Good afternoon, and welcome to our session where we're going to share with all of you guys our viewpoints on lumbar joints and pseudo joints. For the next 75 minutes, we have prepared an action-packed agenda. We're going to cover everything from the cranial cervical joints down to the last lumbar sacral pseudo joint. I am really honored to be speaking with my fellow presenters today. Starting us off would be Dr. Amit Nagpal. Dr. Nagpal is so well-educated that it is a huge effort just to fit all of his degrees onto this slide. He's going to be starting with giving us an overview of the understanding of how radiofrequency ablations can help us currently manage facet-mediated pain. Following that, Dr. Rivers is going to come up here, and he's going to help us understand what parts of the spine still remains challenging with our current radiofrequency techniques. Dr. Rivers is exceptionally good at delving into complex concepts and trying to really simplify it so that someone like me can understand. But I'm still a little bit scared because he's going to bring us back to something that I really feared in medical school, which is embryology. From there, we're going to change directions a little bit and Dr. Matt Smook is going to come up. He is the last year's PASTR Legacy Award winner, and tomorrow he's going to actually be giving his PASTR lecture, so he's really going to take us to the height of our session today by discussing the suboccipital joints. And I'm going to come back to the podium and finish us off by going to the very bottom of the spine and talking about transitional anatomies and lumbosacral pseudojoints. Each speaker will talk about 15 minutes. If you have questions, jot them down. You can actually submit them now via the AAPMR event app, and we're going to approach them all at the very end. So with that introduction, I'm going to first introduce Dr. Amit Nagpal. Thank you. Good afternoon, everybody. Presenter, Boo, you said, right? Yeah. Okay, great, thank you. Thank you. If anybody is interested, I had amazing charbroiled oysters a few hours ago. I had to change my shirt because of the amount of butter that I got all over myself, but Drago's at the Hilton, I'm sure everybody already knows, this is probably something that you may not know yet, but if you don't, go try it. Bring a bib or a change of clothes, I would recommend. So today, these are my financial disclosures, nothing relevant to the pertinent talk today. Today, I am going to talk about the current state of radiofrequency ablation and very specifically how we can identify whether we're going to have success when we ablate a joint in the axial spine. And I'm really going to focus on cervical and lumbar spine because there is almost no data on the thoracic spine, which is the big black box of part of what we do. Fortunately, the prevalence of thoracic spine pain is pretty low and so I think it's okay to leave it out today but certainly that's something that we should all be considering research in in the future. And then we'll also look at what data there is for selection and techniques, probably avoid techniques a little bit, but the evidence base associated with performing some of these procedures. Right off the bat, we have some great diagrams of spine pain and the association of where the pain might be associated with particular facet joints. This is from the lumbar spine. Paul Dreyfus has published data and we have the cervical spine as well. But you could find cartoons of all kinds that look very similar to this. Roughly, we kind of know the distribution of pain associated with the particular joints of the back historically and of the neck. But there is no physical exam maneuver with a good sensitivity or specificity for this. We all do facet loading, which is also called Kemp's test, which is also called Quadrant's test, in our clinics primarily, I think, because of two reasons. One is patients anticipate that we're going to touch them and examine them and so there has to be something we're doing to help them through that assumption. And then the second part is insurance companies wanna know most of the time if a facet loading was positive but that's actually never been studied. It may be a very good test. We just don't know. And when we, so the best way to kind of historically or with exam, so there's no good exam, right? But with historically to figure out whether or not somebody's pain is coming from the facets or not really has to do with the prevalence of the disease. So this is a breakdown of all the different studies associated with determining what the prevalence of lumbar facet pain is. And this table broadly identifies various studies to assess the prevalence of such a pain condition. Multiple studies investigating lumbar facet pain and the prevalence, ranging widely between 14 and 44%, but also clearly we know that increasing age increases prevalence when it comes to facet pain. And that can be seen from each of these studies. We also know the prevalence drops lower as the rigor of the block paradigm increases. So that means if you do two blocks, you're more likely to have a lower prevalence in your study than if you did one block. Or if you have some of these studies had a controlled block with saline, which should elicit no pain relief for a patient who has facet pain, those are more rigorous block paradigms and that'll decrease the prevalence data in your particular study. So the prevalence is lower for controlled blocks as compared to uncontrolled, even lower when medial branch blocks are used instead of intra-articular local anesthetic, which is some of these studies using intra-articular facet joint anesthetic. And further, if you increase the percentage of relief that you accept as positive, that will also decrease the prevalence. So for example, if you use 80% pain relief as your threshold, you are now limiting your prevalence to a lower number as opposed to let's say 50% or something like that. Or if you use 100%, then you'll drop the prevalence even further. The positive rate of a single diagnostic block ranges between 27 and 50% if that's what you're gonna do. Now, most of us are doing two because insurance makes us do that at this point, but it may probably be maybe the right thing to do too, maybe not, but we'll talk about that in the next few studies. This is evidence that the validity of the standard you use will affect your prevalence, which will then potentially skew your diagnostic confidence or your prognostic confidence, let's say, in your ablation working. It is clear, so okay, so history might help us a little bit. The prevalence might help us a little bit. Exam may, probably we don't know if it helps us. So let's talk about CT scan. Anthony Schwarzer's group found no correlation in between positive response to local anesthetic medial branch block and CT scan findings of degenerative disease in one direction or another. And that has been replicated subsequently, but this was the original study on this. So CT scan findings of facet arthritis have no bearing on whether somebody has a positive medial branch block. And if I could extrapolate, if you do a very well done medial branch block where there's a small volume of local anesthetic placed on the medial branches in question and no local anesthetic is placed anywhere else and the patient improves, there's really only three options. It's either that the pain is coming from the facet joint because that's what you've denervated or the multifidus because that's something else you've denervated or it's a placebo effect. Or, and then the fourth option is you did the block wrong. Those are the only real, and you put too much local anesthetic and maybe then you denervated the entire dorsal ramus or so on and so forth. And when we study that and compare it to CT scans, there is no correlation. You could have crystal clean facets and have positive response to medial branch block implying that arthritis has nothing to do with facet pain. Steve Cohen's group at Hopkins and USIS found the same when it comes to MRI. This has also been subsequently replicated, finding that no relationship exists between local anesthetic blockade of medial branches and the MRI findings of hypertrophy or degeneration of facet pain. And ultimately, this means that we can't really rely on most of our imaging to determine whether or not someone may or may not have pain that is associated with a medial branch block. I'm being very careful with the way I word that. I think that, so from going forward, I'm just gonna say facet pain, but I think everybody in the room has to agree with me that we are extrapolating the decision that if somebody has a positive medial branch block that we're assuming it's coming from the facets as the most common source of pain. But there are other options, as I indicated earlier. What about SPECT-CT? Raise your hand if you order SPECT-CT scans to look for facet pain. Just the two of us, sir. Yeah, great. What's your name? Paul. Paul and I are the only ones, it looks like. I do this. I don't know why I do it. I looked into, I decided to do a little literature search and decide if I'm doing the right thing or the wrong thing. So this is a study from 2022 in Spine Journal trying to elucidate whether there is a positive correlation between whether somebody has increased metabolic activity in a particular facet joint, in this case in the cervical spine, and the outcome of a procedure in which you inject. Now, the problem is a lot of these studies are done by, I don't wanna say incompetent. What's a better word than incompetent? Inexperienced radiologists who do these procedures outside of the realm of how we probably should do them. And so they mixed, based upon the radiologist's decision, intra-articular