Thanks, Don, I'll set this up. Thanks for having me again. It's always great to come to the AANS and I've been here for, I don't know, it seems scary about two decades now, and it's great to be here. I think this is a topic that's gonna, not my topic in general, but the whole practice clinic was gonna be one of the issues, one of the important issues in spine care for the next decades to come, because this transition from open surgery, non-navigated, fluoroscopic-based surgery to navigated robotic surgery probably will be the game-changer we'll see, and we can discuss later on how this will affect our way of doing things. I do have disclosures, and we do get research grants from BrainLab, and I do some consultations for them, some presentations for them, so it should be, but I don't think it's gonna affect my talk. Well, spinal navigation, you'll know, standard use placement of pedicle screws, there are nice studies out there, if you use navigation for pedicle screws, your accuracy is gonna be higher, particularly in the thoracic spine, as you see here in the middle, and there are different types of navigation you can use with interoperative imaging, you have isocentric C-arms, you have O-arm, you have interoperative CT scanners, and they all, because the accuracy is a little higher, increase your perfect positioning rate a little more. And what I'm gonna talk about mainly is an interoperative CT-based image guidance, we have a full-blown CT in our setup that we use for our navigation. And again, just to remind you, there has been an evolution, and we are right now, for us, an interoperative CT-based, and robotic should be ideally the next step to go. So I'm gonna talk about this mainly, and obviously the opportunities and limits, you have to be aware of this, may vary depending on the setup you have. So if you just use different ways of interoperative imaging, or surface matching whatsoever with navigation, you will have different pros and cons, so it's not, navigation is not automatically like navigation. So we use it also as a standard, not only for pedicle screws in open surgery, but for MIS procedures, and basically in MIS, all our pedicle screws are put in using navigation, and personally, the biggest advantage is that I don't wear lead anymore, and I don't use fluoro for my MIS cases at all. Because I also navigate my cases if I need to, to be honest, most of the time I don't even do that anymore now. So this is particularly important for us, and I mean, if you talk to some of the older orthopedic surgeons, primarily that are now in their 60s, if you look at their rates of thyroid cancer and stuff like that, it's actually something that should worry us for our young generation to come. Expanded indications, that's the main topic I'm gonna touch upon. Obviously you can use it for difficult implants, I'm not gonna say it necessarily, an iliac wing screw will be a difficult implant, but if you go from a S2 iliac wing, sometimes they can be challenging to really put them perfectly, so if you use navigation, it's very straightforward, you don't have to worry about your fluoro setup, and this can be done very nicely and very accurately without much issues. Something that we don't do that commonly, but we sometimes do an anterior C1, C2 fixation, which if you're, I don't know if you're familiar with the technique in general, it's not used that commonly, but if you use the regular standard technique with C1, C2, C1 on both sides, you actually have to put the pharynx quite far to the other side, and those patients, almost all of them complain of dysphagia, and what we do now, we would use the ipsilateral screw standard way, and the other screw goes a very long way through C2 and then into C1, so we don't even cross the midline in our preparation, which makes this a very straightforward surgery, but this is a difficult screw to put in, to really enter the C1 perfectly, two and a half or three centimeters on the other side, is very challenging, if you use navigation, it's very straightforward. So these are some of the difficult screws we use it for when we talk about expanded indications, this is just, you don't see it well, it's a bit small, but you see how long the screw is in C2 before it actually enters C1 on the other side. Obviously for deformities, this is again a discussion, this is just a regular case where we have a low dose protocol, because this is an issue that we can discuss, whether we should do those with navigation and interoperative imaging, because they are like, this is a fifteen year old girl, came quite late to us, and if you talk about those kids, radiation exposure is an issue. Implant positioning, sometimes this is a pretty nasty case of an L4, L5 destruction, at this point in time for unknown reason, it was not really an infection, and I put this cage in from the front, sometime before, obviously didn't do what it was supposed to do and went someplace else, and if you have destructions like this, it can be very challenging to know where to put your implants, and if you have navigation for these, you actually end up putting the implant exactly where you want to put it on the rest of the solid bone that's there, and this can be very, very challenging to identify this perfect location of your implant if you don't have navigation. So the final result you see on the right, and this worked well and it healed sufficiently. What we also do is navigated interventions, what we love to do now, actually not that many cases, but if you have patients with metastatic disease of particularly C1, C2, and we don't want to go for big surgery or whatever, we do trans-oral vertebroplasty, again, navigation, you don't even have to worry about the mucosa there, very straightforward, you position your needle and then inject cement, that's what we still do with fluoro obviously, to see how the cement goes into C1 and C2, and this is something that surprisingly works well and then the patients usually irradiate it and do quite well. This is the post-op result for this lateral mass, and that looks okay. And something that we didn't think of in the past, for example, I mean, many of you will say, well, why would you need it for any decompressive surgery? What we love to use it now for is actually an L5 is one for amyloid stenosis in some of those 80-year-old massively degenerated patients where there's not even any space between the L5 lateral process and the ala of the sacrum, and you don't have a hard time, you don't know where to go, huge facets, and if you want to do an MIS decompression on those sometimes old and fragile patients, we now use navigation. This is a different case. You see, this is a case where we had a very much anterior, I would say extreme lateral disc herniation, severe L5 radiculopathy. At first, it wasn't even diagnosed because the radiologist didn't see that quite for anteriorly located fragment, and we would now put the, just put the