Okay, our final talk of the session is Paul Park. He'll be speaking about cervical osteomyelitis and kyphosis correction. So, I appreciate the opportunity to give this talk. I'm actually filling in for Dom Cork. And I'm certainly not Dom. He's much taller than I am. And I think he'd probably do a bit better job with this. Well, actually a much better job with this talk since it's his. But I think I have a good handle on it. These are his disclosures. It comes from the same group that Tim Adamson is in. And they're a good group. They do a lot of good surgery. So, I'll preface this talk in that it's not heavy literature-based at all. It's really a case presentation on what can happen with cervical discitis and osteomyelitis long-term if it is not treated surgically. So, just a little bit of a background on cervical kyphosis and sagittal alignment for the most part. Global alignment refers to the interrelationship between cervical, thoracic, and lumbar spines from the pelvis to the occiput. The pelvic incidence sets the ideal magnitude of lumbar lordosis, which correlates with thoracic kyphosis and subsequently correlates with cervical lordosis. And the implication of this is everything's interrelated. You know, when I first started training, and I'm not that old, we just looked at different regions. If it was lumbar, it was lumbar. If it was thoracic, it was thoracic. If it was cervical, it was cervical. We didn't really think about any other aspect of it. But what we know now in terms of deformity and spinal alignment is everything's interrelated. So, one thing that you do in one region can certainly impact another region and maybe potentially cause another problem. So, the cervical spine allows the largest range of motion in the spine and plays a critical role in maintenance of horizontal gaze. And when it comes to cervical kyphosis, horizontal gaze is a separate metric. It's extremely important. It's actually one of the primary metrics that you want to assess, and it's important to the patient because it is directly associated with the degree of disability that the patient will have. So, when it comes to measuring cervical alignment, there are a number of different measurement systems. One of the most common is the C2C7 Cobb angle. That gives you your cervical lordosis. The C2C7 sagittal vertical axis is, I would say, a newer metric that's become more popular. And it's analogous to your C7 SVA that you would assess for global spinal balance when it comes to thoracolumbar spinal alignment. It's just directly analogous to the C2C7 vertical axis. What's considered an abnormal parameter when it comes to C2C7 SVA is greater than 4 centimeters. It's associated with a worsening neck disability index. And going back to your horizontal gaze, one of the most, I think, oldest but still used measurement for horizontal gaze is your chin-brow vertical angle. And this is really measured on pictures, you know, like lateral photographs more than anything else. And so, you know, this has been associated with disability as well. And Don puts out the metrics less than 4.8 degrees or more than 17.7 degrees. I think these are actually kind of actually fairly shallow metrics because if you look at a chin-brow vertical angle here, it's a line, like, drawn parallel to your face and then a vertical. So, a chin-on-chest deformity would be 90 degrees. So, in his parameter, 17, more than 17 degrees is considered some sort of disability. I think that's a little bit mild, but there's different definitions. And this shows you the C2C7 cob angle on a T1 slope, which is analogous to your public toe. Just more diagrams. This one is showing your C2C7 SVA, and that's just a drawn line from the mid-cervical body to the back of the superior plate of C7. Again, these are just metrics that I think you should keep in the back of your mind, particularly when you're dealing with some of the cervical deformity. And it will be relevant to the two cases that will be presented. This is a slide just showing the degree of severity when it comes to C2C7 central vertical axis. And this is from the AIMS classification for deformity. And this is just a snapshot. There are actually many more modifiers and curve types. But this is just showing, you know, just briefly that C2C7 SVA of less than 4 centimeters is greater than zero, which means normal. Moderate severity is actually 4 to 8 centimeters. And severe degree of, I guess, deformity is greater than 8 centimeters. The cervical lordosis T1 slope mismatch is analogous to the lumbar lordosis, the pelvic incest mismatch that I think everybody has heard of when it comes to the thoracolumbar spine, but it's a direct analogy. Again, these metrics just tell you how severe it would be. Again, this is relevant to what we're talking, although we're not going to go over the parameters per se in the cases that are presented. So this is a 53-year-old man who presents with neck pain requiring long-acting narcotics, an inability to lift his head and stand straight, and really has no quality of life. And this is directly due to the fact that he has no horizontal gaze. And you'll see that in a minute. So his history is notable for radical neck dissection for tongue cancer, followed by chemotherapy and radiation therapy. His post-op, of