facet joint injections and medial branch blocks. And if I go back a couple slides, I can tell you, and we all know the intra-articular facet joint injections have absolutely no prognostic qualities when it comes to whether or not you'll get better with ablation. But maybe SPECT-CT can predict whether or not you'll get better with a steroid injection in a facet joint. We don't know, because that's not really what they looked at here, because they were using this to prognosticate whether someone will get better with ablation. But what they did find is, at a 50% and 80% cutoff pain threshold, that this mix of intra-articular facet versus medial branch blocks does have a correlation with successful analgesia if you stick to the joints that had positive SPECT-CT findings. But the mixed deliberation of the procedure, and also the fact that it's retrospective, and they never said whether it was retrospective and consecutive, it might mean that they cherry-picked patients, so I just don't know. This, I think, is probably the original study that really was well done that looked at this. This was in lumbar medial branches, and unspecified low back pain, the Fryer-Muth study. This was medial branch blocks done with either lidocaine or saline, and everybody was blinded. The physician, to the point that the physician chose clinical intuition to determine which levels to go at. Now, oh gosh, okay, I would say 90% of my lumbar medial branch blocks are done from L3 to L5. Maybe 95%, maybe higher, I don't know. Most of the time, my clinical intuition is it's probably the L3, L4, and the L5 S1 facet, L4, L5, and L5 S1 facet joints, so I'm gonna denervate L3 to L5. But they certainly did other levels in this study, and that's good, because it gives us some mixed data. But ultimately, what they were trying to look at is if you have a positive response to lidocaine, and you don't have a response to saline, coupled with the findings of SPECT-CT, they determined whether or not you would be a true positive, a false positive, a true negative, or a false negative, and then made sensitivity and specificity for SPECT-CT, which is pretty great. And their sensitivity and specificity are .57 and .77, respectively, with an odds ratio of 4.53, and a diagnostic accuracy of .72. So that's a lot of numbers, but I'll just say that that's pretty good, it's pretty good. It's not perfect, it's not great. It's better than facet loading, I'll tell you that, because nobody's studied that yet. It's better than CT or MRI. It's got, there might be something there. So this was published in October of this year. This is a scoping review that determined based on what a lot of us have been thinking, that why don't we know, we talk about this a lot, but there's not good data on it. So they just said, we're gonna summarize all the data from 2000 to 2023 on SPECT-CT for the use of medial branch blocks, and see if there's any associations, which is what a scoping review does. And basically, in the 13 studies that they identified, they found really no associations at all. So thus far, we can't make heads or tails out of whether SPECT-CT is beneficial or not. I know we're in New Orleans. I know this is still hurricane season, but I don't think this is a hurricane, but just in case, it's been good sharing a room with you guys so far. Of course, okay, so this isn't just a slide, it's like a, so we're gonna change our pace a little bit. So, diagnostic medial branch blocks. Which is what we all do, and I just spent all this time talking about using them to determine prevalence, but not necessarily to talk about whether or not they could be used for ablation in a successful manner as a prognostic test. And so, when I talked about that other slide, it was all lumbar, but for what we know from the Lorde study, Lorde and Bardsley and Bogduck, which is an old study now, it probably, maybe it's not still the case, but we at least know from 1995 and some more recent data that cervical axial pain caused by facet pain, remember, there's a sequitur to facet pain, is 50 to 60%, so it's a high prevalence condition. It's a high prevalence condition as compared to lumbar facet pain, which is a much lower prevalence condition, which makes it easier to diagnose. The diagnostic medial branch blocks for the lumbar spine have proven validity, and I probably should change this slide to say prognostic, rather than diagnostic, because we're really prognosticating whether or not, prognosing, one of those, whether you get better with ablation or not. Not really if you've diagnosed the correct cause, but the best, maybe the only study, is that two consecutive blocks with 100% relief gives you pretty good certainty that you'll get better with ablation. That's, nobody's ever studied 50% relief, 80% relief in the lumbar spine, and it's better to be a little more stringent in the lumbar spine, because it's a lower prevalence condition, so you're less likely to find it. It's probably okay to be a little less stringent in the cervical spine, because look, it's 50 to 60%, so that means if the patient walks in the room and says, I have neck pain, it's not going down my arms, I've got a one and two shot that it's coming from the facet, so as soon as I start talking to them, I'm gonna potentially decrease the likelihood that I'm gonna make the right diagnosis, because I've got a one and two shot already that I've got the right diagnosis. I'm gonna keep speaking louder in the hopes that you guys, can you guys all still hear me at this level, yeah, okay, all right. That's quite the ordeal up there going on, so. So ultimately, the importance of this is talking about target specificity. So in terms of validating whether diagnostic blocks are important is that the local anesthetic blockade of the structure in question must fully anesthetize that structure, and only that structure to support the validity of the procedure. So that's why I mentioned not localizing the skin, not localizing the subcutaneous tissue, you're using a low volume of local anesthetic, not using sedation for these procedures which have analgesic properties, because everything else I just talked about goes out the window if you're doing any of those things, because you've lost the target specificity. So when we talk about medial branch blocks in particular, our best method of evaluating the structures is doing it with that type of procedure. We also want to make sure that we're looking at the duration, and again, every study, except for one so far, has told us that the length of action of bupivacaine should be, or ropivacaine, should be longer than the duration of action of lidocaine when we do these medial branch blocks. And that gives us discordant versus concordant responses. Now the definition of concordant versus discordant has to do with just that, that the longer acting local anesthetic has prolonged duration as compared to the shorter acting, but they don't have to be the actual duration of the local anesthetic. So if somebody got 10 hours of relief from lidocaine, but 18 hours of relief from bupivacaine, that's still a concordant response. But if it was inverted, it would be discordant. And every study so far has excluded people with discordant responses from getting the ablation. So we don't actually know if those people actually might have improved. That's interesting to me, because they never got the ablation. We don't know if that still might be a positive predictor for ablation, and we just assumed that discordant response means that you had a negative response. Okay, so in an ideal circumstance, a person would have 100% analgesia, right? But we know that a patient could have multiple pain generators, may simply report improvement due to treatment effect, or they just wanna not disappoint a well-meaning physician, right? That's an option also on the table. So we talked about this, that 50 and 80%, which some of us used for a while, until now insurances have held us to that 80% threshold more commonly. Maybe that's a good thing. We don't know if that works. So there is some data on this. Steve Cohen, again, performed a study in 2008 to assess patients with lumbar medial branch rate of frequency ablation at 50% and 80% relief thresholds. And what he found is that in the patients where he did with 50% relief threshold, but less than 80, so between 50 and 80, 52% of people who went on to get the ablation had greater than 50% relief at six months. But if you use 80% of greater relief, 56% had greater than 50% relief at six months. These are the same, right? These are the same. So this is a retrospective audit, number one. Number two, these were all done with single medial branch blocks, not with two. We don't know what would have happened if he did two. What we do know is this has been replicated in other studies, the Burnham study, Cohen, Van Cleef, Rise, and they showed that single uncontrolled medial branch blocks with any of these thresholds have a success rate of usually about 50%, but 20 to 55% at one year. So that one single block doesn't give us probably what I would consider enough response for us to proceed to ablation, because if you're only getting 50% of people better, maybe that's not so great. Now, Paul Dreyfus and in the Rise study, which I'm gonna also bring up later, showed if you use 80% relief from dual controlled blocks, at one year you've got 83 to 87% relief. If you use 50% relief from the ablation as a threshold, that's much better. So this is the reason that some people continue to argue that it's a good thing that we do two blocks going into the ablation, because you have much better outcomes on the ablation. But the side conversation on that is, but are you limiting certain people from getting ablation who otherwise might