Surgical Treatment Options for Degenerative Spondylolisthesis

Speaker 1Terrific. Thank you, Paul and, and thanks to everybody who, who's logging in. I think the topic we're gonna address today, uh, macular degenerative spondylosthesis is something that's such a common disorder and, uh, I think, uh, all of us who deal with the adult Spine problems certainly see this quite regularly.

Speaker 1This idea of the spar discussion is really to try and talk about the spectrum of approaches and to some extent the advantages, disadvantages of approaches under different circumstances and the purpose then being to try and and come up with the appropriate treatment for the appropriate patient. So by way of an overview, we'll start off just with the observation that how we manage degenerative Spondylolisthesis is really characterized by significant variability.

Speaker 1Uh, Options may include, uh, decompression only, uh, decompression with the limited fusion, and, and, and perhaps decompression with a circumferential or posterlateral, uh, uh, uh, fusion. And, and then finally, uh, maybe recognizing in some cases deformity comes into this as well. And when do we need to really reduce the deformity.

Speaker 1Well I'll go ahead, next slide. So, so this is a Pathology that we're uh really addressing today is degenerative spondylisthesis characteristically at L4-5 with an intact posterior arch to the Spine and ollisthesis or forward slippage of L4 on L5.

Speaker 1in this instance. Sometimes this may be associated with a component of rotatorory subluxation as well. But, but characteristically, uh, this causes, uh, central stenosis, uh, at L4-5, as well as lateral recess and sometimes foraminal narrowing. Well, if you go to the next slide on the MRI scan, again, characteristically, what we tend to see is narrowing of the neural frame and in this case, the exiting, uh, framing here for, for L4.

Speaker 1Uh, oftentimes we may see some, uh, gapping of the facet joint. Uh, this is really an indication of significant mobility of that olisthesis when we see, uh, a fluid in that gap because with the patient's supine posture, uh, there's a translation that may, may reduce partially supine compared to when the patient's standing.

Speaker 1And then oftentimes characteristically some significant central stenosis as well.

Speaker 2So in, in that particular case, a patient presents to you like this, do you typically get dynamic films?

Speaker 1Yeah, Paul, my, my, my preference here, uh, in, in terms of films, my preference to get, uh, standing films initially. Uh, if the patient's got a known diagnosis, then, then, uh, yes, I do prefer to get, uh, dynamic films and see how much mobility there is. And, and you'll see in, in the, uh, small classification I'll present that it makes a difference to me whether somebody moves less than 3.

Speaker 1Millimeters, 3 to 5 millimeters or somebody who really moves more dramatically. So I prefer to get flexion extension views. I think that sometimes the supine versus standing can be a substitute or an opportunistic way to take a look at rough mobility, but flexion extension I do prefer.

Speaker 3I'd just like to say that uh I get flexion extension films on anybody I'm considering operating on because I want to know if I have mobility or not. I think your flexion films have to be seated flexion. That's the only way to get true lumbar flexion. If you do standing flexion, you get Hip flexion, not lumbar flexion, especially in a patient who's spasmed, so.

Speaker 3Um, you know, I've had patients who I didn't think were slipped that moved quite a bit on inflection film, and that may change my management. So, that's one of the reasons I, I like the flexion extension film on people who are operative candidates.

Speaker 2You know, I think that's an excellent point, Ray. You know, every single time I listen to you talk, I learned something, and the idea of getting the, the seated flexion X-rays that that makes an awful lot of sense. So that's a great point. In this particular case, um, if the patient presents to you with purely back Pain or just, uh, bilateral claudication or unilateral radiculopathy, you're gonna treat the patient differently?

Speaker 1Yeah, but Paul, let, let, let's go, let's go forward, uh, uh, one, and I think I'm gonna address that, uh, uh, soon, uh, because I think a lot of variation in how we might address this and in terms of our options is, is when might we just decompress. And I think that there are circumstances where we, we decompress alone, uh, either with a minimally invasive technique or an open technique. I think, uh, you know, when we think about decompression alone, uh, the work of, of Heerkowitz from years ago.

