Baptist Health Miami Neuroscience Institute invites Dr. Edward C. Benzel to discuss advancements and best practices in spinal surgery and neurosurgical biomechanics.
Welcome everybody. This is the first invited lectureship of 24. Um, thank you to the spine surgeons. The physiatry people, the neurology faculty who came. Um, and, uh, today, I'm gonna ask Doctor Vitale Sielman to introduce Doctor Benzel because Doctor Benzel was one of Witt's professors when he trained at Cleveland Clinic. Wit. Good afternoon. Uh, it's not just one of the professors, it's the professor, and, uh, I'll just go over the formal introduction and the, uh, it's it's, it's, it's an honor and a privilege, Doctor Benzil, uh, and, uh. Back in the day, it was just a lot of fun to to be with you in the operating room. It's uh it always whenever we would scrub, Doctor Bezo will take you through the case with enthusiasm. It was always a great educational opportunity, uh and uh it it was just not only educ education was always a lot of fun and uh and uh a lot of uh information, a lot of knowledge, it's just a walking encyclopedia of everything. Um, so Doctor Benzo was born in Spokane, Washington. He received his chemical engineering degree from Washington State University, and then his MD from Medical College of Wisconsin in 1975. He then continued his training in neurosurgery, and then neurosurgical fellowship in Wisconsin, completing studies in 1981. Then he became chief of neurosurgery at Louisiana State University, uh, before moving to the University of New Mexico, where he was chief of neurosurgery from uh 89 to 99. During this time frame, he established a neurosurgery residency training program and a spine fellowship. He then moved to Cleveland Clinic to become the director of spinal disorders and uh has continued his career there since. He has been chairman of the Department of Neurosurgery until 2017. He is known amongst his neurosurgical colleagues as the engineer among spinal deformity neurosurgeons. He has a very conservative and pragmatic approach to neurosurgery for disorders of the spinal column. He has given more than 200 invited lectures, authored and edited 35 books, authored 3676 book chapters, and 254 peer-reviewed papers and 328 abstracts. And as an educator, he has been honored with 6 teaching awards. Uh, the list of honors for the spinal neurosurgical career are lengthy, but include the Pioneer of Spine Surgery award at the North American Spine Society, uh, the World Federation of Neurosurgeons, uh, William Beecher's Scoville Prize in 2011. The outstanding contributors to a Medical Science worldwide award and the Brazilian Congress of Spine Surgery in 2013. He was the honored guest of the Congress of Neurological Surgeons in 2014, and he made a special private presentation to President George W. Bush on spinal sensor technology. In 2007, he was he has educated over 100 residents and fellows, held 18 grants and 11 medical, uh medical uh patents. His service uh for uh uh organized neurosurgery spans 4 pages on his 159-page curriculum vitae. I, I'm, I'm done reading. It's very impressive. All right, so, uh, we'll all welcome Doctor Benzel. Actually. I am truly humbled by your comments. Um, it's always been a favorite. Um, residency is tough, and he went through it like, uh, nobody's business. And I've heard from so many, so many people here, how well you are doing it like I told Doctor McDermott, it just gives me goosebumps. Thank you. So, I was asked to talk about something, and I said, you know, how about cervical myelopathy and cervical spondylosis. And then um I said to Mike last night, I said I could throw in a little biomechanics and he says, oh no. And so I said, how about, uh, this is actually not in the same order, but how about uh talk about talking about artificial discs, and so I'm going to do that a little bit after I finish with the talk on spinal uh on cervical spinalosis. A cervical spinnaloic myelopathy is a manifestation of encroachment and tethering and repetitive trauma. So the spinal cord is stretched, pounded on, etc. repetitively, causing it to gradually deteriorate. Um. OK. These are all patients with a cervical spinalosis. Anybody have any guesses as to what the two major complaints for every single one of these patients is? Neck pain? And I'll tell you the next one in a second. Let's start with neck pain. The patient's spine is bent forward, the spinal cord is usually being uh compressed. And we see this kyphosis trapezius sign. This is where the patient uh is trying to correct the deformity. Uh, but cannot and cannot get it done with the normal spina muscles, and so, uh, the, uh, Trapezius muscles are reflexively activated. OK, they're not positioned well to accomplish the task, and henceforth the patient ends up with a myofascial pain syndrome. The second one is back pain. Why do they have back pain? Well, this patient, for some reason that I'm not entirely sure of, had this occipi to thoracic fusion. And unfortunately, it uh it took, um, and this is what she stuck with. She was fused looking downward, OK? So what does she have to do if you look at this. X-ray, you see that the plumb line, which should be falling in line with the vertebral bodies is falling way behind the vertebral bodies. So the patient is stressing the spine in extension, and almost all these patients will have back pain associated with their neck pain. This is even a better example. You can see the kyphosis here. And the extended spine here and the trapezius sign kyphosis trapezius sign here. So, a lot of these patients are in firm, um, not healthy, frail, um, and so we need to try non-operative strategies if possible. Obviously, postural strategies will work, uh, potentially, uh, causing the patient's neck to extend. Um, keep in mind that this patient with ankylosing