improve? So that's a good conversation to have. So the dual diagnostic blockade idea really bridges a gap between effect and consistency, and that is that the repetitive blockade of the same structure in the same patient should achieve the same response. That's consistency. That's really important as a negative predictor, but it's plausible, because it's plausible that the original effect might be placebo and you're limiting placebo each time you do that. So this is a great, unfortunately, unpublished study by RISE. In this unpublished, controlled, randomized, controlled trial, RISE did RFA with four to six lesions, okay, so that's one thing, using a parallel technique for lumbar medial branches. So right off the bat that's a technique that many of us don't use anymore. Success was defined as greater than 50% pain relief from baseline, and he randomized 200 people, which is a lot of people, if you think about it, and he also used placebo-controlled medial branch blocks, too. So the number of patients who achieved greater than 50% relief was higher in the placebo-controlled RFA group, which we would anticipate, because placebo should limit some folks from getting the block, because if they don't get better, then they should get into the RFA, but if they do get better, then you know that that's a placebo effect. The 95% confidence intervals overlap, meaning that there's no statistical significant difference, though, but if they had set a confidence interval at 94%, there was a statistically significant difference. The implication here is that using a placebo-controlled block does, in fact, increase the predictive validity of medial branch blocks as a diagnostic procedure, and this relative increase in validity is based on effect and consistency, which I talked about on the last slide. In this case, it's also based on control, because of the fact that there was a controlled block, which we can't do in practice. It's deemed unethical for us to go in there and inject saline, and if the patient gets better, you're like, ah, gotcha. It was no local anesthetic, and so you can't do that in real practice, but we do know that that probably would help us and get better outcomes if we were able to. To further illustrate the value of control, Dr. Schwarzer's group, once again from Australia, noted that the positive predictive value of an uncontrolled diagnostic lumbar medial branch block was only 31%, and there was just one block, and the false positive rate was 38%. Whereas in Dr. Barnsley and Lord and Bogduck's work, we know, without belaboring this point, that when you do the dual diagnostic blocks, you get much better outcomes. Likelihood ratio is 2.9. That's pretty great for the things we do, and so it's probably going to get you better outcomes in your patients if you limit some of them from getting ablation, but the ones who don't get ablation are not going to get good outcomes because you don't know what you're going to do with them. And ultimately here, I'm going to skip this because this is basically the same thing, but much of this data is summarized here in this slide, which is from the SIS IPSS second edition guidelines. The third edition is coming out soon, and what is clear is that the placebo block is the most valid procedure, but it's not feasible in practice, and comparative blocks are superior to one block for you getting a good outcome with the RFA on the patients you do RFA on, but not for the people who obviously don't get the RFA. You're limiting certain people from getting the RFA, and I leave it up to you to decide if that's good or bad. Lastly, this was a study published by Evan and Patricia and myself and some other folks who are in this panel that was recently studied where we took every patient consecutively who got medial branch blocks in four or five of our practices across the country, got all the data into one place, and I'm over my time, so I'm just going to tell you that it was almost statistically significant that lidocaine lasted longer than bupivacaine, and there's a lot of people, so I don't know what to do with that. I'm going to turn it over to Evan Rivers. I found out today he's an excellent beatboxer. Thank you. Hi, everybody. So Patricia asked me to do a presentation today, and she asked me to talk about some of the issues that we run into when performing these zygoprophyseal joint denervations, and so I'm going to take a few minutes here and talk to you about something that is going to seem a little different to begin with, but I think by the end of this, you are going to have a secret to the way that life works. You are going to have a method that you can use to understand where the medial branch itself is every time, and you're going to know when that doesn't really matter. Finally, I'm going to talk to you about some of the issues you run into and the way that people's bodies are shaped, either during the developmental process or because of degenerative processes. These are my disclosures. None of them relevant, I think. Challenges. What are the challenges we have to zygoprophyseal joint denervation? Number one, segmental anatomy. We have to actually understand what the bits of a person are that we're trying to treat. We have to think about the way that those body parts are grown together, and we have to think about what happens over time as they degenerate. So the first one we're going to think about is the anatomy of the segment. I'm going to put up something on the slide that I think you'll recognize. Oh, wait, no, first, I slipped a secret in here. Does anybody know what the secret formula is? Can you just take a look and tell me? This is the secret to body plans. This is the reason why you have two arms and two legs. This is the reason why you have five fingers on your hand. I think most of us do. It is Hox genes. Hox genes tell every little bit of your body to act like that particular bit of your body. At the top part of your body, you have more activation of the early Hox genes. At the bottom part of your body, you have more activation of the bottom genes. Now, why does this matter? It matters because Patricia is going to be talking to you about pseudo-articulations, which is a dysfunction of some sort of Hox signaling, and Matt Smook is going to talk to you about upper cervical spinal segments. Those happen that way because of Hox genes. Okay, now you have a secret. The secret is how you know that this little chunk of tissue on an embryo is going to look like a thoracic vertebrae or a lumbar vertebrae. All right, secret's over. Now everybody can feel good that they know the secret of life. Here is a lumbar vertebra. And when you look at this, those of you who are familiar with this anatomy will say, this is all apparent to me. I understand exactly what this is. You will see facet joints. And then if I were to highlight this part here, you would say, oh, I know what that is. That is a mammillary process. And the mammillary process is the thing that the multifidus attaches to. And then if I were to show you this little part here, you would say, ah, that is the place where the accessory process is. And the accessory process is the place where the longissimus inserts. And with these two pieces of information, you can say, now I can infer the location of the medial branch. The medial branch always runs between the mammillary process and the accessory process and then curls around the mammary accessory notch and goes into the facet joint and into the multifidus. And then we've got another part over here. We call it the transverse process. This all seems familiar. But let's take a look at a different part of a spine, one we're less familiar with because we don't have good science on it. And it's less commonly painful. How about a thoracic segment? Now, this looks different. We don't see all the same bits. We can identify the facet joints here. But now I want you to say, where is the mammillary process? It doesn't look the same. But there is something here. The mammillary process is the chunk of tissue that the multifidus inserts on. So let's highlight that. That is our mammillary process. What I want you to notice about this, it actually moves over there all the way on to what we would call the transverse process anatomically. Nevertheless, it is the same chunk of segment from an embryologic point of view that the mammillary process is in the lumbar spine. I'll tell you why that matters in a second. This, which we would call a transverse process, is the same thing that the longissimus attaches to. We would call this the transverse process. But in the lumbar spine, it would be analogous to something else. Now we know how the medial branch travels, because it always travels between these two planes, wraps around, and heads off into the multifidus. But those wise among you would say there's something missing here. On that other segment, we had a blue chunk. So where's the blue chunk here? Does anybody have an idea? Think it really loud. Yes, you're getting it. Very good. It's the rib. In the lumbar spine, the thing we call the transverse process is, in fact, the thing that we call the rib in the thoracic spine. This is the same anatomy, the same chunks of tissue, stacked in the same way. In the cervical spine, for those of you who are wondering or worried that it might not be applicable here, it is, in fact. Here's our mammillary process. This is the place where the multifidus attaches. Here is the accessory process where the longissimus, among other things, attach. The medial branch, as you suspected, courses between them. And where's the rib section? It's right there. This has been demonstrated embryologically. And now that you are tickled, we're going to go to the last little bit of the spine. I'm going to blaze