Speaker 1Uh, would suggest that maybe we want to do some sparing of the posterior elements, uh, so some degree of a, of a less invasive Surgery to prevent destabilization. But at the same time, uh, decompression alone, a decompression with just a posterior fusion or, or a circumferential fusion, and, and then finally, perhaps some, some motion preservation options. And I think each of these may be appropriate under different circumstances. So, so if we go to the next slide, there's a uh

Speaker 1Uh, again, a lot of variability in how we might, uh, address the individual case and applying the, the right technique according to, uh, certainly, uh, the patient preferences, number one here, what are the goals of uh patient? What is the patient's presenting symptoms? So applying the right technique to the right proce uh, patient, uh, by the right person. Um, so some of the specific things that I think about in trying to apply the

Speaker 1Appropriate technique. I, I looked specifically at, at the alignment, uh, but both the, the segmental alignment, uh, so sometimes we may see significant kyphosis between L4 and L5, as well as the, the, the regional alignment is, is do I need to really try and get some restoration of alignment, uh, from L4 to S1. And then I look more specifically at the patterns of stenosis. So it is the stenosis in the foramen primarily as we see in the lower right-hand corner.

Speaker 1Is it in the, the lateral recess, or is this a stenosis where we're overgrown facet joints and that superior articular facet is really encroaching on a lateral recess, or is this more of a central pattern of stenosis?

Speaker 1And then, then finally I look at the stability of the Spine. So, are there bridging osteophytes, and how much motion, how unstable is this flexion extension? So I might pause there and say that these are really the things that I look at in terms of what are my specific goals for where I need to decompress, what I need to do for realignment, and how much I need to think about stabilizing the Spine.

Speaker 2I particularly like this image here right here at the bottom because it really shows the foramen, the foramen, and, and the Pathology that we commonly deal with in my practice. I see a lot of elderly patients that have a unilateral radiculopathy and foraminal stenosis, and that's sometimes somebody that I don't necessarily want to go in and do a big procedure. Uh, Dr. Gardai and I do a fair amount of, uh, transaminal endoscopic work, and this just shows that the pertrophy ligament, the sort of pseudo disc out in the frame and really crowding this, and.

Speaker 2And Ray, maybe you can describe, you know, sort of what some of the goals that we have when we do endoscopic Surgery, how we decompress this foramen.

Speaker 3Yeah, so, basically, with the endoscope, you can raise the roof and lower the floor, so you can remove the pseudoherniation and you can remove osteophytes off the back of the end plate and remove that ligament, the ligamentum flam, and tip of the supraticular process.

Speaker 3Um

Speaker 3And expand the foramen both fore and aft and top and bottom, um, you know, if you really have pedicle on pedicle stenosis, the best way to address that is still going to be an innerbody fusion because you're gonna stick something in the disc space and spread the pedicles out, and that's going to sort of address most of those things, so.

Speaker 3You know, when we discuss things like indirect decompression, I think it's highly effective for foraminal stenosis. Um, you know, it's, the issue with lateral recess stenosis is sometimes the stenosis is within the same vertebra, the supraticular process, and the disc space in the back of the body of L5, for instance, at L4-5 can, can be the place where the nerve is compressed, and that's where direct decompression is at least more appealing, appealing to me intellectually.

Speaker 3And, uh, you know, especially in the setting of, uh, say, a spodi where you do a flexion extension X-ray and it just doesn't move at all, I'm much more likely to do a less invasive decompression, even more so now that I can do this endoscopically because, you know, I submitted some, some papers for references and Doctor Hartle has a great paper about doing uh limited, limited, uh, minimally invasive decompressions for patients with degenerative spondylosthesis and getting quite good results with little need for further Surgery.

Speaker 3So, you know, the, the less disruptive you are to the soft tissues, and the less likely you are to provoke progression of Spondylolisthesis, the better the chance you have of getting long-term results. That's one of the things if you go back and look at the original Heerkowitz, uh, uh cohort, and you look at the patients who did really well long-term, you know, the ones who had a decompression that didn't progress did fantastic.

Speaker 3So, you know, can we, are we smart enough to figure out who those people are before we operate on them, or do we have to wait 10 years after we operate on them and go, oh, that wasn't one of them. And I think that's kind of what this discussion, the, the, the, um, the impetus behind this discussion is.

Speaker 2Well, I think that's now a perfect segue into, you know, what are the specific goals. So, Sig.

Speaker 1Yeah, so I present this as a classification, and I want to credit one of our former fellows who's now an assistant professor at the Ohio State University, Paul Ekins here, and so he put together this, this framework as looking at three major components. So the structural stability of the segments, and he classifies structural stability.