spinylitis on the right side, uh, spent a lot of his time in bed on his back with a pillow because it felt better to have his head flexed with the pillow, and this is his punishment. Now we have biologics and understand this process better, but in the day, uh there were a lot of these people running around. So we can also work with a variety of strengthening exercises, and although I have never seen a patient uh images improve or the angles improve, I've had a number of patients improve clinically with regard to those two strategies of uh strengthening and stretching. So, there are a number of surgical strategies. We know that if we can keep the spine straightened and extended in normal lower doses, the patients have a lot better uh outcome from a quality of life perspective. Um, I'm gonna show you a grave mistake I made, and I show this a lot to continuously remind myself and burn her images into my heart, because I did this lady no favor. Uh, here she is, she has a cervical myelopathy, um. And this is her post-op x-ray. So what's wrong with the post-op x-ray? She's her spine is straightened. I didn't this, I did this case years and years ago, and I didn't really appreciate this as much, um, but this is one of the earlier, not the earliest steps on the journey that I'm gonna speak about today. Um, and so when we do fuse, we need to make sure we fuse them in the proper position with normal alignment. There are a variety of strategies to try to deal with this. Uh, one of them is to just simply, um, loosen up the Mayfield tongs, uh, Mayfield head holder, and then straighten out the spine, we hook it up again, come back later, and extend it some more, we hook it up again, but it's very difficult to do that. Um, and when I keep coming back, say several times, uh, What am I, what principle am I taking advantage of? That that principle is viscoelasticity. The change in in in uh the shape of a body, uh at the uh because of the uh presentation of a constant load. So we can use tables that have tongs like this Gardner Wells tong right here, hooked into the patient, um, and can pull upwards constantly. I've only done this a couple of times and it scared me to death. Because if these tongues rip out, and I think we all of us have used them, know that they can rip out, um, there's not uh uh uh a lot of lot of keeping the patient from being injured. You can see we have this little fail-safe here, um, but that's sort of feeble. There's another shot. So, bottom line is, when we are treating cervical spinellotic myelopathy, we need to focus on deformity. Why? We can manage neck pain, we can treat myelopathy, we can decrease infusion degenerative changes, and more on that later. We can improve short and long term success. Um, intraoperative, uh, uh, deformity correction can be done ventrally and dorsally, and I've already made the statement that it's easier to do from a ventral approach than from a dorsal approach. But regardless of the strategies used, it's all about leverage. Here's some of the ventral techniques we can use Caspar pins to uh straighten or extend the spine. Um, we can use an intermediate point of fixation to bring the bone to the implant, that's further extending the spine. Here's an example of that. And so we convert a kyphosis or a kyphosis to a lower doses, and here we see that, uh, and we can use gravity and the viscoelasticity principle rises here again, a gradual deformation in response to a constant load. So, this is a patient I took care of around the turn of the century, um. It's sad to say I've been around that long. Um, but, um, she had had multiple operations. Um, she's 68 years old. Uh, I don't know if she had the kyphosis trapezius sign because I wasn't looking for it then. Um, so this is a journey that I took, um, but I did, did know that she needed to be straightened out. So this is her, her MRI. Um, again, there's some things that I just didn't dawn on me at this time with this particular patient, but she had these signal changes in her spinal cord. But what's unique about this position, or about this image is that she has ventral and dorsal patent subarachnoid space. So why would she have an injury to her spinal cord there? Um, Uh, I knew I could correct her ventrally because her facets weren't ankylos, and I apologize for some of these images, but they're old, uh, and notice how she opened up below the level of fusion, and I fused her in this position. Um, but I used this, I used all these techniques. I have a donut under her head, um, and I'm doing the relaxing procedures, the discectomies, etc. And then using caspar pins to put in maybe one or two of the of the uh struts, and then I take this uh donut from beneath her head and let her head go backwards. The head weighs about 10 pounds, and you can apply a constant load by just letting it at first it was suspended. It was not ask the anesthesiologist, is the head on the table? No. 20 minutes later, is it on the table? Yes. So gradually correct the deformity. Correcting cervical deformities, in my opinion, often requires a lot of patience on the part of the surgeon. And here we are doing these things, and here's your correction from a 15 degrees kyphosis to a 5 degree uh lordosis. Now, is this ideal? No, but getting more may have been too costly, and she did exceedingly well. She began improving with regard to her myelopathy, and you say why she didn't really have any compression. Um. Um, and, uh, I, I could have done her all prone and adjusted the head holder, but I would have to, um, be very careful. regardless, fixation follows, and here she is, uh, after that operation. And again, I could have done rather than multiple level discectomies, I could have done multiple level corpectomies and a posterior fusion, cause you need those intermediate points of fixation and I'll go over that