right through this, because you've hopefully gotten the hang of it by now. The sacral alum is a rib, every level. OK, so now let's take a look specifically at the thoracic spine. This is one of the first dissections that really looked at the posterior innervation of the thoracic spine. This was done by Nick Bogduck. And you can see how the medial branch wraps way around the top of the transverse process. And we know why that's true. It's because the multifidus attaches all the way out there at the part of the transverse process that we now know is a part of the mammillary process. Subsequent dissections showed us something very interesting. And that is that there is a medial branch, yes, but then there is another little bit in the thoracic spine, sometimes called the descending branch, sometimes called the articular branch, that does not follow the medial branch throughout its entire course. It rather drops from the dorsal ramus or from the medial branch in the foramen and goes directly into the joint. In these circumstances, you can ignore the fact that the medial branch is where it is. Here we can see another illustration where they validated in a different study in a different dissection the location of that thoracic articular branch and demonstrated that it's different than the medial branch. So now we have enough information to say, with some authority, that when we think about the medial branch, we shouldn't think about it as a branch that sometimes goes into the facet joint. We should think about the medial branch as the nerve that goes to the multifidus, like this. And then sometimes, when it's convenient, the articular branch travels along with the medial branch to its end point. The lumbar spine is like this. The thoracic spine is not at all like this. It just goes directly into the joint because it would be very inconvenient for it to pass back through all the multifidus to get back into that joint. If we look at the cervical spine, we can see the same thing. We have two major ways to get in there. Sometimes it's convenient for it to go in from the dorsal aspect of the medial branch. And Dr. Bogdok was able to show us as well that there are proximal articular branches, which is the reason why going very ventral with the lesion is sometimes very important. So now how do we apply that to C7T1? I hope we're all kind of familiar with where the C6-7 innervation is from the C6 medial branch, which I won't go into, and the C7 medial branch, which acts very much like an articular branch if you look at its anatomy. So it's one of those hybrid places where it acts kind of like a cervical spine and kind of like a thoracic spinal segment. And then how do we think about this medial branch? Well, we know now that we don't think about the medial branch here, right? We're going to be thinking about the articular branch. And so how do we plan this out? Well, historically, we would think about this as a medial branch problem. So we're going to go in kind of at midline and scoot off to the side and really hope to catch the medial branch as it goes across the top of the transverse process. But instead, we might want to look at an alternative strategy where we tried to get the articular branches on the side. In however many lesions it is required to cover that foraminal space. What does this look like in a real person? We can talk about anybody who has questions about this particular case. You can find me afterwards. I'm not going to go into the case. But what I'm going to show you is that that bottom needle is one at the T1 level. And that one is a little bit more medial. That's always how the lateral margin of these articular pillars stack. It always comes a little bit more medial. And then if you look at it from the side, you can see that we've taken the needle tip all the way to the ventral border of that articular pillar. And we have placed two lesions in sequence to cover that entire foraminal trajectory. So now what do we do for the mid thoracic spine? It is my contention that you would want to approach this as though you were trying to do an articular branch lesion, much like we just showed you at the last level. So I'm not going to go into that anymore. I need to assert right now for all of you that we don't have good science on this. This is based on our anatomy. This is not based on any clinical data. In the lower thoracic spine is where it gets fun again. Because of course it does. You have to mix what you know about the thoracic spine with what you know about the lumbar spine and see what shakes. So here we go. Here is a T11 and a T12 segment stacked one on top of the other. And so I want you to look at this top part right here. And what does that look like? I know what it looks like to me. It looks like a thoracic facet joint. Very flat, tilted out a little bit. But what does this one look like? I think that looks a lot like a lumbar facet joint. Now I'm going to go to my next step. We're looking at this top one again. I want you to look at that facet joint. And I want you to tell me what in the world is that monstrosity sticking out the backside of that vertebral body? This doesn't match any of our fundamental understanding of what a thoracic transverse process looks like. It doesn't look like a lumbar transverse process. That, my friends, is a mammillary process. That is where the multifidus attaches. And that means that this part right over here, that is an accessory process. That's where the longissimus attaches. Which means, because we know this to be true, that there is a chunk of rib over here and a medial branch running in between mammillary process and accessory process. I contend, though I do not know this to be true, that in the upper segment here, it is very likely that the articular branch has already passed off into the joint because it is convenient for it to have done so. And I don't know what happens in the one below. I really just don't know. So how am I going to think about this? I am going to probably try to lesion this like I would lesion articular branches. Try to strip the side of the facet joint of its innervation directly. And I'm going to completely avoid that medial branch. I think it's a weird spot to try to touch. I think it would probably be a little bit difficult to reach. And I don't think it would help us at all. It would denervate the multifidus without denervating the facet joint. In the lower one, gosh, I don't know. I don't know where that one is. And there are documented cases of articular branches in the upper lumbar spine. So I bet this is a situation where we're commonly missing a few of the branches without really knowing where they are. All right. So now I'm going to move on to something else if Patricia says I have enough time. No, not enough time. So she tells me that we don't have enough time. And so I hope that I have delivered on at least a couple of the things that I talked to you about today. So the first thing I told you is that I was going to tell you something that you could apply to every bit of the spine and understand where the medial branch is. And I hope you walk away with that today. The second thing I told you is I would give you a secret to life. And that's the Hox genes and how it shapes every bit of us from the top to the bottom. All right. So we'll continue the drumbeat of the talks and now head to the suboccipital joints. These are my disclosures. None are particularly relevant to the topic today. But I'm going to talk about suboccipital procedures much like the thoracic procedures you saw just moments ago from Dr. Rivers. This is an area where really good knowledge of anatomy is necessary. This is something that we do when we're more experienced in our approach and with our training. Understanding the 3D anatomy and the relationships is very important both in effective delivery of treatment and avoidance of significant complications that can occur in this area. So that's my disclaimer. So my outline I'm going to talk a little bit about nomenclature and also I guess take an opportunity to touch on embryology for a moment. We'll talk about some of the clinical presentation that's going to lead you to start thinking about suboccipital joints. We'll talk about some red flags to be aware of some injection perils and then I'll add in a few injection pearls and I'm finally old enough now I actually get to talk about pearls and so that's my prerogative. All right so what about the nomenclature? Well the suboccipital joints are not facet joints. The AA joint, the AO joint, these are not facet joints. Embryologically speaking they did not come from whatever part of that blob Dr. Rivers showed you that becomes facets. They came from a different part of the blob that becomes suboccipital joints. Now I don't know where on that graph of O1 and A2 and everything it comes from but just believe me that that's the case. So we don't call these facet joints they are the suboccipital joints. C2-3 facet is a facet joint. So when we're talking about the suboccipital joints we're going to include the C2-3 facet, we're going to include the occipito-cervical junction and the atlanto-axial joint. Now these locations are frequently associated with headache. Okay so people with neck pain and headache that's when you're starting to think in the suboccipital region. This comes from the ipsis guidelines about the diagnosis of cervicogenic headache. I'm not going to read it to you but essentially there's pretty good criteria for when you need to think about somebody having a cervicogenic headache and it essentially is that yeah the neck hurts some and their head hurts some. When do you think about one joint versus the other? Well it can be challenging because there's a lot of overlap in the pain that comes