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Primer on Pediatric Spinal Deformities: Neuromuscular Scoliosis, Kyphosis, and Spondylolisthesis

Andrew Jea and Jean Pierre Mobasser

March 11, 2017

Transcript

- [Jean-Pierre] Welcome to another session of AANS Operative Grand Rounds. This is part two of a series of pediatric deformity surgery. I'm Jean-Pierre Mobasser with Goodman Campbell Brain and Spine in Indiana University. And today we have with us, Andrew Jea who is our Chief of Pediatric Neurosurgery at Riley Hospital with Indiana University. Good afternoon, Andrew.

- Good afternoon, Jean-Pierre. It's great to be here again.

- Okay. So I see we've got a lot of slides to cover, so let's jump right into it. We spoke previously about adolescent idiopathic scoliosis, and now we're gonna talk about the neuromuscular scoliosis.

- Right. I think that this is probably the group of patients that are most commonly seen by pediatric neurosurgeons for other reasons other than spinal deformity. So, this group of patients should be very familiar with, to pediatric neurosurgeons.

- Do you see that orthopedic surgeons see these patients equally as much or less so?

- Yeah, I think that orthopedic surgeons, their bread and butter are the adolescent idiopathic scoliosis patient population. I think that this is a little more complicated patient, a little more fragile. Complications are a little bit higher. So, this is where I see pediatric neurosurgery making the biggest inroads as far as starting cases in spinal deformity.

- Okay. And you have a few subheadings listed here between polio or motor neuron disease, cerebral palsy, and myopathic. I assume see cerebral palsy is gonna be the bulk of these patients?

- Cerebral palsy and myelomeningocele, spina bifida cases, a little different than the adolescent idiopathic scoliosis group. Like I mentioned, they're a little more fragile. So, the threshold to operate should be a little higher.

- Okay.

- The treatment really is not as involved as far as decision-making as adolescent idiopathic scoliosis. Treatment here is a very long segment fusion, usually from T2 to the pelvis.

- Well, let's dive in and talk to some of these treatment options, and some of the things that you have written down here. Let's talk about the incidents associated with paraparesis or paraplegia compared to the adolescent idiopathic scoliosis patients.

- So, usually this group of patients will usually have a pretty profound neurologic deficits even prior to surgery. The way you hurt these patients is with blood loss, with postoperative infection, with wound healing problems. So, that's where the challenges is to optimize this fragile group of patients prior to surgery. Neurofibromatosis is a special group. It's a very difficult scoliosis to treat. It can be broken down into dysplastic and nondysplastic. Dysplastic, meaning it's a very sharp angular dislocation on the spine, and these should be treated very aggressively, even very early on in life. The nondysplastic is just like idiopathic scoliosis.

- So, let's talk a little bit about spina bifida and how that relates to these patient populations.

- Sure. Just a little brief introduction about spina bifida. It's an anatomic defect as well as neurologic deficit. Usually the levels kind of match up. Anatomically, they're bony abnormalities which need to be kept in mind, especially with surgery. There are no posterior elements. They're usually splayed to the side. Closure is, I'm sure that residents have seen myelomeningocele closures. It's a layered closure soon after the baby's born. It was really revolutionized after the introduction of the shunt. Prior to the shunt, the prognosis for children with myelomeningocele was horrible. You would close a defect, but then they would die from hydrocephalus. And I should also mention at the same time with urologic, improve urologic care, this has also improved the life expectancy of children with spina bifida.

- I certainly don't wanna get a sidetrack, but while we're on the subject. What is the current literature saying about these intrauterine repairs of myelo patients that has become a growing procedure over the past decade?

- So, fetal repair of myelomeningocele is actually backed up by level one data prospective randomized study, the MOMS trial. I believe that was published in 2012, 2013 in New England Journal of Medicine. And since then, it's spawned the growth of fetal centers that are usually part of children's hospitals. So, it's a very interesting history of how the MOMS trial started and everything. But very clear evidence that the efficacy of fetal closure for myelomeningocele in terms of avoiding shunt placement.

- Do you feel that or is there information supporting that there's been less scoliosis development with patients that have a fetal repair or is that unclear at this point?

- That's unclear. That's not really been born out by the study, by the MOMS trial. They didn't focus on that at all. Indirectly, as a secondary outcome, there is some improved motor function with the patient population that underwent fetal repair. So indirectly, with improved neurologic function maybe less spinal deformities in that group.