later. But um that's two operations. Remember these people aren't the healthiest people in the world. And so I brought the bone to the implant, etc. and here she is post-op. Don't count on intramedullary signal changes going away after you decompress them. But these went away. Now why in the world. I might ask myself 25 years ago, didn't did they go away and why were they there in the first place? I think the the reason for all this is going to become abundantly clear here if you already haven't figured it out. Shortly thereafter, this also 68 year old male from Puerto Rico came to see me. 10 years prior, he had a cervical laminectomy. And now he's got a progressive myelopathy, um, and his MRI looks like this. So his surgeon sends him to me and says, you know, what's going on here? I got an MRI that looks good, um, and it's a little atrophy of the spinal cord, but it doesn't explain this progressive myelopathy. So, um, I know, I, I, I knew at that time that cervical spinlotic myelopathy was a manifestation of repetitive trauma and tethering and distraction. If I just go back a second, there doesn't appear to be any tethering or distraction here. But if I get a flexion X-ray, I see that there's a lot of motion. She, he can only extend to the extent that he can on the on the left image, and on the right image, he can flex quite a bit, which means all the facet joints are open, they're just sort of jammed by osteophytes. Um, so I got a flexion MRI scan. This is, I believe, the first dynamic um uh MRI of the cervical spine at the Cleveland Clinic. Um, I, there somebody else could have ordered one, but I, I, I don't know. So basically, he inflection is really traumatizing his spinal cord. Well, we knew. Uh, here's the neutral or extended one on the left and the flexed MRI on the right. So now this is becoming much more common, commonly used, and be careful because you don't want the patient to be in the MRI scanner and then go paralyzed because you have them in a compromised position. So the techs have to be instructed and and uh Familiar with the procedure. I knew I could correct him dorsally because all I had to do is unjam the facet joints, which means to do uh facet osteotomies at each level, um, which means basically staying dorsal to the nerve root and going all the way out, not 99% of the way out, but all the way out on both sides, um. And looking at preoperative imaging studies for evidence of an aberrant uh vertebral artery. Just have to make sure if we're going out into that territory that we've covered all bases. And so I did that, um, and you can see these facet osteotomies here. Unfortunately, my videos aren't working that I wanna show later. Um, At any rate, you can see the facet joints, and I don't know why my error, here we go. This is a facet osteotomy right here. It's all the way out. So here she is, we, uh, he is. We did him from C3 to T1 or 2, T2. Um, I, I made a mistake that I will not make again, is is that I went to C3 rather than taking it to T2. But again, it's been a long learning curve for me, um, because you lose very little motion and you gain a lot of traction. In other words, good fixation and you can hold the spine back. So here here's him slipping forward and his surgeon in Puerto Rico fixed him, just note that the C2 3 angle is not horizontal to the floor. This is an important parameter, at least in my hands. And so he fused him in this position, and he was very happy, even though he isn't, he's not uh anatomical, he's uh stable, and so uh things ended up good for him. OK, life goes on about 3 or 4 or 5 years later, I have this 32 year old gentleman. Who uh was involved in a motor vehicle accident and who developed a C-171 herniated disc. He was treated by a surgeon at, of course, Saint Elsewhere with this uh device that the surgeon took out and then he um he put it back together. He got it from the surgeon and put it back together. Unfortunately, when you want somebody to not fuse, they fuse. And so he fused in this position. He is not myelopathic, he simply got neck pain or the trapezius kyphosis sign. And you can see here is on the upper left is um he is not compressed, but you can see his neck muscles, the trapezius muscles are uh hypertrophied, and he's leaning backwards. He also has back pain. So here's a much better example of facet osteotomies. You can see how the facets have been drilled out all the way through, and so we drilled through the old fusions and the facet joints, and then flipped him over and did multiple level. Discectomies and instrumented fusion brought the bone to the implant. We used a viscoelasticity by the donut technique. And one other thing that I haven't mentioned, we use trapezoidal fibular allograft struts. So here he is pre-op, and around this time, operating on somebody for neck pain was sort of taboo, um, and still is. Probably appropriately so for the for the most part, but not every case. So sometimes it's more appropriate to correct at another level. This lady has neurofibromatosis, dural lactasia, um, and has had multiple uh upper cervical operations, and she's basically got an ear on shoulder deformity with the ectatic blood vessels, etc. Um, and here she is, pre-op. Um, so we took her to the operating room and fundamentally, what we were dealing with here, and I'd never tell an insurance carrier this was a cosmetic operation. Because she was miserable because she couldn't get a date and uh we fixed that. Um, so we got a position on the table. I started doing the ectomies, as you can see here. Um, Right, here is where the big one was, and then I went down, uh, Broke scrub went down and put her head in the position we wanted it in. And then um we finished the osteotomies, and when I got through the one that I just pointed at, There was a pop, crack, and a sudden movement. So, That's