqued, but the point is, is that the needle was advanced on more of an oblique view versus more of an AP view. So this was a bit of a messy slide that basically sort of shows that the needle, you could argue, may have been a little bit posterior. We advanced it and probably advanced it to a point that was a little bit too far to get good medial spread. So whether, maybe lateral is not the right term, but the point is, is that this needle needed to come more medial, even though if you look at the left side and you see where the framing looks like it is, it looks like it's in a good spot. So again, can be somewhat another reason they can be tricky. And a third reason is make sure you get the right level. You know, I think that sometimes what's tricky is, is that if you don't get the correct amount of head tilt, you can end up in the wrong frame and so you kind of end up at the S2 level. So if you notice there, again, take a look at the iliopectaneal line, take a look at the S1 vertebral body, and you'll notice that the level that looks like was injected was, was, was, was actually S2. So the key things to think about, and this was inspired by Dr. Mouse's talk on the SIS website, and if you haven't, if you haven't seen that, it's fantastic and it's an incredible learning tool and a number of these points were taken from that. And really what he talked about was the value of the ipsilateral oblique versus advancing on the straight AP to avoid what he terms as the bony flange, and we'll get into that in a second. The other thing that obliquing does is it really well delineates the, both the dorsal and ventral foramen and also the arcuate line of AP. He also emphasized that getting a snowman as opposed to a snowman view of the foramen on top of each other as opposed to superimposed can really optimize the angle at which you're entering the foramen and also optimize getting, getting good cephalad flow. Sometimes when you superimpose the foramen, one of the risks is you go through and through into the pelvis, obviously a problem. The second thing is, is that oftentimes you get flow that's too caught at. So, so really talks about the value of, of the snowman. And then the last thing is the utility of the lateral view to make sure that there's no nerve root puncture and again make sure that you're entering the foramen at the, at the appropriate angle. So diving deeper into a patient case, this was a 25-year-old female who presented with one year of left buttock and left lower extremity pain down the back of the leg. So sounds like, you know, classic S1 referral pattern. And then you look at the imaging here, you see a pretty good size disc herniation at, at the L5-S1 level that's impinging the descending, the descending S1 nerve. So this was our initial AP and if we go back to the picture here, you can see the, the angle at which L5 is on and then S1 in relation to that, the end plate. So I'm looking at the superior end plate of each vertebral body there. So we can't even see the superior end plate of L5. So we already know that we definitely need more cephalad tilt here. And so that's what we did, cephalad tilt. And now you're seeing the, the S1 foramen a little bit better, but beware the bony phalange which is hanging outside and, and sort of hanging a little bit lateral and obstructing sort of a direct AP approach to doing this, this epidural here. And those red lines delineate where that phalange is. It's a little bit, ideally someone may be sitting out there saying it's a little rotated. You're right, it is. The spinous process could come a little bit more to the left and, and that's probably why you see it, the phalange a little bit better on the right. But the point is you need to be aware of it and it can be very, very subtle and, and is the reason why going on an oblique sometimes is, is more effective. So now we've obliqued about 10 degrees and you can see how you now have on the left sort of what the initial look is and then drawing in the snowman along with the arcuate line of, of april there clearly delineates the dorsal foramen and you can see the dorsal over the ventral foramen there, okay? Now the other thing to think about too is, is that whatever you're, whatever the floral beam is shooting is directly parallel to it. So ideally the reason that, the reason that the snowman is helpful is ideally you're entering sort of at, at that angle to get good cephalad flow there that you see on the far right picture. If you're, if you're entering too, too much at, at a steep angle unfortunately a lot of times you can, you can advance to anterior and then also end up with, with caudal flow. So on our procedure here you can sort of see the needle was, was initially directed at the, the wrong foramen. We used a little bit of leverage and, and bellow control and now are headed in the right direction here hitting, now touching down on us here, rotating the needle a little bit. Now we've dropped in the foramen and that's the, that's the exact time where you want to switch to a lateral. The reason to switch to a lateral is, is again to make sure that you don't puncture the nerve root and before we get into the lateral picture I think it's important to sort of think about where the nerve root lives. So this is going from medial to lateral and, and again we've got the sagittal image on top and an axial image on the bottom and you can sort of see as we, as we scroll through here really try to key in on the middle top picture and you can see right behind the vertebral body there at S1 where that, that, that darkened black nerve root is coming down there. And so right, right above, right, sorry, right in front of that is, is obviously the anterior aspect of the S1, of the sacral canal. And then you want to sort of envision where the, the, the posterior aspect of the sacral body is as well. So to do that, to do that, you know, you can sort of see here that the red lines are sort of delineating where those two landmarks are. So we advanced to sort of an ideal spot, not too anterior and you want to sort of envision sort of a nerve root step, nerve root step there, advanced and then got good flow. So in summary, epidural injections in patients with transitional anatomy really identify where the pathology is, is really the key. Let the numbering sort of follow that and have a good understanding of the anatomy. And then with S1 transfer aminals, you really want to make sure that