course, is complicated by cervical dyskitis, which is treated non-surgically with bracing and IV antibiotics. And this is typically done for dyskitis and osteomyelitis with an epidural abscess, for example. And I think that would be very reasonable. But there's some long-term implications of doing that in terms of the osteolysis, eating away at the bone, getting inflammatory response. And you can certainly have an alignment change with that. So on exam, he's non-vocal, no evidence for myelopathy. Motor strength is pretty good. His exam is actually pretty good. And you see that a lot with these cervical kyphotic deformities where they're not really having too many issues in terms of myelopathy or even maybe pain. The biggest problem is they're looking at the floor. And that's where most of their disability comes from. So a number of imaging was obtained, flexion-extension radiographs and a CT. Here are the X-rays. And you can see it's a pretty profound deformity. So here's cervical 2, 3, 4 is destroyed. Here's 5. And you can see it's almost a 90-degree angle. And here's his chin on his chest. So his chin brow vertical angle would be probably close to 90-ish. This is his extension film. So he can extend a bit. So there's a little bit of a gap here. And here's the scoliosis X-rays. You can see long cassette film. You see his head is resting on his chin. And, you know, 90-degree angle. And the CT shows it looks like it's probably a fixed deformity at this point. There's no disk space. It's 4, 5. So this is a fixed deformity in a fairly neurologically intact patient. So you could only hurt him actually neurologically, right? You can't improve him, right? So this operation is due to a functional disability. So the question is, what do you do? A number of options. You probably list some more. But Dom lists several here. You can do a 360 or a circumferential operation. You start anterior, posterior. Posterior and then anterior. Or you can do a 540. That would be three position switches. Posterior, anterior, posterior. I don't think anyone probably would do anterior, posterior, anterior. But that's an option. You could also do a pedicle suppression osteotomy or Smith-Peterson osteotomy. The PSO really, you know, in the cervical spine really should only be done at C7. Just because of the vertebral artery, the risk is just too high of getting a vascular injury anywhere above that. So that would mean actually not treating a direct pathology, but treating in another region to hopefully get his alignment improved. Whereas the first two treatments would be directed at the site of pathology. So I'll go back to the x-rays here, or CT. How many in the audience would do 360? So one person. Would you do anterior, posterior, or posterior, anterior? Anterior, posterior. And can you comment on why you would do anterior, posterior? Absolutely. I think that's definitely, I think, the correct reasoning. I think a lot of people would choose posterior, anterior, posterior if they thought the posterior aspect of the spine was fused. Because if it was fused and you started anterior, you wouldn't get much correction. But in this particular example, you're absolutely right. The facets don't look fused. So I think it would be mobile. So doing an anterior, posterior operation I think would be very reasonable. So I'll tell you that Dom slightly disagreed. He did posterior, anterior, posterior because he was concerned, you know, I talked to him a bit about it. He was concerned that it wasn't released enough posteriorly. So he wanted to make it as loose as possible to maximize his anterior correction. So he started posterior. And he did decompression. He did Smith-Peterson. So these are complete facetectomies. And that definitely will loosen up the spine to a certain extent. And you could add some screws at the same time, but with no rods. So that would be your posterior aspect. And then he came up front with an anterior corpectomy with an expandable cage with anterior plating. And then he went back to the posterior aspect for fixation. Here's a few examples from his case. So posteriorly, he didn't add all the screws. He did definitely release the or did the facetectomies. You can see the facet joints aren't there anymore. There's cuts through them. So that definitely will result in a posterior release. And then anterior release is coming up. And I give him a lot of credit. You know, someone who's had neck surgery and who's been radiated, really difficult to get good anterior approach safely. He was able to do that. And you can see he's put some distraction pins in. Since he's done that aggressive release posteriorly, distraction will work here. And so with the corpectomy and an expandable cage will help you get even more correction. You can see he's done a pretty good job in terms of realigning the spine. And this is the final construct. I think he's just showing the anterior and posterior and CT, which shows a good sagittal correction. We'll place an implant. Okay, good. And then the next case, a little bit different, but the same problem. So a 53-year-old man who presents with progressive neck pain followed by onset of dense quadriparesis. He's had a post-radical neck dissection for parotid tumor followed by chemotherapy and radiation. It's the same kind