unnerving, um, and the patient has to be aware if you're gonna really fix this deformity that there could be a vertebral artery injury. So we were as ready as we could be for that, and fortunately, we didn't have it. And the, the X-ray report for this construct was pretty impressive. They, they couldn't understand where all these screws and everything were. But as a surgeon, we need to take advantage that's the of the anatomy that's given to us. Our job is not to make this look pretty, it's to be functional. And she was exceedingly happy after all of this. Here she is with a little thoracic scoliosis, which could have contributed to her upper cervical problems. Sometimes you don't want to do. The entire operation at the same setting. This is a patient with Progressive neck pain, uh, progressive myelopathy, and this finding on MRI. Here she is with CT and she, you can see that she's had multiple, multiple operations, um. And there was a very good reason we didn't want to operate on her from in front. Um, and so we said we need to do this from behind, and we took her to the operating room, did laminectomies and facetectomies, and said, I don't think we got any. I mean, I just don't know if we've gotten enough correction, and we couldn't see down below C2 because of her size, and this is in the day before uh alarm, and so we really had no imaging. And so we to close the wound, put her in the ICU, put her in gentle traction with a little roll under her shoulder. Got a CT scan, and we said, we'll take this. And so we put her in this position in surgery and did this operation. We took this, I believe, down to T3 or T4. She's got a heavier than normal head, um, and, uh, got, or maybe even further and got a great, uh, correction, um. These, these are movies that are not working, and I, I apologize for that, but here is that facetectomy I was talking about. Just got to make sure that the vertebral artery is not in an aberrant position. So She, she was a happy camper. She actually lost some weight for a while and then gained it back. So let's talk about the C2 3 angle. Something else we've learned along along the path. Um. If we, uh, this is a paper we published in 2018. If we, uh, look at an angle that's steep, in other words, the C2 3 angle should be horizontal and the standing position should be horizontal to the floor in a in a normal person. If it's tilted like this, um, then we end up with a statistically higher reoperation rate, pseudo arthrosis rate, progressive kyphosis rate, and adjacent segment disease and degeneration rate. It wasn't even close. So working on that C23 angle is exceedingly important. The other angle is the is the shape of the tt CT C7 T1 slope or T1 slope, um. It tells us something different. The 23, 2-3 angle tells us in the operating room whether we've got enough correction. The C7T1 angle that we see here tells us whether how how far down we need to go on a thoracic spine, and how much of a correction do we need at the cervical thoracic junction. Because this, look at this, look at her, she's, this patient has a basically an upper cervical ornosis, but yet has a horrible SPA, um, uh, sagittal vertical axis. In other words, sagittal vertical axis is if you take a They they line straight down at C2 and at C7 or T1. It's the different, how far it measures how far the patient is leaning forward. So the C2 3 angle has intraoperative utility. So this is a person who we would theoretically want to get into this position, but we, this is the same patient I had before, um, and we know that if we correct the cervical thoracic deformity, um, we can correct this angle at the same time. So here's a patient. I've already mentioned to some of you how I just love operating on redos, but this is a patient who's had lumbar surgery and multiple cervical operations, uh, and is miserable with the kyphosis trapezius sign and uh and uh and back pain. But the back pain, she comes naturally here with her old lumbar fusion. So what do we see that's wrong here? Um, well, she's leaning forward and so we're going to correct her deformity and do thet osteotomies and extend her. And so we use the C2 3 angle to determine when we've got enough correction. So you take if you take the picture on the left. And then just simply turn it 90 degrees to the left, and you can see what she would look like if she were standing. And so the C23 angle is pretty good. It's pretty close to being horizontal with the floor, and so we'll take that. So we're done with that. And here she is, um, after the surgery. And so, I, another thing that I think is really important for the spine surgeons here. Is getting scoliosis X-rays when you don't think you might not necessarily need them, and I'll show you a couple examples why I think that's the case. We need to know how patients are stacked up, um, because, make no mistake, the cervical spine affects the thoracic and lumbar spine, and vice versa. At any rate, here are her angles, her plumb line. It passes right where it's supposed to. Uh, from, from T1 down through the lomosacal junction, but this is pre-op, um, but her, uh, Her C23 angle is tilted. This is probably where most of her pain is generated from. Post-op, um, C2 3 angle horizontal to the floor. Right here. And the plumb line has now gone from a normal position to an admirable abnormal position. It's moved forward. Why didn't do that? This is probably her intrinsically normal posture at this with given everything that's going on, and with the film on the left, she was trying to, she's standing up, but she's supposed to be looking forward. So what's she doing, leaning backwards. It's a total pathological positioning of her, and so now she's more comfortable while having a less than optimal uh position of the plumb line. So I, I had had this patient, um, Who was a 34 year old male with