from these locations. You see the diagram here shows the three joints that we're talking about in this talk. The C2-3 joint in red, the AA joint in yellow, overlying the C2-3 joint, and the AO joint in blue. Now this is an amalgam of a whole bunch of people, and nobody, no individual is going to walk into clinic with an exact map of one of these things, right? They're going to have some part of the blue, or some part of the red, or some part of the yellow, along with their shoulder that bothers them too, by the way, right? So it can be challenging to know which one's which. What if we compare the OA joint to the AA joint? Well, in this graph you see in blue the OA joint, and in red the AA joint. Again, I think any individual patient, this isn't going to allow you to determine one versus the other. So a little bit of assistance you can get when comparing the AA to the C2-3, and I think this is probably clinically a little more relevant. This is kind of touching on a pearl, because OA joint problems are less common than AA joint problems, which are less common than C2-3 joint problems. So if you're really trying to tease out one of the two, this is the main tease out that you're trying to do, is AA versus C2-3, okay? And in this one study that looked at these things, there was one feature that was very highly distinctive between AA joint and C2-3 joint, and that is that the C2-3 joint does not involve the ear. Now, only about 50% of people with AA joint said that their headache pain involved the ear. So not involving the ear doesn't mean it's C2-3, but if it involves the ear, now you're thinking it's much more likely to be AA joint, at least according to one study. So how do you kind of try to tease this out? Well, you can use your physical exam. None of, I can't give you sensitivity and specificity of any of these tests. I can just tell you that the face validity of these tests is pretty good, because the OA joint does one thing. It nods up and down. So if it hurts to say yes, that's more likely the OA joint. What does the AA joint do? It does essentially one thing, it rotates. So rotating side to side, saying no, is more likely the AA joint. What about C2-3, extension rotation test, the facet joint test we talked about earlier, is more likely to be that. How can you distinguish between extension rotation and just rotation? There is one test that you can do, and that's the flexion rotation test, as mentioned here. And the reason that's more useful for the AA joint is that when you flex your neck, you stretch the posterior tissues of the facet capsule, causing the facet joints to have this tight capsular structure that's providing integrity to the joint and forcing the joint to sort of lock down. So rotation then becomes limited to the AA joint, which isn't affected by the flexion. And you can test it on yourself. If you just look side to side as far as you can with your head in neutral, you've got close to 90 degrees if you have a younger neck than mine. When you flex your neck completely and then rotate, you've got about half that range of motion. And that's because you've lost the rotation that comes from the facet joints. So flexion rotation test can help to tease between C2-3 and the AA joint, at least in theory. Now, what about prevalence data for the cervical spine? C2-3 is a common joint. Now, mind you, this is from whiplash data. But C2-3 is one of the main offenders when it comes to the likelihood of neck pain coming from a cervical facet. C2-3 is very high on the list. Also, when associated with headache, we know that the prevalence is very high and the likelihood of responding to treatments involving a third occipital nerve is also very high. So two studies quoted here, both of these are post-traumatic neck pain. One showed that patients with neck pain, 71% of them have a headache, all right? So if you have post-whiplash injury and neck pain, you're much more likely than not to also have a headache associated with it. And when neck pain was greater than headache, they actually didn't respond as well as when headache was the predominant feature. All right? And the second study showed the same thing, that a predominant headache with some neck pain is actually fairly predictive at quite a high level of positive response to TON procedures. So when you're thinking about target selection for suboccipital pain and headaches, when headache is dominant, we know from those prior studies that C2-3 is much more likely than C1-2, the prevalence issue. When neck pain is dominant, C2-3 is more likely than C3-4, is more likely than C1-2. What does this show you? This is pearl number one, folks. Don't get fancy here. Start with C2-3, okay? Even if I think, I do my flexion rotation test, I'm like, aha, I think this person has AA joint pain, I'm gonna treat C2-3 first. And do you know why? It's a risk-benefit ratio. What's the risk of a C2-3 or a TON block? It's pretty low. It's a pretty safe procedure. There's not too much going on around there. What about an AA joint injection? Well, it's pretty risky. There's some stuff that can go wrong. So risks are quite different. And what about benefits? If I inject the AA joint and make somebody feel better, and they come back three weeks later and say, well, it hurts again, what are you gonna do? I say, well, I can inject your joint again. And they come back three weeks later and say, well, pain's back, what are you gonna do? Well, I can inject your joint again. I don't have much to do, right? So the benefits aren't as great either. So pearl number one, start with C2-3. All right, so let's just talk a little bit about some red flags. You see somebody with suboccipital pain and some headaches, what are the things you need to look out for? Well, the first thing you should do when you look at any cervical spine radiograph is the following. Assess the structural integrity of the spine, especially as it relates to the cranial cervical junction and the things surrounding the major neural elements or the spinal cord and the brainstem. So the first thing you wanna look at is see that the clivus sits on top of the dens. This is the proper alignment of the head to the cervical spine. So the clivus is that part of the sphenoid bone, the little wedge point that you see at the top of each of these radiographs. And that should be sitting right on top of the dens. From there, you can look at the posterior longitudinal line, the spinal laminar line, and make sure everything looks nice and smooth and normal. And then that's your very first thing that you do anytime you look at a cervical spine radiograph, just by habit, this should be what you do to start with. Because bad things can happen, like this on the right side. You see an issue of cranial settling where the dens is now poking up into the foramen magnum. There's very few things that'll walk into your clinic where somebody can actually die before they leave the clinic. And this is one of them, okay? So if there's a malalignment in that location, it's not something you wanna miss. That's why I say focus on that first. Are there real-world examples where these kind of things are useful to you? This is a patient I saw in my clinic a couple years ago. And I looked at this MRI before I went and saw him in the clinic. And I did my normal exam and everything. And I was about ready to send him out for his physical therapy. And literally, as I was about to walk out the door, he said, oh, I forgot to ask you one thing. Why does it go clunk, clunk, clunk when I move my neck? And I said, well, I don't know. I had examined him already and I didn't notice a clunk. But he's telling me there's this clunk when he moves his head. So I said, well, let's send you for some x-rays before you leave today. We knew from his MRI that he had clippal field syndrome and fusion of C2-3 and C3-4 joints. We also knew that he had a little bit of a pannus up by his dens. But what we didn't know until we got the x-rays was that he had a dens lesion and instability at the cranioservical junction. So this guy got to see my surgeon colleague that same day instead of going to PT and was scheduled for surgery within about a week and placed in a cervical collar between this appointment and his surgery. And did well, came back after surgery. His neck pain was much better and he was doing just fine, no neurologic issues. But something I almost missed, right? And I told you, I look at these things diligently. So you got to be careful. All right, so switching gears a little bit about the injections. I mentioned already that C2-3 is where you want to start. OC1, or occipital cervical junction, is a risky place. And it's risky because of the vertebral artery. Same thing goes for AA joint. It's risky because the vertebral artery is there. But not only the vertebral artery, the fecal sac is close. The fecal sac is close to where we're placing the needle here. And the C2-DRG is close to where we're placing the needle here. So we need to be really familiar with the anatomy. You want to be placing the needle in this one, in the lateral portion of the joint, but not too lateral because the vertebral artery can be out there. It's a good idea to look at your three-dimensional anatomy before you do the procedures just so you have some awareness of where things are before you go in there with your needle. I had a case like that we're going to talk about in a minute. But the vertebral artery can be out of place. It doesn't have to be where it's supposed to be. It can decide that it wants to go somewhere else and an individual. And it occurs at a not insignificant rate. And do bad things happen? Yeah, this patient had a stroke because somebody inadvertently injected into the vertebral artery with particulate steroids. Now, this