of theme here. He's supposed to have, of course, was complicated by progressive swelling difficulties and neck pain. And he was diagnosed with cervical discitis, which is treated non-surgically with bracing and IV antibiotics. You know, unlike the other person, this patient is myelopathic, all right? He's got weak extremities, upper motor neuron signs, paresthesias. I would argue if you look at his MR, I probably wouldn't have treated this non-operatively because he's got an epidural abscess. And I think that's the reason why, you know, he has neurologic problems, not the discitis or the deformity itself. But he certainly does have a cervical deformity. You can see the cross-sectional views here. Here's a CT. Again, this has been allowed to fester for a while. And so, you know, if you get through sort of the acute infection, it's a fusion-promoting type of event, you know, all infections if they're in a disc space. And a lot of people feel that's due to the inflammatory factors that are released with the infection. It's sort of an osteogenic type of reaction. So if you get through that acute phase, it will lead to fusion. So this is a fixed deformity again. So, again, treatment options here. So we have anterior loan, posterior loan. Again, the 360s, the 540s, the pedicle obstruction osteotomies. Any takers now? Do you think the facets are fused? So right here. Oh, up here, 3, 4. Okay. Yeah, I mean, I think there's a little bit of a, yeah, it looks like there's a little bit of fusion mass. Actually, to be honest with you, when I first looked at it, I would have probably just gone anterior-posterior. I didn't really think about it. But I agree with you. There's a little bit of a fusion mass here. Although, you know, with this being free, you could probably get some motion. And it depends if you do a two-level corpectomy or not, obviously. If you do a two-level corpectomy, you go beyond that. Two-three is okay. So I'll tell you what Don did was a 360, anterior-posterior decompression stabilization. I think you have to do the anterior because he's got epidural abscess as well. So you definitely need a decompression. You definitely need a corpectomy. So he did a corpectomy of C3 and 4, with an expandable cage from 2 to 5, and ACDFs below that, and posterior fixation. And what he noted, and this is actually, I think, happens a lot with these cancer patients, is there's an esophageal fissure that directly led to the infection. And so that had to be repaired. So this obviously turns out to be a combined operation, which is challenging. You can see, though, with an anterior approach, he's able to get a decent amount of correction. And I think a lot of it comes here. I think you're correct. It doesn't look like this facet separates that much at 3, 4. But he's got some at 4, 5. I'm sure at 2, 3 it moves a bit, too. And there's his final construct. You can see he's also using an expandable cage here. I have a question. Who uses the – I know everybody probably treats infection with interbody work. Does anyone use PEEK if they're going to put an interbody in for infection? Okay. Everybody will use titanium? Who uses allograft? Anyone? Okay. I mean, it's historic. I think allograft is very reasonable. It's just an advantage of an expandable – well, titanium is considered bacterial static. And you can treat an infection adequately with titanium. So all titanium, I think, is what most people do. But allograft actually is a very reasonable option as well. It's just you can't get expansion. And a lot of people, the expanding capability just makes the corpecting a bit easier. You may get a little bit better realignment. So those are the two cases. And there are a lot of pearls he had with these cases. And, again, these are specifically for dyskinesis and kyphosis, spinal inflection leading to sagittal plane deformity. And so non-surgical management is effective in about 75 percent of dyskinesis cases. But non-surgical management may result in significant deformity and morbidity. And these patients need to be followed very closely. And I think that's totally true. In most cases, kyphotic deformity is fixed and requires combined approaches, anterior-posterior or posterior-anterior-posterior. Use a pre- and or interruptive traction. And, unfortunately, I didn't comment on that so much, but I'm a big fan of traction. I think it's very easy to apply, and it may help with the realignment. And it's not that much effort. Posterior osteotomy must be complete. And he's talking about the releases in that first case. If you just do partial releases, you won't get as much deformity correction. So you want to do complete fascitectomies. You need to take advantage of new technology like expandable cages, favorite angle posterior lateral mass screws. Technology can be helpful, but it's not a replacement for surgical, obviously, technique and experience. And we just discussed this. I think titanium definitely over PEEK. PEEK, you know, it'll develop a biologic film, and it really is a nidus for infection to just fester. So I don't think anyone would use PEEK here. And that's it. Thank you.

cervical osteomyelitis

kyphosis correction

interrelationship between spine regions

horizontal gaze and cervical kyphosis

measurement systems for cervical alignment