a small fiber neuropathy, and he was miserable. a little bit of a chronic pain, but for the most part, uh, seemed like a relative straight shooter, um, and I had multiple partners tell me that you cannot fix this by just fusing the upper cervical spine. And I said, let me give it a try. So here is his spine, um, and this is sort of a neuropathic uh degeneration and deformation of his spine, um, and here is him laying comfortably on a, on a, on an MRI table, so he's got a little compression, so we wanted to decompress him down lower, um, and this is his, uh, scoliosis view. So this deformity in the cervical spine affects all levels, including the lumbar spine. So we did a C4, an upper C5 laminectomy, C4-5 bilateral frameinotomies, and the C2 to 5 instrumented fusion. We did not take it to the thoracic spine, which my partners would have, and I'm glad to say they were wrong. So here he is, and why did I know I could do this? Because he's young. We hardly ever operate on a young spine that's mobile. We're operating on a 70 year old or an 80-year-old whose spine is rigid, and you could never get this kind of correction from this approach in that patient. But in this patient, we did. And he was one of the most grateful patients I have taken care of. So here's his neck. Now here's his uh the scoliosis view. Um, and again, I'm a big fan of scoliosis views. You can see how his thoracic hump is diminished. He is much more, um, uh, his plumb line is lined up. He is, uh, there's a good reason for him to be uh happy with his surgery. So, um, We need to um put patient spines in the right posture. Um, and this is a list of old literature, there's more coming out, um, looking at um the effects of an abnormal posture of a disc inner space, like in kyphosis, and, and how it affects adversely adjacent segments. Um, and so there's a lot of stress placed on adjacent levels by abnormal and anatomically placed, um, spines. So, uh, remember, uh, with the C23 angle, uh, watch for we have decreased reoperation rates if we correct it, decrease pseudo arthrosis rates, progressive prevent pervasive kyphosis, we see adjacent segment degeneration and disease. And so there's these two patients both had an ACDF. And the patient on the left presented later with adjacent segment disease. The patient on the right is not represented. So they both had a relief of their symp of their radicular symptoms, that there was a big difference in how their how their spine degenerates. So I'd like to take that as a segue and spend 10 minutes and leave 10 minutes for discussion um on total disc arthroplasty. Um, sort of a hot topic all over the country. When we talk about total total disc arthroplasty, we want to know what kind of stresses are going to be incurred by the arthroplasty and by the adjacent segments and the same segment. Uh, that the arthroplasty is placed in. On the left with a a Charite disc which is metal and poly, if we load the spine vertically, uh there is uh it's infinitely stiff. OK, that's not normal. On the other side of a coin, if we have a a disk as we see on the right side, which is a ball and socket joint, um, we have basically uh no resistance to flexion extension and lateral bending. So, mechanical neck pain. Or mechanical back pain is basically related to these graphs, and I won't go into them with great detail, but this is a stress strain curve. A to B is the neutral zone. It's very loose. I'm throwing in a little biomechanics, OK? Um, A to B is a little loose, uh, and that's the neutral zone, and so I apply very little force and get significant movement. OK. Once I get to this point though, I have to apply much greater force to get a get movement and the that line from B to C is uh called the uh the elastic zone. And then if I keep pushing it, this will eventually fail. So if we're gonna talk about mechanical back pain, um, mechanical back pain is deep and agonizing pain that is worsened with activity and improved with with unloading. Um, this is it, the red curve. The neutral zone is widened, the spine is more sloppy, and so therefore, the patient needs to uh uh exert uh reflexively exert other forces to try to prevent that which induce pain. So let's look at variety of artificial or disc spinal implants and talk about flexion and extension, uh, and how, how they affect it. I already talked about the Charite really having a wide neutralsome because there is no uh resistance to flexion extension lateral bending, and this, uh, the second disc is a Acroflex disc is made by Steffi and Accramed Company. Um, and it was one of the first of the polymeric discs. It failed because the polymer, uh, it was actually rubber, separated from the metal, and you might see some sort of a combined or a hybrid curve. Most of you or a lot of you may be familiar with the Denis system, which is the third one, which basically stiffened the spine. You would think it could move the curve from the dotted line to the red line. And it probably does, but there's been no real good clinical evidence that it's effective. And finally, if you fuse the patient, you have a straight up curve, which is infinite stiffness. Now if we're talking about axial loading, the Chate disk loads significantly accepts loads significantly and axial loading and transmits those loads to above and below. Um, the, the Acroflex disk does the same thing, uh, no, no real comment about the last two. So, uh, I just mentioned this, adjacent segments versus same same segment stresses from from an arthroplasty, uh, both are significant, um, and we really haven't adequately, um, measured these and assessed these, um, but I'd like to, so a lot of the data from uh from artificial discs is recent, by that I mean under 10 years or so, um. Um, but the data that we should have been looking at, uh, to, to determine, I, I obviously have a bias