- All right. Let's go through the deformities that we see with these spina bifida patients.

- Sure. I mean, you can see anything under the sun basically. The most common is scoliosis. Probably followed by a congenital kyphosis. Sometimes the spine can look like 180 degree hairpin turn or any combination of the two. As we keep saying, these kids are very fragile and the indications to operate should be pretty high. There was a good study from the rehab hospital in Toronto that was associated with sick kids that basically looked at what improved after a scoliosis surgery in neuromuscular kids. And the only thing that they found that really made a difference was sitting balance. Nothing else, functionally or cosmetically, made a difference. So, I think that the threshold to operate has to be very strict. And these are some of the indications for surgery.

- One question. We know that a lot of these children are gonna progress on to needing surgery. Is the goal to wait as long as possible before you have any problems so that they go down their growth cycle for fusing their spine?

- Yeah, I think because they have so many other systemic problems going on, you wanna wait as long as possible. And not until your hand is forced. Not until you see one of these indications on the screen right now.

- And is there one of these indications that you have listed that is more important to you than others, or they all pretty much equally important?

- I think they're all pretty much equally important. I think I mentioned sitting balance was the only one borne out by the literature. Probably if you get progressively worsening pulmonary function, that'd be a very important reason to do surgery. Especially, you get restrictive lung disease. It translates back to the heart and leads to a possible heart failure, which could be life-threatening.

- So treatment options, we've talked about these before with the last series, but why don't you go through these again as related to neuromuscular patients.

- Sure. So, observation is always an option. If you go to spina bifida clinic, you could probably pick if you're a threshold operator was very low. You could probably pick any patient there and say, "Well, this patient needs surgery." But again, these patients are very fragile. So, your surgical indications, your surgical threshold should be very high. Bracing, which is an option in the idiopathic scoliosis group, is probably not a good option in these neuromuscular patients, specifically the myelomeningocele patients. Because they're usually insensate and they're prone to pressure ulcers with prolonged brace wear. So then, you're left with surgical stabilization infusion. And like I said, there's not a lot of decision-making in that. Usually if you decide to operate, it's a long segment fusion. T2 to the pelvis is the standard. This is the recommendations for adolescent idiopathic scoliosis. I think the wrong thing to do is to extrapolate from this and apply it to neuromuscular patients. And decide that once it hits 40 degrees or more, that's an absolute indication for surgery. That just isn't the case. There's a lot of other factors that need to be taken into consideration before taking a very fragile child, complex child, to surgery.

- Do you wanna talk about the Risser grading system or is that coming up a little bit later?

- I think we have a little cartoon coming up a little bit later.

- Okay.

- Right here, as a matter of fact. So basically, it's just a way of judging skeletal maturity. You start at Risser 0. And the iliac crest apophysitis, calcifies, ossifies over time, until a Risser 5 when they're skeletally mature. So, I would say that if you wanted to operate and we're worried about growth, probably a Risser 3 or more, you're probably pretty safe. There's not much growth remaining and you won't lose much height if you operate in that threshold.

- So, let's talk a little bit about deformities in scoliosis.

- Yeah, absolutely. So, the scoliosis that you usually see in neuromuscular patients is a little different than idiopathic scoliosis. These are usually very broad C-shaped curves that involve the entire spine. Scoliosis is by far the most common deformity that you see in myelomeningocele, but you can see others as we mentioned. The second most common are these congenital kyphotic deformities.

- Yeah. And we'll get into that in a second. Do you see a certain level of the spine affected more than others with the neuromuscular patients?

- No, it's usually the entire spine. Usually, there's a very poor ability to maintain any sort of posture. So, the deformity usually involves the entire spine. The most severe severely effected segment is usually the part that has that anatomic defect, where you have the neural placode. That's probably the most severely effected portion of the spine. But really, the entire spine is affected. Here's just a pic-

- [Jean-Pierre] And I I know you and I.

- I'm sorry.

- I know you and I touched on this last time, but can you sort of give everybody an update as where we are right now with the growing rods and how those are used.