Speaker 1is less than 3 millimeters of translation either on flexion extension or between supine and standing films, and again I do prefer the flexion extension where we can get it, then 3 to 5 millimeters being an intermediate zone and then more than 5 millimeters of translation being really quite mobile.

Speaker 1And then the next category was, was where the stenosis is, and as Ray just suggested, uh, recognizing when is the stenosis just in a lateral recess and just central, in which case perhaps the decompression may work well. When is it in the foramen, but not really up down, and that was again what Ray said when it's pedicle on pedicle, I think we

Speaker 1Really need to do something to restore that height between the pedicles. But, but if it's simply anterior posterior, then either with the endoscope or with the minimally invasive decompression, we may be able to get significant foraminal decompression as well. And then finally, when there's up down foraminal stenosis in my hands, that's when I'm going to really try and get some, some height back.

Speaker 1And then the third category was, what's the alignment. So if that segment between L4 and L5 is already lowerotic, I'm not terribly worried about restoring segmental alignment.

Speaker 1But when that becomes kyphotic or certainly when there's a global malalignment, that's when I'm really thinking about doing something more reconstructive. I think we've got a kyphotic segment between L4 and L5. I'm very reluctant to to fuse that in situ because once that's fused, that really becomes a fixed kyphotic deformity, and it doesn't take much to transition somebody from a degenerative Pathology to to a deformity.

Speaker 1So that, that classification is really meant to, to give some guidance to uh an evidence-based Approach to, to, uh, when I think about a decompression only. Certainly in a patient that's stable segmentally, who's got lateral recess or, or, or central stenosis only where it's not uh uh up down foraminal stenosis, who's well aligned.

Speaker 1And that's a patient I'm gonna think hard about, uh, just decompressing and not, and not doing a fusion or maybe uh uh doing something uh more minimally invasive, whereas somebody who's got gross mobility uh at the level of olisthesis, up down stenosis, and either segmental or global malalignment, I'm really thinking hard about doing a reconstructive procedure in those cases.

Speaker 1So, um, in terms of the spectrum of options and, uh, a, a circumferential fusion versus a posterolateral fusion, uh, you know, I do think that there's some, some good evidence to suggest that there is some, some advantage to circumferential fusion over a posterolateral. I think our fusion rates are better. I think we get better indirect decompression, whether we do the circumferential fusion as a front and back or as a T lift.

Speaker 1I think our ability to restore segmental lordosis is better with the circumferential fusion, really putting something in the innerbody space that goes back to the work of, of Cloward. And, and then, uh, finally getting deformity correction is, is, is a big part of, of what I tend to see is realigning the Spine. So if we go to the next slide, um, um, this is really what we want to avoid, I think, is recognizing the patient to.

Speaker 1In this instance, a patient who has an olisthesis, a grade 2 olisthesis between L4 and L5.

Speaker 1And was fused from L4 to S1 and unfortunately, 5-1 had already been collapsed with uh with loss of lardosis. And now by fusing 4 or 5 into that kyphotic posture, now you've got somebody who's really got a problem where, where we want 2/3 of our lordosis in the lumbar Spine or really 2/3 of our pelvic incidence. We want that to be from L4 to S1.

Speaker 1And in this instance, you've got somebody locked into a fixed alignment from L4 to S1, uh, where there's no lower doses there at all. And this, it is predictably is going to lead to adjacent segment problems. The sheer forces at L4-5 become high. And if you take a look here, this is an X-ray that was done shortly after this patient's Surgery and uh go ahead and take a look down the road, uh, the next film.

Speaker 1Shows when you take a long-standing film and, and mind you, the, the film there in the middle with the long-standing film was done a few years after that fusion from L4 to S1, uh, but you see the progressive loss of, of global malalignment now. And this is just an example where I think, uh, uh, inappropriately or, or not recognizing segmental loosis.

Speaker 1Even in degenerative Pathology can, can lead to uh uh to more, more global malalignment. This is a patient who, who I saw at this time uh with, with uh stenosis as well as uh degeneration at the 3-4 segment, uh, just a couple, uh, just less than 2 years after a 4 to 1 fusion in malalignment.

Speaker 1And that's where I really think it's important. This exemplifies how important it is to recognize malalignment in our degenerative Pathology and certainly not fuse a degenerative olecystis in, in, in, in uh in kyphosis.