reference arc on iliac crest, and you can identify directly where you have to go and have a very straight approach. And as I said, we tend to do this for amyloid stenosis in those patients quite often, and then use a tubular approach that's just navigated. And another case that we've started to do things on, this is a patient who had again a very severe L5 radiculopathy. Again, delayed diagnosis of what the problem was, this anterior osteophyte actually encroaching on the L5 nerve root, and we did an anterior approach, put the reference arc on the anterior iliac crest, which again also works quite straightforward, and then went in there through a mini-alive, lateral alive approach, going to that osteophyte, which you see nicely on these images, and then this is before and after. You can just drill out this osteophyte, open up the L5 nerve root, and have a very minimal invasive approach solving the patient's problem. And this can be quite challenging. Obviously, you can do this without navigation, but if you do it with navigation, it's just so straightforward that you have a very easy time to find an area of exposure. Something else would be, this is a patient with an unusual, I don't want to say it's an OPLL, it's just a multi-level anterior disc disease in the thoracic spine. He was myelopathic, and doing this from the front, I felt like it would be a rather large operation, so we did it from post-laterally, and again, if you do this navigation, you can quite nicely attack this and do a nice decompression of the spinal cord in this case, and the patient did very well. Resections, obviously, if you have some lesions, or this is a deformity case, where we used the navigation both for the implant positioning, which can be a challenge in these patients, and then also from the front, to resect the vertebral bodies in the front, and really optimize your cage positioning, you can also use navigation for this. And when I look back about where we came from, in neurosurgery, basically as just doing decompressions, tumors, etc., etc., this is one of the cases that for me shows best how we have changed and advanced. This is a now 18-year-old boy, and he had seven operations, if I remember correctly, for a neuroenteric cyst, from the age of three to the age of 10. It always recurred, and he was always operated from the back through a long-standing laminectomy, and now, after not having had an operation for eight years, he comes back with increasing spinal cord syndrome. This is the images that he got, and you obviously see that there's a recurrence of the neuroenteric cyst, and you also see that there's a deformity of the neck after the laminectomy, and this is a patient that we would now do in a combined approach. So the first step we did, we did a PSO of T1 to correct the deformity and stabilize him from the back, again, using navigation for this, and then after realigning the spine, we went in from the, so this was the image after correction of the deformity, doesn't, does look just a little straightened out, obviously, and then we came from the front, did a copectomy, and took out the neuroenteric cyst from the front, because after seven operations from the back, I felt like it wouldn't make much sense to come from the back again, and you will not get a cure, and it seems like it worked quite well interoperatively to get the neuroenteric cyst out, so this is the final image now, and the patient is doing quite well, and you addressed both in a two-step fashion the deformity and the resection, and again, if you use navigation for these, you can exactly determine how large you're going to do your decompression, how large you're going to do your exposure, both from the front and the back. The same is true for primary bone tumors, this is a case of an originally quite large Ewing sarcoma, it was biopsied, and then received adjuvant chemotherapy, this is six months later, so all the epidural component is gone, and this is what you have left, and in these patients, it can be challenging interoperatively to know how far the tumor actually went into the pedicles, because that's something you don't see because of the adjuvant therapy, and to be sure that you actually know exactly how far to go, so obviously, the pedicle screws are put in that way, but also the osteotomies to open the canal and take out the whole vertebral body is then navigated, so you're absolutely sure you used the old MRI pre-therapy to know how far the tumor went, then you look at the new MRI, and this is something that you would not be able to, so this is image fusion, and then you decide where you make your cuts, and this is the end result after vertebrectomy, and this is the, actually we put the bone in the CT scanner afterwards just to have a look at the resected vertebrae. So, in summary, and this is just supposed to be an introduction on what you can do nowadays, we have transverted from going different ways, so spinal navigation, we use it routinely for pedicle screw placement, I think everybody is aware that this is what we do, and for MIS, the procedure is quite clear, it has improved accuracy, it supports screw placement in complex anatomy, I agree with those critics out there that say if you only use it for very complex cases, you may be in trouble, because you should also use it for regular routine cases, but I think for your complex cases, it's even more worthwhile. It allows navigated interventions like segment augmentation biopsies, which we would do now using navigation and interoperative imaging. For me, very, very importantly, it simplifies decompression procedures, and a lot of you may say, well, I can decompress a neural frame, and L5 is one also without navigation, I agree, but it's just putting your tube there and just drilling exactly where you know through that lateral part of the facet, you know exactly how much you have to take, and this just makes it much more straightforward and easy for me. And for bone and tumor resections, obviously the same is true, there still are some limitations, and I think Dr. Sheeban is going to talk about the cervical spine, the cervical spine for me is still a limitation, the mobility makes it difficult, but there are some tricks to overcome this, and I'm also still for interoperative imaging, particularly in pediatric cases, a little worried about radiation, and that's the limitations that we still have there, and so I think I'll leave this for the discussion thereafter. Thank you very much. Any questions to this? Yeah? No, we do that in brain lab. And we would, for the tumor cases, we would just only focus on this one vertebra, and that, we do the automatic image fusion, which works quite well. Which sometimes a challenge if you do pre-op, or pre-therapy, and then post-therapy, so you have to check this again, but it does work quite well. Great.

navigation

interoperative imaging

spinal surgery

pedicle screw placement

minimally invasive procedures