- Sure. A lot of attention on growing rod constructs as it applies to early onset scoliosis. The idea of being you wanna maintain some sort of normal growth while treating the deformity at the same time. So, these really all fall under a type of fusionless surgery or limited fusion surgery. What's picture here is actually a VEPTR, vertically expandable prosthetic titanium rib, described by Dr. Robert Campbell to treat respiratory insufficiency. Dr. Campbell is an orthopedic surgeon. Since then, people have kind of extrapolated its use. And not only taken it from a rib to rib construct, but also rib to spine, rib to pelvis, spine to spine. So a lot of different uses for VEPTR nowadays. Overall with these fusionless techniques, the biggest problem has been wound problems because you don't want to expose a spine. Because in a child, you expose a spine, you get autofusion. So, you try to place this instrumentation right underneath the skin, in the subcutaneous layer, which results in a lot of ulceration, wound breakdown, wound infection. So, it's still a difficult problem.

- Okay. All right. And a little bit about myelomeningocele as related to patients and their age.

- Right. So basically, what we're trying to show here is that the worst the neurologic level, the worst the paralysis, the higher the potential errors there is to develop a spinal deformity, both anatomic and neurologic.

- And I know that we're gonna get to spondylolisthesis near the end of this talk- But is there anything-

- [Andrew] Yeah.

- You wanna mention in relation to spina bifida?

- No, I don't think that you would treat spondylolisthesis or spondylolysis that you see in myelomeningocele any different than you would see in another patient.

- Although, I guess the difference being that usually it's a lower lumbar segment where they have scar tissue, the neural placode, and the previous surgery they had at birth.

- Sure, yeah. Technically, it might be more difficult. The decision to operate probably isn't that much different than any other patient.

- Okay. And let's talk a little bit about kyphosis within this patient population.

- Sure. Not a very common problem. Again, not as common as scoliosis. When it does occur, it's usually pretty severe. I think we talk about some reasons why this occurs. And again, it's that whole splaying of the posterior elements, which results in a displacement of the usual extensor muscles of the back. And it turns them into flexor muscles, which kind of worsens that kyphosis over time.

- And just remember, we have some adult surgeons who are a long way away from the whole congenital process. When the spine forms, the neural placode folds over on itself. Basically, isn't it in the mid spine? And then, it runs superiorly and inferiorly. And that's why we see the incomplete arches at the top and bottom of the spine.

- Correct. Correct. When the neural placode forms into a neural tube, it kind of zippers up and down, rostrally and caudally.

- And then, let's talk about compensatory curves.

- Sure. I think that it's what you would expect to find. You have a pretty severe lumbar kyphosis, which should be lordotic, and you get a reversal of the thoracic curve. The thoracic spine should kyphotic and becomes lordotic.

- But in adults or even in some adolescent scoliosis patients, you may not have to incorporate the compensatory curve because you know it's going to self-correct, but these patients are different.

- Yeah. The difference here is these are pretty rigid curves. If we had to fix a lumbar kyphosis, I wouldn't use a long segment fusion to address a compensatory curve, just the kyphotic portion. I think that functional-

- [Jean-Pierre] So, do you do do you do stretch films, bolster films to look and see if that's still a mobile compensatory curve before you make a decision?

- I don't. I haven't found that to make a big functional difference in these patients. This cartoon is a nice smooth curve, kind of over simplified. And how one potential way to treat that, which is similar to a pedicle subtraction osteotomy, but rarely is it that mild. I'm not exaggerating when I say that a lot of these kids have 180 degree curves, basically a hairpin curve. I think in the next slide, we'll probably see a real life example. And there it is. So, this is a patient that was treated with a kyphectomy. So basically, the apex of the kyphosis, probably three or four vertebral bodies were removed. And we instrumented above and below, and basically lever down the remaining segments of the spine to get bone on bone contact. To try to smooth out the spine as best as possible and get soft tissue coverage. So usually, the indication in these cases is a breakdown of skin over the boning gibbous that just doesn't heal. It's a non-healing ulcer. And what you wanna do is you wanna give as much soft tissue as possible to get coverage over that area.

- How often do you see electrophysiological evidence of problems with the spinal cord when making a correction in a situation like this interoperatively?

- So usually, these kids that have these bad kyphotic deformities, I'd say 100% of them are paraplegic. They have no function below that level. And many times, I don't even use monitoring for these cases. If I do monitor, it would be to, for the upper extremities, to make sure we don't get a brachial plexus problem during prolonged positioning. This is right.

- Yeah. And we don't really talk much about Scheuermann's disease as far as children goes. A lot of us as adult surgeons think about this as something to address when it's an older person. What is your indication for surgery in an adolescent with Scheuermann's disease?