Speaker 3So

Speaker 3I say, here's a question for you, because I look at this and I think,

Speaker 3If we could see what the X-rays look like before the fusion, you had, you had some uh pre-op and measure the parameters, what parameter would we find or what combination of parameters would we find that warns us to say, hey,

Speaker 3You need to do a little bit more for this patient. This is not somebody that maybe this is, this really isn't the patient should be having a small Outpatient, minimally invasive procedure. They need a little bit bigger procedure that's really a deformity correction.

Speaker 1Yeah, great, great question, Ray. And, and, you know, I think it starts with, uh, uh, certainly preoperatively and not just with radiographic parameters, but, but taking a look at the patient, right? It is, uh, when we see a patient who stands, uh, with, with malalignment, who stands with a retroverted pelvis, that's a, a measurement I'm always gonna want to take a look at is a version of the pelvis. What I do is literally lay hands.

Speaker 1on the patient. I'll put my long finger in ASIS, my thumb on the PSIS, and get an idea of their pelvic version. Um, most of the time in my practice, I, I tend to get 36 inch standing films. Now, in part that has to do with the fact that I've got a, a, a largely deformity-oriented practice, but in part it's, it's got to do with the fact that, uh, I really do wanna try and, and get an idea of.

Speaker 1Of global alignment of the Spine. Uh, but even with a short film, you can look at the pelvic tilt, see the patient who's retroverted with regard to the pelvic tilt. Just look at the segmental alignment between L4 and L5. And the main thing I want to see is I want to get an idea of what the relationship is between the pelvic incidence and the lumbar lordosis.

Speaker 1And recognizing that 2/3 of my lordosis ought to be from L4 to S1. That's why in much of my practice, I'm driven towards uh doing something circumferentially to, to restore that lordosis from 4 to 1 because when we lose that, that's a strong predictor of adjacent level Pathology.

Speaker 2And so in this particular case, you know, the original surgeon, uh, performed an innerbo at L5-S1 but not at L4-5, um, and perhaps that would have been an opportunity to at least provide some correction to avoid this later on.

Speaker 2Do you think that some of the surgeons avoid doing innerbody fusion because uh of the complication rates associated with uh a circumferential fusion as opposed to just a poster a lateral one?

Speaker 1Yeah, maybe I'll start with that one, but Ray, I certainly like, like your opinion on it as well. Um, in terms of a, a circumferential fusion versus a posterolateral fusion, uh, even in the sports study suggested that there was a, a, a higher complication rate, whether we get our circumferential fusion, uh, with the TLIFF, uh, and we

Speaker 1Case, maybe we're taking a risk of a higher risk of a dural tear or a nerve injury, or with the front and back Surgery where suddenly we're introducing the risk of possible vascular injury or, or Other problems. Uh, uh, I think that uh that that the Approach related morbidity of this is important and

Speaker 1And to that end, uh, the, the right procedure in, in the right hands, I think is, is awfully important. Uh, you know, at L4, 5, I'm concerned about a direct lateral Approach, uh, perhaps, uh, uh, getting involved with the, the femoral plexus, uh, concerned about a TLlift, a possible nerve root injury, uh, an A lift, possible vascular injuries, and I think all of those considerations and that risk-benefit complication profile, uh, are, are, are things that, that everybody takes into account when they consider Approach. What, what do you think, Ray?

Speaker 3Also, uh, years ago, I kinda went to relying on the innerbody fusion and trying to avoid the posterolateral fusion just because when I looked at my own patients, I would see robust inner bodies and, uh, not so robust posterlaterals, and I, I didn't really feel like I had, uh, an innerbody pseudoarthrosis that was frequently rescued by a posterolateral fusion.

Speaker 3So, um, then I found myself asking people who were presenting a lot on T lifts, why they do the posterolateral fusion, and the number one answer I got was, I could bill for it. And, uh, I wasn't happy with that. So, one day I decided I'm gonna stop doing that. And, uh, strangely enough, patients started asking if they could go home from the hospital the same day or the next morning.

Speaker 3So, not disrupting the erectrospine and, and posterior musculature and having a deep dissection and working through a fixed tubular channel in the innerbody space, just didn't hurt as much. Uh, and I, I seem to get similar fusion rates. I relied on the innerbo space.