the, you take advantage of the oblique, beware of the flange, identify the snowman. You really want to optimize the amount of, of, of head tilt and then utilize the lateral as well. All right. Sorry if I took too long. All right. Thanks so much. So we have some great questions from our online audience. So if you have any questions, please feel free to reach out to us. We'd love to hear from you. And if you have any questions, please feel free to reach out to us. audience and we have the opportunity for those of you in the room also to ask some questions. There are definitely some themes, so I'm going to lump some of those questions together. We're actually going to start with some of the comments. So while Medicare and insurance rules will have unintended consequences, choosing to use a more dangerous particulate steroid based on data Another related question would be, are you aware of any clinical studies that support the new CMS guidelines which prohibit repeat lumbar epidural steroid injections within a three-month time frame? Related to that, if the average for success with injections is 1.5 to 2.5 injections depending on type, why is it such a challenge to get the second injection? a steroid. I think it's an unintentional consequence that is bound to happen because people are going to be looking for ways to do, you know, second injections and there are a lot of doctors who practice during this time period who do feel strongly that they get a better result with particulate steroid. So I think it's just important to be aware of that and then, like the commenter said, to do more research to just, you know, be sure that we're doing the right thing for our patients. And then regarding the question about clinical trials for three months, I'm not aware of anything that says that one is, you know, the way to necessarily go. I know that Medicare has changed that recently. I think it's on us as physicians to put the time and money and energy into proving, if we feel differently, that two, you know, or more is beneficial to then pursue that to prove it and have things changed. Yeah, I mean, in Kennedy's study that Dr. Charnoff referenced, the average patient got better with 1.4 injections with dexamethasone. So we're already expecting that they're going to need more than one and clearly the guidelines are not really allowing that. A second question, there seemed to be conflicting data about the efficacy of transferaminals versus interlaminers. Past studies have shown earlier relief with transferaminals as opposed to interlaminers and one study that was presented today showed that transferaminals are more effective but also more painful. So I'm confused as to why one of the concluding statements was to recommend interlaminers. And then there was another comment, other studies would disagree with NASS that the interlaminar and transferaminal approaches have similar efficacy. Data argues against this, particularly for lumbar disc herniations causing radiculitis. Yeah, so interlaminar is recommended for stenosis patients. I don't know if I made that clear. But in my personal practice, I do use interlaminers and transferaminals. But, you know, it's a case-by-case, you know, evaluation in which way that I would recommend at that point. One of the questions is, I sometimes get referrals from surgeons or other outside providers for epidurals who jump directly to MRI. Does that happen to anybody here? Pretty commonly. So do you get lumbar spine x-rays prior to your procedure planning to evaluate for a transition? It was weird. When I started out, I felt like every one of my patients was transitional. Like, it was happening a lot. So I was actually getting the Ferguson. When I started out, I was actually getting the Ferguson view on a lot of my patients. I've stopped doing that now, because fortunately, we've got coronal slices. A lot of our MRIs that we get, especially if patients get them through our institution, have a coronal slice. So I get a little bit of a look of that lumosacral junction beforehand. But I still think it's not a bad idea if you're concerned. I don't routinely get it, but if I am sort of thinking about whether that may impact the procedure, a very low threshold to order that. Related question for Dr. Creighton. On patients with a high-riding iliac crest, how often do you do an intra-articular facet approach to get epidural at L5-S1? I'll answer for him. Never. Not often. That was definitely a bit rare, but I thought it was somewhat unique. But it's not often I do that. For Dr. Liu, is the infrared neural approach more or less painful, and are there more inadvertent discograms? It shouldn't be more or less painful, but discograms are probably clearly more possible than a supra-neural approach. You should avoid it. A couple of pros I didn't have time to touch upon before. If you put a bigger band on your needle, and you drive, and you sort of hit the supra-articular process earlier, then you are in more control. We always say bone is home. So if you're over a bone, and then you can sort of fine-tune it and be more careful, rather than be out to the side and just risk it. So I would just, maybe if you're starting out, you're a little bit less experienced, hit bone first, and know that you're posterior, and then be very careful. And then get imaging early. It really shouldn't be. I think we're running out of time. So the last question is going to be, what's your experience with lumbar facet synovial cysts and any success with attempting to aspirate or rupture this if it's causing radicular pain or stenosis? So when you rupture, you're always going to risk that. But basically, I haven't done too many in my career. I think, have you at least become successful? Yeah, I mean, usually they're pretty successful. There was a paper done by Greg Lutz out of our institution that showed you're about a third successful the first time you do it. You're about a third successful the second time you do it. And then a third successful the third time you do it. So often, you can do them, but they can be challenging. So I think we're out of time. But thank you so much for everybody's attention and for being here in person and online. Thank you.

lumbar epidural injections

lumbar radicular pain

lumbar stenosis

interlaminar injections

transforaminal injections

diagnostic value

efficacy

complications

CMS guidelines

transitional anatomy

lumbar facet synovial cysts