here, um, and it's food for thought, and I don't know what operation is best in ACDF or an artificial disc, um, but, uh, I think we need better studies to prove that, to show that. At any rate, we look at Asian Jason segment degeneration, which is degenerative changes on imaging. Or disease which is symptomatic degenerative changes uh with imaging. So I'd like to just take a whirlwind tour through old literature, and this is from um 2004 by Hildebrand from the group at uh at uh In Philadelphia, um, they did 3 studies with the average follow up of 4.5 years, where they looked at the prevalence of adjacent segment disease, uh, following anterior cervical operations, and the annual incidence was about 3% per year. Just remember that number. Um, Henderson at all from Minnesota in 1983, looked at laminal foramenotomies. Um, they did 846 of them, didn't follow them all for a long period of time, and the laminal fra anotomy, for those of you who do not know, do not know, is a simple way of decompressing a nerve root. Uh, without fusing or doing anything to the spine, other than taking a little bone away and gaining access to the lateral recesses where the where the stenosis is is occurring. So they had a prevalence of 9% in an annual incidence of adjacent segment disease in a patient they didn't fuse it should be the ultimate. Um, motion sparing operation was about the same as the ACTF. Lunsford from Pittsburgh. In 1980, looked at 253 patients with ACD with and without fusion. Um, they didn't notice any difference, and they again saw 2.5% or 3% per year. And then the group from Philadelphia again, interestingly looked at single level and multiple level uh ACDFs and fusions, and found out that um the multi-level ACDF had a lower incidence of adjacent segment disease than the single level. So That one's sort of difficult to to sort out, but I am guessing that what they did was they had 45 and 56 and 67, and if they took an adjacent if they took an adjacent segment with a multiple level operation, they were taking a vulnerable level out, and so that it couldn't degenerate. So, Here's where my gripe is with the studies. All studies uh for artificial discs are done by surgeons who do artificial disc operations. There's an intrinsic bias with that. There's an academic bias, vested interest, um, study design issues come into play, um, post-surgical decisions and whether to take a person back to surgery or not, um. And then something that is talked about, but I don't think addressed enough, is the winner loser bias. These studies were done when there was limited access to the artificial disc, and the only way a patient could get to it. would be to have a uh go into a study, and if they went into a study and they got all allocated to the fusion group, they were a loser, and if they were allocated to the artificial disc group, they were a winner. So again I go back to What I think causes adjacent accelerates the adjacent segment disease is uh Uh, deformity, segmental deformity, and we should focus, focus, focus on the management of segmental deformity. And remember this study with the C23 angle. If we don't have a normal uh alignment, we have greater operations, reoperations, greater pseudoarthrosis rate, um, uh, progressive kyphoses and adjacent segment degeneration and disease. I thank you very much. I really. Mm. Uh, some of Ed's redos with those giant deformities remind me of shunt operations I would take UCSF like the loser cases that were very conflict, but it's right, if you stay with it, you can usually and do the right thing, you can fix it. Um, Raul, do you have a question? I really enjoyed. Um, I think how do, um, how do you deal with the, uh, Patients that are poor host, a poor host, severely osteoporotic, or that are not suitable for, for in this, uh, you know, they have fusion operation. Yeah, I mean, like, like I said, um, I will go to these exercises and say, listen, you're not a candidate for surgery. It's just too much, um. And you know, you get some people begging you, uh, and, you know, it's one thing if a chronic pain patient is begging you to do surgery, and you know you're not going to. It's another, another thing. When somebody who you know, you could possibly help with surgery is begging for it, and you say no. Um, but I think we need to do with it what's in reason, and I, my answer to them is if you really, um, want to get relief, the safest and best way, in my opinion, is to be aggressive with those exercises. Again, I didn't see any changes in posture, but I did see changes in symptoms. I was gonna ask, um, one thing you talked about was dynamic MR and you showed the posture of the patient in the static position. With the scoliosis films, is there any information about the effect of some of these deformity operations on the dynamic posture of the spine or gait after surgery? I'm not sure. I'm not sure what you're getting at. You're, you're saying well you stand there for an X-ray. It's another thing to walk down the hall and sure, uh, I don't, I know of no studies I know of any, um. Um, there she goes, OK, there, there you go, that's gonna do it. You got some work to do, but it's gonna be really hard to get a dynamic study unless you're doing photography, like somebody is just walking along like while they're walking. Yeah, so they can, they can do that now with smartphones. I enjoyed your lecture. It was fascinating. Uh, particularly, I was interested in the, um, the case you showed of the cord signal changes with that cord compression, and I've seen a number of those, and I have not gotten flexion extension or dynamic MRI's. And, do they have progressive myelopathy? Not progressive myelopathy, but they have their myelopathic on exam, yeah, when I see them. So, you know, the question is, maybe if we did an MRI and extension or flexion and saw