Speaker 3And, uh, that's what actually led, led me to converting these to Outpatient surgeries 12 years ago. So, um, you know, I, I, I sort of was ahead of eliminating the posterlateral fusion. Of course, when uh they started to bundle the posterlateral fusion, lots of Other people began to do that. So, um,

Speaker 3You know, I, I think, I think you can get your best correction, the best reduction, the best restoration of lordosis through the inner body space. I think if you're relying on posttralateral portion of it, it's not as good. And I wanna save that multifitous muscle cause it's a very unique stabilizer. It's the Primary stabilizer of the lumbar Spine. I wanna maintain the erector Spine as much as possible. And, you know, my general Approach.

Speaker 3So I would say that, uh, in, in general, patients with a degenerative spondylosthesis, they are deformity patients in that if you don't reduce the Spondylolisthesis and restore segmental lower doses, you can cause problems. But I don't know that they all need bilateral facetectomies, which I think is probably our main philosophical difference here. Um,

Speaker 2well, we just, we just received a really great question from Paul Eienserer. He says many surgeons fail to restore lower doses through a TLII Approach.

Speaker 2Could you guys comment on the technical pearls to avoid kyphosis with the TLLF in correcting the segmental deformity?

Speaker 1And maybe I'll start with that one, Ray. So, so Paul is uh the person I attributed the, uh, the classification to. Paul, Paul's uh, uh, assistant professor at the Ohio State University, one of our former fellows, and, and, uh,

Speaker 1What is, uh, leading you on to there a little bit is, is the observation that, uh, to really create lordosis, uh, is a challenge. Uh, uh, I, I think it's a challenge, uh, well, no matter what Approach you use, but I think with the TLLIF particularly, we, we all recognize some of the studies in TLIFs that suggest it's just as likely to be a kyphogenic, uh, procedure as it might be a, a lordogenic procedure.

Speaker 1And in the absence of really uh paying attention to facet joints and, you know, quite honestly, when I'm trying to create segmentalloidosis, truly doing a, a swab grade 2 osteotomy. So doing, doing truly a, a, a Ponti type osteotomy fulcruming over that anterior cage, that's how I get segmentalloidosis and uh I, I don't think I could do it reliably in the absence of a, of a pretty aggressive bilateral fastatectomy. But Ray Ray, what, what are your thoughts?

Speaker 3Well, I think it depends on the patient, right? So, that's part of the reason they get the flexion extension X-rays, because if you have people that uh reduce significantly either on the MRI supine imaging or when you flex and extend them, and they basically reduce, that shouldn't be very hard to achieve on the table, prone on the Jackson table with hips flexed. So, you know, if it's, uh, if

Speaker 3They're a grade 1 going on grade 2, and they sit and flex forward and they go to a grade 2 for going on grade 3, you're gonna have a hard time with that. And, and yeah, that's the patient you may need to do bilateral facetectomies. Now, you need to do that open? Can you do that through a tubular Approach? I think you can, I think you can still do that in a minimally invasive fashion, remove the bony structure and spare some of the musculature. Um.

Speaker 3You know, the older the patient, the harder it is to prevent subsiding because the bone quality is not as good. Uh, I think the, the major, um, changes coming down the pike are gonna be implants with larger footprints that give more of an A-lift size innerbody fit through a posterior or, or posterolateral Approach or the PLIF or T lift, um, because still, if you look at the, what, what surgeons do across the country, the majority are still doing posterior Surgery.

Speaker 3I think it's 20% are doing laterals and something similar, anteriors, and then, you know, you have the elderly patient with a calcified aorta. You don't wanna go in the front there. You don't wanna throw emboli. So, you know, there's a place for each of these, which is kind of why we didn't want to turn this into a, a all or nothing debate because it doesn't make sense to, to do it that way. But I would say that the majority of the patients, at least the ones that I see, um, and maybe they know I don't do deformity Surgery.

Speaker 3Um, would benefit from a, from a less invasive Approach because, you know, one of the things is, is when you look at these patients postoperatively, even if you don't get perfect segmental correction, you still get overall lumbar lordosis correction. So, uh, I have even decompression patients that have had improvement in lumbar loidosis just with the decompression. So, there's a component of the loidosis that you get, um, even if it's not 100% through the single segment.

Speaker 3And then there are patients who get good segmental correction, and they don't get great lordosis correction. So, um, it's not an all or none thing, and I don't know that we know who, who exactly needs what preoperatively. That's part of the problem. I think, I think some of the stuff that Sig presented, like if your SVA is off and you're standing with Hip flex, Hip flexion, yeah, you're gonna need something bigger. You shouldn't be coming to an Outpatient center to have Surgery.