brings me to another pearl. And that is that when you're doing these things, you should have rules in place. When I was 13 in 1983, my dad brought home a Yamaha YZ80, just like the one in this picture. And he said to me, he said, Matt, this bike's for you. You're going to have a lot of fun on it, but there's two rules that you have to follow. And if you don't follow these rules, then there'll be consequences. Rule number one is you always have to wear a helmet. And I said, OK, that's simple enough. And he said, if I ever see you on it without a helmet, it goes for sale, and you'll never touch the bike again. OK, got that? What's rule number two, dad? And he says, rule number two is always respect the machine. He's like, you're going to ride it. You're going to get good at it. You're going to have a lot of fun. But as soon as you think you're better than this thing, you're going to get hurt. So always respect the machine. That voice of my dad was in my head as I was finishing up my fellowship. And the reports of serious neurologic consequences were coming out from transforaminal injections. And that was a scary time, because we were told prior to this that transforaminals were actually a safer alternative to interlaminar injections, which we already knew had pretty significant risks, rare but serious complications. And so learning that, oh my gosh, this procedure that we were told is safer actually is really dangerous, I need to be careful here. I need to respect the needle. I need to respect the machine. And so I came up with certain rules. One of the rules was that if I'm doing an AA joint injection, I'm never going to inject anesthetic except at the skin, because I don't want to risk putting anesthetic in the vertebral artery. Bad things can happen with that. People can have seizures. And I maintained that rule until Patricia Zhang's first day of fellowship, when we were doing an AA joint injection, on a colleague, a cardiologist that I worked with at Stanford that had this MRI. You can see the stir signal increase on his right AA joint. He had very classic findings of AA joint pain. And so we're taking him into the procedure room for an AA joint injection. And I'm just about to get my needle into the joint. I'm up against the bone, but it hasn't quite dropped down yet. And I can tell he's tensing up and wincing in pain. And I thought, well, I've looked at his MRI. I know where his vertebral artery is. And I'm right up against the bone. There's no way I'm in the vessel. So I'm just going to make it easy on him and drop a little lidocaine in so that I can make him feel better as I finish up the procedure. As soon as I start putting in the lidocaine, he seizes on the table, just like that. And Patricia is there. And she's like, what in the world's going on? And I'm like, well, I think we caused him a seizure from the lidocaine. Or maybe he's dissecting and having a stroke, we'll know in about 30 or 60 seconds. And he comes around, and everything was OK. And he actually wanted to finish the injection. He's like, no, don't take the needle out. I want to finish it. He did research, actually, on local anesthetic toxicity. So he was quite interested in what local anesthetics did in the brain. But yeah, that was a scary time and a scary day. But I broke the rule, right? I stopped respecting the machine. And the point of that story is to tell you that respect the needle. We can always hurt people. Be afraid of these things. Mind your rules. And always wear a helmet out there, kids. Thank you. All right. Next up is Dr. Zhang, who I think still has PTSD from that day. All right, guys. Thanks for surviving the crazy sounds and everything. We're down to our last talk. Is everyone still out there? It's blinding up here, so we can barely see. Let me just pull this up. Presenter view. So my name is Patricia Zhang. I'm on faculty at the University of California San Francisco. And I'm going to be finishing us up by talking about the last segments of the lumbar spine, which sometimes can present as a lumbosacral transitional unit. Specifically, I'm going to be focusing on these lumbosacral pseudo joints. I have nothing to disclose. We're going to start off with a case. It was a foggy morning in San Francisco. And a 37-year-old female landed in my clinic. She's very healthy. She's a dental hygienist. She does yoga. She does Zumba. She works out. She's really fit. She's never had any trouble with her back. But she went on a lovely vacation with her fiance. And they were diving repeatedly into this what I would assume to be beautiful pool. And for the first time, she's been having this persistent left back pain. It's 5 out of 10. And she told me, I wouldn't necessarily have come and seen you, except I went to the chiropractor and got an X-ray. And I was told I had an extra bone in my spine. What's going on? Did the radiologist take counting lessons from my three-year-old who over counts everything, including the four candies that she was allowed to have for Halloween? Or is she superhuman? Is she like one of the members of the Del Solvas family? Where all of them are born with six fully functional finger on one hand. It was due to a genetic mutation. Well, good thing is she brought me her X-ray so I could take a look myself. I think you should be able to see my pointer here. But basically, I did some counting, right? 1, 2, 3, 4, 5. Oh, maybe there are six lumber appearing vertebral bodies here. And when I zoomed in on the X-ray, look at what's there. Where she might be hurting. On the left side, I actually see a pseudo joint. I was highlighting that for you. So how many of you guys, raise of hand, have heard about lumbrosacral transitional vertebrae? Yeah, OK, good. Because it's pretty common, right? So this was taken from a systematic review. And they estimate the prevalence of these LCTVs to be somewhere between 4% to 35.9%. And the authors of this particular study actually did some math, and they calculated the new mean to be 12.3%. Some of these folks are born and blessed with the lumbarization of their S1. So they have six lumbar vertebrae and vertebral bodies. And other people have more of a sacralization of the L5. There is a little bit more tendency in having a transitional anatomy in women. And like what Dr. Rivers had already pointed out, there is some possible association with a Hox gene. I just want to tell you a little bit about something that I truly believe in. We need to be careful how we phrase things, right? If a patient sees on your report that you're calling a segmentation anomaly, that leads to fear, panic. It leads to 15 messages in your end basket about what does this mean, and patients who come into your clinic demanding surgery, like actually what this patient did. But if we actually wrote something more like, ah, you have a transitional anatomy, you're just a little bit extra special, but not destined for pain. That tends to keep people a little bit calmer. You get less concerned messages through your MyChart. So they've done some studies to try to characterize these transitional anatomy more. And you might have heard of the Castelvius classification. So it's divided into four types and tells you a little bit more about what this transitional anatomy looks like. So there's type 1. And here you can just see the transverse process is a little bit larger and wider than normal. So by definition, they're looking for at least 19 millimeters wide. Type 2 here, you can start to see the formation of a pseudo joint there as the transverse process even becomes larger and starts to almost connect like there is a joint there with the rest of the sacrum. Type 3 here, this is complete lumbarization or sacralization. There's complete fusion with the sacral ala. And then there's type 4, which is more mixed. And I'm bringing this up because there may be some clinical implications of this. This was a study actually also out of UCSF with Lorenzo Nardo and Thomas Link. And they looked at 4,636 participants. Out of all these participants, they found that 18% of them had this transitional anatomy. They were looking at what was the rate of low back pain patients and patients without a transitional anatomy. And that's about 54%. And what we can see here is that type 2 and type 4 of the transitional anatomy are actually associated with an increased risk of having low back pain. And they actually asked these patients to report how severe their back pain is on a home kind of developed scale of one is the least severe and three is the most severe. And the math actually shows that especially type 2 and 4, they have an increased odds ratio of having the most severe reports of pain. Some of the pain associated with these lumbosacral anatomy may just be from the joint itself, as initially theorized by Mario Bertolotti back in 1917. So you can almost see some arthritic changes of these pseudo joints. Here is another set of pictures provided to me by Dr. Greta Lebo at Mayo. And so you can see there's a transitional anatomy here on the right. And what we have on the right side of the screen here is first MRI. This is a T1 sequence. You can see right around the pseudo joint there's dark T1 signal, which signifies edema. And then on the CT that accompanied it, you can see that around the pseudo joint there's sclerosis and gas formation, which suggests that there's definitely been some arthritic changes. But the joint, the pseudo joint, doesn't have to be arthritic for it to be associated with pain. So this is a study of quite young patients, as you can see here. The mean age is only 15.7. And they did bone scans on these folks. And you can see that there's 81% with high uptake at articulation between the transverse process and the sacrum. And in 63% of the cases, like this one