that there's tethering there, then, because we couldn't figure out like where, where is the damage. They never had uh any major uh trauma, and there was no cord compression, but they had myomalacia changes. Yeah, so. I, I think you're, you're good, you're, if you do dynamic studies, you're gonna identify some patients who may benefit from surgery, yeah. So that I didn't show, didn't uh um highlight on that film with the we got the flexion view later, um, but he had a straight line compression. Let me. Yeah, I think that was shown in your film. I'm getting there. There is. So This straight line here. Um, I don't know that anybody has shown me. What I think in old spine surgery lore was a post laminectomy membrane. And I think if there is such a thing, that's it. So when he bends his spinal cord, his spine forward, he pulls that membrane and drapes the cord over the ventral osteophytes. Yeah, that's very interesting. Yeah. Thank you. Mike Gomez, questions. Uh, we had a nice chat about, um, counseling patients. I can talk loud. He's got a big mouth. uh, we talked about counseling patients who, um, Had a severe cervical canal stenosis with cord signal change. Um, I, I use the example of a 73 year old psychiatrist who um had a normal neurological exam. She could do tandem gait, forward and back, no Romberg sign, um, she had good uh rapid alternating movements, but she had a subtle Hoffman's, she had multi-level cervical canal stenosis with some cord signal change. Um, and, um, there's some surgeons who, uh, will tell these patients, well, you know, listen, your risk of, of having a catastrophic spinal cord injury is really high and you gotta do something about it. And, and you and I just, you know, we, uh, didn't agree that that's the right way to counsel them. Can you, uh, sort of go over how, how you counsel these patients and sort of, um, calm them down? OK, you mean what I, the way I explained it? Yes, sir. You, yeah, the conversation you have with the patient, the first that I asked you is, if you had this, would you have the surgery? And you said no, that's right. So we should all go by whether we're religious or not, the golden rule because it applies to every single one of us. But What I do, I play a little game. I said, let's, it takes a couple minutes. I say let's play a little game and thinking through this, and I say, first of all, nothing we do is risk free. So you got to offload the liability as much as you can cause they could walk out of your office after this visit and slip on a banana peel and become a quad. OK, that could happen. Um, and you want to be be on record as saying, and sometimes it's good enough to say, when they sue you, it's good enough to say, I always say that. How do you know? Cause I always do it that way, and that's why I've done it this way for 20 some odd years, but bottom line is, I, I would say to the patient and family, um. Let's assume that if she's 70. Yes, sir. OK, that uh um 70 year olds as a group have about a 1 out of 50,000 chance of having a spinal cord injury in their lifetime, just for whatever reason, car wrecks, falls, skiing, whatever. And I said, OK, um, what if the rate was, um, You know, we cut cut that by 10, 1 out of 5000. OK. So, I doubt if there's a tenfold increase rate of risk. But even if there was, let's take it to a 100-fold greater risk, uh, than the general population and her age group, that's still 1 out of 500. And if you look at national databases, the incidence of catastrophe is about 1 out of 3 or 400 with with spine surgery of that nature. Do you buy that? Is that a is that a good game to play? Yeah, I mean, I the same risk of death right here 1000. There's 1000 chance of death. Did you hear that? The risk of death per year driving your car is 1 in 7000 per year, per year. So I would always tell the patients with radiosurgery that the risk of a secondary malignancy is about 2/10 of 1% in 20 years post treatment. And if you're worried about that, then you need to give me your car keys. Yeah, so, so that it's, it's interesting, we both have for different things have different ways of explaining it to people, and they say, uh-huh. So that that patient was told she needed surgery, right? Yes, sir, yeah. OK. So the surgeons that do that are using scare tactics, OK? And I drains my gears. I'm surprised that there's not natural history studies of cervical spondylosis that might even document the instance of catastrophic events related to trauma, but it's hard to quantitate the extent of compression. Mm There there's a very high incidence of people with cervical disease and depression that are completely asymptomatic. So it's it's very hard to. Bend. It's, it's will be very hard to, to know, you know, you know, what, what that would be. I think it's like 30% of people, there, there are some like good papers from the past that talk about that. You can get going here. What's that degree of asymptomatics, you would have some degree of cervical spondylosis or or compression or people with cervical. Stenosis, uh, they were all symptomatic, and they somehow followed the ones that they reported that they had had a trauma in the past 5 years, and the incidence of spinal cord injury as a result was no different than the group that did not report a trauma. Of course, there's lots of, you know, factors there, but there's at least something in the literature that says like minor trauma is not going to lead to, um, you know, a spinal cord injury, and then as far as car accidents go, just tell patients. Don't get into a car accident. decision making process is the elderly patient with a C2 fracture. Yeah. You know, there's camps that think that, you know, you gotta operate on these and other camps that say, man, you know, the complication rates so high. Um, so Jason. Yeah, what did you, you have commentary