Speaker 3Um, you need an open procedure and a, and a deformity correction. But at the same time, the average person with a grade one slip, claudatory leg Pain, some mechanical back Pain, they reduced pretty well on flexion extension.

Speaker 3I think you can minimize their morbidity, um, improve their recovery, minimize their narcotic use, and maintain their dynamic stabilizers, which I think is very important in preventing adjacent segment degeneration. And some of the papers that I submitted for the bibliography even goes into the fact that it looks like minimally invasive Surgery may have a lower adjacent segment degeneration rate than open Surgery.

Speaker 3So, um, matter of fact, Sig presented, uh, published a paper, um, about, he did a meta-analysis looking at lumbar fusions and how do you avoid adjacent segment degeneration. He said, fuse fewer segments. So he basically made the argument for a less invasive Surgery.

Speaker 1Yeah, I, I, I agree with you, Ray, and I think, you know, sparing the multifidus, as you indicated, that's, that's play a big part of adjacent level stability.

Speaker 2So why don't we, uh, move ahead, ahigg.

Speaker 1Yeah, go, go ahead to the next slide there, Paul. So that was just a slide to indicate that's what I want to avoid, um, uh, is, is, is, uh, fusing somebody in kyphosis, creating global kyphosis. This slide was really to, to focus on the framing again and the notion of, of, of decompressing the frame and so often, um, this stenosis can be an up-down stenosis or it can be a, a, a front and back stenosis. When you've got somebody who's got a, a very coll.

Speaker 1disc space like this, I think the opportunity to really open that disc space, this is to me a real invitation to try and do something in the innerbody space and eliminate some of that up-down stenosis, uh, uh, with an innerbody fusion. So paying attention to the foraminal volume, which I think I could open up much more effectively, uh, with an innerbody graft. I also worry a little bit if I, if I don't get some hype back in this innerbody segment, and I try and create

Speaker 1Loorosis. I'm very concerned without a big facetectomy here. I'm very concerned about pushing that superior articular facet further into that nerve root. So one of the major concerns, I think that can cause postoperative radiculopathy is an inadequate facet resection and then trying to compress across the posterior elements and recognizing that is, is, is another reason I tend to do a rather generous resection of the facet joints.

Speaker 2And one of the questions is going to be about decompression only without fusion. We'll get to that in a later slide.

Speaker 1Yeah, so I pay a lot of attention to the foraminal uh area where the foramen is tight. Again, this is a, a close-up of the picture you showed earlier, Paul, but, uh, ventral and, and dorsal stenosis, um, where the transaminal Approach, uh, really, really taking out some of that, uh, uh, dorsal as well as ventral mass to be very effective. Here's a patient who's got not much.

Speaker 1Up-down stenosis, uh, but ventral and dorsal stenosis might be a bit of an invitation for, for, uh, you or, or, or Ray with an endoscope to, to decompress that. In my hands, generally, that's gonna get taken care of, uh, uh, with, with, with an, an open procedure in a, in a, in a, a wider resection, both of the disc in the front and the, the, the facet in the back.

Speaker 1So this was, uh, uh, uh, I'm gonna wrap up here, my, my section with a, a case that I think would be a, a, a reasonable argument for doing a circumferential fusion. And, and we're, we're gonna show a spectrum of cases here and a spectrum of approaches. But I'll, I'll just introduce this one. This is a 68 year old woman.

Speaker 1And uh her um presentation is that she's got a degenerative olethesis at, at 45, but she's also got a significant isthmic olethesis at 51. The reason I, I chose this case and, and perhaps it's a little bit more extreme, but I wanted to point out that on a standing film, what we can see here is that uh we can see the lordosis from L4.

Speaker 1To S1 is is truly uh compromised. So this, I think I, I've got the measurements in the next film if you want to, Paul. Uh, maybe one more click. This is, this is actually the, uh, the MRI scan here. So again, there's an isthmmicolisthesis at 51 with the, the degenerative olisthesis actually reduces quite, quite impressively here on the supine image.

Speaker 1If you click one more forward there, pull one more, there's gonna be the uh the measurement. Oh, go ahead, go ahead back one, I'm sorry.