here, you can see that the only uptake that was abnormal was right around the pseudo joint. And the authors of this paper kind of theorized that, especially when the only abnormality is where it kind of hurts and where we see this pseudo joint, this most likely signifies that some of these pseudo joints undertake more stress and may be more associated with pain. Nowadays, we don't do so many of the single planar bone scans, and we have these PET CTs, which can also, SPECT CTs, which can also show the same thing. Besides just having pain coming from the pseudo joint, the thought process, the theory is that there may be some accelerated wear and tear around the segments, around the pseudo joint and the transitional anatomy, especially because there may be a restriction of movement at the transitional level. It's not a fully mobile level. There could be hypermobility above it, which then in turn leads to sooner or more accelerated degenerative changes. So kind of going to my patient, the one I told you about at the beginning, this is her coronal cuts of her MRI. You can see that pseudo joint right here. What else is going on in her MRI is, if you looked at the sagittal and the axial T2, you will see that this is her L5-S1 disc, and this is probably her hypermobile segment above the transitional anatomy. You can see there's accelerated breakdown of the disc there. There's an annular tear. There's the start of fibrovascular modic type 1 changes, and these changes become more apparent the more left you go, so kind of towards the side of her pseudo joint. So you really can really pick up that mode exchange here right on the left side. And as her disc may even more degenerate there, you can start to imagine that she will get more framinal stenosis and also maybe sub-particular stenosis, and some studies have actually have shown that there's association between transitional anatomy and super adjacent central stenosis as well. And that's what Varga-Wolin and his team tried to do. They looked at 350 patients with low back pain, and in that population, they found 15% had a transitional anatomy, and they wanted to characterize what were the pattern of spinal degeneration around the people who had a transitional anatomy. So they tabulated here the number of disc protrusions, disc degenerations, facet generations, stenosis in patients with the transitional anatomy and without, and these findings weren't super significant except for nerve root canal stenosis. But I think the most interesting part of the study is when they broke it down and looked at what was happening at the super-adjacent levels as compared to the same levels of patients without a transitional anatomy. And you can see, based on comparing these two columns, the rates of disc herniation, disc degeneration, facet generation, and nerve root canal stenosis was much higher at the super adjacent level of people with a transitional anatomy. So kind of as a brief halfway summary here, I just wanted to talk a little bit about what does this all mean. So it seems like some people, when they have axial pain as related to their transitional anatomy, that might be from asymmetric loading and arthritic and or stress changes around the pseudarticulation or possibly the surrounding structures, whether it's SI joint, facet joints, or maybe the disc degeneration. And we can imagine that as a disc herniates and degenerates, it can push on the nerve so it can lead to foraminal and subarticular irritation. And then there's also there's something called the far-out syndrome, which I'm going to talk about in one moment. But before I get to that, I do want to note that in these people with the transitional anatomy, they're much more likely to have an anomalous number of prasecral vertebrae. So in these folks, you might have a slightly different distribution of dermatoma and myotoma changes based on their pathology, because they might not have the traditional number of spinal nerves. So far-out syndrome. How many of you guys have heard of far-out syndrome? This is pretty rare of some people, okay. I have to tell you, I haven't seen one myself, though there are reports of this. But basically a pseudo joint can sometimes become so hypertrophied or maybe just formed in such a way that it can actually start to impinge on the exiting nerve at the extra foraminal area. So you can see on the CT, this is likely the nerve and this big gunking pseudo joint is possibly impinging upon that nerve. And here, too, on MRI of a different patient, you can see the pseudo joint is huge. And this is likely the exiting nerve on the right and the exiting nerve on the left could definitely be impinged around this area. Like managing many things in the spine, we often start with conservative treatments first. And my patient actually did much better after we started to give her anti-inflammatory as needed. We push more lumbar stabilization exercises, especially in the neutral position rather than all the dancing and Zumba and twisting that she was doing as part of her regular exercises. But when that's not enough, we could sharpen our needles because there's a bunch of injections we can do for diagnostic and therapeutic purposes. They can include pseudo joint injections and treating whatever else could be the pain generators, whether it's epidural because there's nerve irritation or the facets where the surrounding SI joint. Pseudo-articular joints can be injected and there's been case reports of the outcomes after these injections through no real good study so far. Just kind of walking you through how to do all these injections. Here is an AP picture here. Is this perhaps where you would want to do a pseudo joint injection? I see some shaking of heads and I would say probably not. I mean, this is indeed the articular kind of joint space that you can make out. But if you were to put your needle right down here, I think you're gonna probably hit the iliac crest. And so often when we do these things, we would contralateral oblique and you can see in this picture we're kind of coming in from more medial and you can see the joint line right there. And it would be nice to put in a little bit of contrast just to make sure you're in the joint as much as possible before depositing your medications. Here is another different picture, but same idea. You basically oblique and make sure you see it well and put the medication into the joint. There has been algorithms developed to help you think through how to manage pseudo joint pain. This one's by Almeida and his colleagues. So basically if you're suspecting that the lumbosacral pseudo joint may be the one causing the pain, you can consider an injection there if the patient is not responding to conservative treatment. If they didn't have even just anesthetic block, you might want to work up some other causes of pain. If you did have some relief, hopefully you have long-term relief from the steroids. And if not, Almeida's group did offer two other solutions. One of them is this possible attempt at RF. So I remember going to a kind of a multidisciplinary meeting within UCSF, and we had this one patient with SI joint, sorry, a pseudo joint pain who I injected and didn't have really good long-term outcome. And the patient's interested in surgery and one of the surgeon was like, oh Patricia, do you think you could just go ablate this joint? And I was like, haha, that's a silly thought. I don't know what I could possibly ablate. And well, I went home and I did a PEMED search and this article came up by Burnham. And so they did in fact have had this one successful report of ablation. So this was an interesting patient who he first got a pseudo joint injection and did have only anesthetic relief. And afterwards, because he was in so much pain and he didn't want surgery, Dr. Burnham and his colleagues just decided they were going to try to do a block, like a medial branch block. So they went in and they basically flooded all the posterior elements of the pseudo joint and the patient actually had complete relief of pain for six hours. So they're like, okay. So they went back and here's where they place their bipolar RF needles. They kind of leapfrogged it because they were trying to do some strip thermo lesions and they were able to kind of burn all above and all below it and the patient actually had complete relief for six, nine months afterwards. So I don't think this is a very well described technique, but this may be something that could be thought of as an option. And for truly refractory cases, there are surgical options. Chang and colleagues had this case series. Here you can see the CT and the pretty cool 3D CT construction of a left transitional pseudo joint. What they would do is they put a glide pin in, they would do a serial tubal dilations until they can get a port in, and under the microscope they can do articular dissection and removal of osteophytes. And Chang and colleagues did say that in their 138 cases that they reviewed, 118 of them had some good results. And so with that I get to my last summary slide. For the first time, my two kids are old enough now that I actually practice my presentation on them and ask them, hey, what do you think? And there were two big feedbacks that they gave me. The first one was if I were gonna make fun of one of my child in front of a room of strangers, apparently both of them insisted that I make fun of both of them equally. And the second thing was apparently mama is a very boring talker. You know, they're teachers, they sing, they dance, and mama just goes up there and I blah blah blah blah blah and use really big words that no one else can understand. So after these very harsh criticisms, I've decided to change up my summary slide. I got this cue from my