on the artificial disk stuff? No, I mean, we, we, we were talking about it yesterday. I think your, your presentation is very appropriate because it's not something we think about in terms of the biomechanical loads because the papers that are out there that level one studies, clinical trials show that there is decreased rates of adjacent segment disease in artificial discs at 10-year follow-up. But, you know, like we talked about those papers are in general funded by industry, um, and, uh, you know, there, there's bias involved as well. But it's very interesting about the 3%. Uh, annual risk of adjacent segment disease with laminoraminotomy equivalent to that with ACDF. See, it's like. These the people who did the studies for artificial discs totally ignored what we already knew. Because of how many studies that I show? 5, and they all basically show show the same thing. For for the you had mentioned going up to C2, is that only if you go down to the thoracic spine? Like if you had to do a 3 to 7 whammy. What's that? You uh there's an echo here. Oh, I'm sorry. No, that's OK. For you had mentioned going up to C2, don't stop at C3. Is that only for Fusions that cross the cervical thoracic junction. For the most part, yes. Um, I mean, I'll do a 3 to 6 fusion frequently. Um, so it's not, but I, I wanna get them. I won't do them frequently, but I will do them, and I wanna make sure that I get good alignment when I do that. And I wanna make sure that the C23 disc angle is gonna be relatively horizontal in the standing position. I ask you a bit. From a non-spine surgeon, you know, so I, you know, I very often surgeon, but he operates spine. Yeah, yeah, but, but I'm I'm not, you know, I very often do the posterior foramenotomy, and I just, you mentioned that. I, I, I think it's a great surgery and I was just wondering what, you know, how would you, cause I think for laterally uh located disc. With clear nerve root compression, when there's not a lot of calcification, it's just a, a great surgery where you do through the tube with image guidance. And if you can't get the disc out, you do it for anotomy, you might be doing just as much good. Yeah. So what is your like indication like with the patient that you would consider to do this procedure as opposed to like a ACDF central stenosis and uh and they have the kind. Foraminal stenosis. So, interestingly about that operation, I don't know if it's that way now, but it, you know, 1520 years ago, it was very regional, like in the Northeast, there was a lot of people doing uh frame anotomies, and in other parts of the country, everybody's doing ACTFs, um, so it's, it is a regional thing. The one operation though that I, I didn't talk about today is laminoplasty, which I am a huge fan of. Uh, for a lot of different reasons, it appears to in the Google Wallace study to be leading the pack, leading the pack being the pack being um ACDFs and uh cervical laminectomy with fusions, um, and in three categories, uh, um, return to the OR cost and health related quality of life metrics, um, and so. Uh, I'm widening my indications, as are a couple of my partners with, with, uh, uh laminoplasty, uh, for doing laminoplasty, and, um, you know, uh, we're we're seeing good results on it, and if you need to do another operation, you can still do either of those other two. You haven't burned a bridge, although. has anybody re-explored the laminoplasty here? No. I, I found it to be just riddled with scar, you know, it's very different. It was. So you, you gotta want to do it. It's easier to do an ACDF on top of it rather than a And so. Mhm. Mm. In post-op, and long term. No long term, but like if they present with a lot of neck pain, um, some, some surgeons prefer not to do laminoplasty because of the, the neck pre pre-op neck pain, yeah. I don't follow that rule, but I wanna ask, um, can I ask you a question? Sure. Um, we did a young woman, late 30s with an intradural extramendually entirely ventral. Um, tumor from C2 to C7 looked like a giant pendamoa turned out to be schwannoma. Um, but when we did the surgical approach, we did. Unilateral pediculectomy, laminectomy and pediculectomy, all the way down to C from C3 to C6. And then we cut this tumor into small pieces and literally pulled it out from one side. The patient. Uh, tolerate the operation, but post-op when she was fused, she ended up with a long skinny neck with severe muscle atrophy. OK, and committed suicide. Um, because of her physical appearance, um, why, why does she have a long skinny neck? Muscle atrophy, I'm not sure why. She was fused all the way, but I'm like from C2 to T1, you know, like 3. Well, that's a great approach. You could come at it from both sides too. Yeah, um. But she looked like, you know, the, the cultures Malaysia. I don't know which country it is where they banned the neck where the neck doesn't stretch, it's actually muscle atrophy, that's what she looked like. Have you ever seen severe muscle atrophy? No, no. I, I'll see it dorsally if you've over, you know, put a lot of tension on the muscles res muscles during tra, you know, traction injury, basically, ischemia. Right, well, we've gone through the lesson here and Deanendon from uh FIU Medical School is here and uh some of his colleagues in biomedical engineering would have Love to heard the biomechanics part because that's what Ed was really famous for was taking us through all these calculations and lines and numbers and angles and everything. I had a quite a few angles and things in this talk. That's why he was known as the engineer of spine surgery, but Ed, thank you for coming and thanks for a great talk. Thank you very much. Yeah. Uh, we have a small reception outside in the lobby, so please come and say hello Doctor Benzil. Thank you.
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