Speaker 1I thought I had, I thought I had the measurements on here, but basically what I, what I wanted to show here was, uh, this is a patient who's got a relatively high pelvic incidence. Her pelvic incidence was about 68 degrees.

Speaker 1And if you look at the lardosis from 4 to 1, just on a standing film, anytime you see L4 being kyphotic relative to the horizontal, that's even on a short film, that's what gives me a little bit of of concern about a lumbar pelvic mismatch. And this is somebody who I think it would be very easy to lock this patient from 4 to 1, to lock them into a relatively kyphotic.

Speaker 1Posture and I think that we know that the natural history of the adjacent segment there if we lock this kyphotic posture in place is that that adjacent segment would be subject to significant sheer forces and would wear out quite quickly and one of the references I had submitted was a paper out of Switzerland by Kaim Min Min who wrote about.

Speaker 175% rate rate of adjacent level degeneration when we don't adequately restore lower doses from L4 to S1. So this is one maybe we could talk about a little bit, but, but I, I chose to go circumferentially. Maybe I'll show what I did and we can uh uh talk about it. I, I chose to go circumferentially. Sometimes, uh, I, I'll do a, a posterior-based, uh, decompression and a, and a realignment.

Speaker 1Type of a procedure. I think we uh um click through this a little bit. This is a, uh, uh, uh, uh, uh, an example where uh using um my, my, uh, osteotome, sometimes I'll, uh, shave off some of the dome of S1. I'll tend to use a paddle between L5 and S1. This is actually a dysplastic olisthesis case, but I put it in here as an example. Go to the next slide, Paul.

Speaker 1Is, is that's the end. Oh, that, OK, um, uh, in that case, uh, can you run? Does the video run or no? OK, so I'll use a paddle and I'll, I'll actually, uh, uh, mobilize L5 compared to S1 and using a posterior based technique, really, uh, get a good restoration, uh, between, uh, in this case, the, the L4 and S1, getting segmental loosis with a, a pretty aggressive mobilization of the, of the, uh, disc space on both sides. I think.

Speaker 1Uh, do I have the post op in there, Paul, or did that get cut out?

Speaker 2No, it's not in here. Uh, no, it's not in here for some reason.

Speaker 1But again, I show this as an example of a case where, where my preference is to be quite, uh, quite aggressive about the discectomy, get my cages up towards the front of the innerbo space, fulcrum over the cages, and get a lordosis from L4 to S1. And that's something I, I really do need to do uh with an open Approach and, and a complete facetectomies in order to avoid a postoperative uh kyphotic alignment.

Speaker 2OK.

Speaker 3Well, so I like, I, I don't think there's anybody that's gonna mistake this for one that should be done with decompression alone. So I think we can say that.

Speaker 3Um, and really, two-level spawning, you got an isthmic and a degenerative adjacent, that's a deformity. I mean, that's even, uh, one of the things that I, I noticed on that pre-op film, that patient had a very high pelvic incidence and a very steep sacral slope, yet had a good, uh, had a significant, uh, PILL mismatch. So that, those are the patients that, that worry me the most because, you know, on the overall standing film, they don't look terrible. Um, but

Speaker 3Their lumbar lordosis doesn't match their pelvic morphology. And, you know, those are the patients, like I see that sometimes, um, in patients with a large uh PI, large pelvic incidence, and, and pretty steep slope, and they kind of have that junk in the trunk body habitus, right? They're kind of, kind of pitched forward, but they've got pretty good lordosis. The lordosis isn't necessarily far off the pelvic incidence. Those are the patients that make me nervous because

Speaker 3Unless you recreate a lot of segmental loidosis there, they just, they're already compensated as far as they can go. And, and maybe I'm, I may be missing some Hip flexion contractures in those patients, I think that's just the way some of these patients are shaped.

Speaker 1I agree with you, Ray Ray. I think recognizing that high pelvic incidence morphology makes a difference to when I go front and back versus posterior only, but

Speaker 1Recognizing that, uh, high pelvic incidence and, and again, we want to get 2/3 of our lordosis, uh, from L4 to S1. Sometimes, you know, we, we might want 40 degrees or more uh of lordosis between L4 and S1. So I think that, that's awfully important and can be very challenging to do, uh, a posterior only sometimes.

Speaker 2Excellent. So we're getting along long here in time. I know so you have to, you have something you gotta do. Why don't we go ahead and move into the case presentations by Doctor Gardai. We have, uh, several, uh, cases.