son, who I hope will one day be as cool as he thinks he is. And I have used the power of chat GPT to turn my summary slide into a rap. So you guys have survived a lot today. Loud noises from things that we don't understand. And as the final thing, I hope you'll kind of clap along with me while I try to rap for you my summary slides. All right. Yo, yo, yo, yo, in life's dance, joints flex and bend. Pivot, hinge, and then we depend. Pseudo joints there. In disguise, mimic the real, but don't mobilize. Not always painful, but quite often there. With types two and four, you have to take more care. Therapy and exercises can do wonders. If that's not enough, there are options in numbers. Injections, ablations, and surgeries as well. We can help our patients feel swell. So let us all give a great big cheer for these joints that we need not fear. When I say pseudo, you say joints. Pseudo joints. All right. Well, thank you. Thank you for making me feel like a rap star. Thank you for attending. Thanks to all of our wonderful speakers who I hope will come up and join us. We might have some questions from both online and if anyone had any questions or comments or complaints about rapping skills, please come up to I think our one microphone up there. Is it possible to turn down the lights? I have a question for Dr. Zhang. Who's your agent? You, Matt. Quick question. So for atlanto-axial joints, what would be your minimum level of crash cart or ED proximity or support in terms of potential complications? Obviously for the seizure that occurred, it quickly resolved, but for a stroke, what would you want ideally? I'll just tell you what we do at Stanford is we do all of our cervical procedures in the outpatient surgery center. So we've got full support and everybody having a cervical procedure gets an IV before their procedure. So that's the approach that we take. But there might be different answers from other folks. All of our cervical epidurals or facet interventions that include C3 or higher receive an IV. And we do them in our outpatient clinic, but we have a full crash cart ready to go. And we will never use any steroid that isn't dexamethasone for such a procedure. We do have one question from the online from Dr. Michael Danto. When performing dual medial branch blocks with 50% or especially with 80% relief, there are going to be false negative response. This is acceptable in a research setting, but 100% of those patients will have a poor response to everything else that we try to do for them. This is not really acceptable. Given the safety profile of RF in the real world, wouldn't it be more reasonable to perform just one diagnostic medial branch block? I hope I conveyed in my talk that that's true. I don't want to use the word reasonable. I just want to say that I wanted to convey that the data is what the data is. I think that some people probably would get better with an ablation that are not getting an ablation if we use more stringent criteria of our blocks. But I also think it's really important, something none of us talked about, is that all of the things we're doing right now are under severe attack by insurance carriers about whether or not we will be able to continue to do some of these procedures. There's bad data out there, like the MINT study, for example, which used perpendicular technique. There were so many problems with that study, but that's one problem with it. If our outcomes are not great and patient-reported outcomes are here and they're going to get more and more ubiquitous as part of our practices, if our outcomes are not great, then we might lose our ability to lose these procedures on anybody, whether they had one or two or ten medial branch blocks. Yeah, I think I'll just add a little nuance to that. I think it's the decision that our society has made at this point that we're supposed to do dual blocks with 80% relief. Medical spending is a limited resource, and maybe that is the appropriate place where you draw the line and say, these are the people that are going to benefit the most. We know they have durable responses and repeatable relief when you repeat the procedure on these kind of folks. So yes, this is what we're willing to allow, and anything less than that just isn't worth it to society. That's the decision that's been made, and I'm personally okay with it. But I understand an argument that we do want to help more people, and maybe there's a better way to help people. I don't know. But these decisions are going to get made, and that's the way the world works. I think we have time for one last question. You, sir. Super. Thank you so much. Just a comment I'll add on that. On the other flip side of two versus one medial branch blocks, there's a study by Steve Cohen, 2018, where they prognosticated one versus two diagnostic medial branch blocks, and they said it didn't really make a huge difference for RFA outcomes at six months, but they also asked the question whether doing two diagnostic blocks would add more cost to the patient. I mean, I come from Canada, so the socialized system works very differently than how it does in the U.S., but just a different flip point to that. Anyways, I'll come to questions. I have two questions I'll appreciate. Now we're talking about the medial branch blocks and RFA is one question, and Dr. Rivers was mentioning about the anatomy of the medial branches. Do you guys have any, like in your practical practice, if you have patients with, you know, how older patients can have degenerative spondylolisthesis, assuming you're doing RFA's lumbar spine for them, are there any precautions you take in terms of your needle placement going exactly for the mammular axillary area for the ligament or not? That's first question. Does this work? Okay. So I think your question was are there any precautions that one should take when doing a lumbar medial branch radiofrequency ablation for someone with degenerative spondylolisthesis? Yeah, grade one or grade two endolisthesis. Gotcha. So the position of the superior articular process at the infra-adjacent level of the listhesis should have the exact same anatomical relationship to the transverse process in the pedicle, so you shouldn't have to make a change to your trajectory with that. If you have a severe spondylolisthesis, then the super-adjacent level is going to be further ventral, and so some of the structures of the infra-adjacent level can be in the way, and you just have to take that into account. I don't think any of the structures are going to be structures that you should worry about. They're not nerve roots or blood vessels or intestines or anything, so that's good. But you can run into interposing bones that can get in your way in that circumstance. You have to take a different angle. The only concern I have is if you go too far ventral, then you can get the motor nerve root instead of getting the medial branch. Right. So in either of those positions, as long as you don't go past that ventral border of the superior articular process, you should be safe because that relationship stays stable despite the spondylolisthesis. That's fair. Thanks. Just one last question about LSTVs. LSTVs are asymptomatic a lot. As you said, the prevalence is 4% to 30%, and we see it commonly in our back pain practice. How would you—and another point which you made was great. There's a supraadjacent level hypermobility or segmental mobility which happens. So let's say you have this patient of yours who came in and presented with back pain. How would you clinically conclusively say whether it is the LSTV pain or whether it's the supraadjacent segmental pain? Is there any other way of doing it? Like you could do it diagnostically by giving a diagnostic block, but is there anything clinically you would do that will help you ascertain whether it is this versus that? I mean, I think that's a great question. My personal alliance is still with the algorithm that I showed, which is that if the patient is really failing conservative care, then I probably would move to a diagnostic block just to rule the pseudo joint in or out because it could be the discogenic pain, it could be facet pain at the level above or whatnot. I do think this is where injections can be helpful. Would you prefer doing the LSTV joint injection versus the facet joint, which is supraadjacent as a first measure? That's a really good question. I guess if I see especially edema around the pseudo joint on an MRI, I tend to go for the pseudo joint myself. I wonder what the other people on this panel would do. We are not getting facet injections covered. I mean, I guess I can see medial branch blocks being an easy thing to do without even steroids for diagnostic purposes, but I kind of go based on the symptoms and also what I'm seeing on the MRI, and especially if there's edema around the pseudo joint. I agree with that, and we'll just add that if it's a type 4 where one side is fused, then I'm thinking the pseudo joint is less likely to be an issue, and I'm more looking at the supraadjacent segment. And then I'm old still, so I believe in physical exam more than I should probably, but I still like to do a PA compression test, and so I'll push one segment at a time, and if that sometimes can help me fine-tune where somebody says, yes, that spot hurts but that one doesn't, then that will help lead me in one direction versus the other. So that's all I have to add. This nice lady right over here is trying to kick us out. I heard. Okay. Thank you all for coming. Have a great day. Thank you.

anatomy

lumbar joints

pseudo-joints

pain differentiation

facet-mediated pain

headaches

low back pain

radiofrequency ablations

embryology

suboccipital joints

cervicogenic headaches

lumbosacral transitional vertebrae