- So, probably the same as an adult. So I think that there's a radiographic threshold, and then clinical. So, clinical is when there's just an intractable back pain. The radiographic threshold is when the curve, when the kyphosis reaches about 75, 80 degrees, we would recommend surgery. And the interesting thing, Jean-Pierre, it'd be interesting to know if you see the same in adults. The back pain isn't over that the deformity. The back pain is where the lumbar lordosis is. So, these patients are pitched forward, and then their lumbar spine tries to lower those, to pull back their head and get a good balance over the pelvis. And it just overstress or overworking in the lumbar spine that gives these patients pain. Do you see that same thing in adults?

- You can. The one issue with adults is because a lot of them who have these problems may be not as well conditioned as children, is their back muscles, even in the thoracic spine, will tire out as the day goes on because they're essentially out of balance.

- So, same. Almost the same. And the other thing we see in kids is that usually they're very, very thin. Usually, they're hypermetabolic. Their muscles are working overtime to pull them back and they lose a lot of weight despite taking in a lot of calories.

- So, let's talk about TB a little bit. Obviously, not something we see that commonly in this country.

- Right. I think usually you think of this as a third world country type of problem. But we see a little resurgence of TB causing problems, at least in the pediatric population. Not only spine problems, but also TB meningitis causing infarcts in the brain, as well as hydrocephalus. So surprisingly, there seems to be a little bit of a comeback for TB.

- Do you find that you have to do a more anterior work in a TB patient, just because we need to clear that infection versus the other kyphotic issues we're talking about?

- Yeah, absolutely. I think if you do have to operate in TB, it would be to address the infection and try to clear out that infection, and maybe shorten the chemotherapeutic course to treat the TB. As a positive, if there can be a positive, in TB spondylitis is that you can do this all from the back. And usually the bone is melted away in the front. So once you access the body from the back, it usually just sucks away because the bone is pretty much melted away by the infection.

- Obviously, just some pictures here showing the kyphotic development in these patients.

- Correct. Yep. So you were talking about Scheuermann's kyphosis, which is an adolescent disease. But certainly, there's congenital kyphosis as well from segmentation and formation abnormalities of the vertebral bodies. And these kids can sometimes present at a very young age.

- Let me ask you, I did a hemivertebra in the lumbar spine at L4 that was coronally only offset as opposed to kyphotic, and went posteriorly to reloosen and release all the tissues. Then anteriorly, and then back posteriorly again. And still really had trouble getting good alignment across that hemivertebrae, despite really releasing a lot of bony tissues around that area. Do you struggle with children with hemivertebrae surgery?

- No. If you're able to resect that hemivertebrae, they usually reduce very nicely. And you're actually able to get away with a very short segment fusion instead of having to do fuse them long. So because of that, there's a movement actually started by Juergen Harms to address hemivertebrae as part of congenital scoliosis at a young age. And to resect that hemivertebrae, just do a short segment fusion and be done with it.

- So I guess, and I just wasn't qualified to do the operation. I never should have done it in the first place.

- No, not at all. You're an excellent spine surgeon, Jean-Pierre.

- So this is obviously a pretty prominent one. How often do you see people come into your clinic who have such a prominent kyphosis like this, or is this an extreme example?

- This is an extreme example. The usual case is that adolescent Scheuermann's kyphosis and they basically have a hunchback. And complain of back pain like we were talking about or cosmetic problem. And this is just talking about the segmentation or formation abnormalities that might result in congenital kyphosis. And here's an example of a formation problem on the left and segmentation abnormality on the right.

- Do you find one or the other is more difficult to correct?

- Well, I think that the formation abnormality, once you're able to resect that abnormal vertebra, you're able to get a very nice correction. Whereas the segmentation, so basically a fuse bar. And that's a little more difficult to deal with. And sometimes, you may end up doing a vertebral column resection in order to get a correction of that kyphotic deformity. Here's an important point. Again, a pre-op point, pre-op workup. When you see any sort of congenital spinal problem, whether it's scoliosis or kyphosis, you should look at other organ systems. Particularly, the spinal cord and the renal system, the heart and the GI system. This is just again going over formation and segmentation problems in congenital kyphosis.

- And we've sort of been through treatments before. Now, we can talk a little bit about the different types of osteotomies. Do you have a particular osteotomy that you tend to use more than others or is it really depend on the geometry of the issue?

- I think it depends on what you're trying to correct and how much you're trying to correct. I think as listed Smith-Peterson, Ponte, PSO, and VCR, kind of that goes in order of how involved these osteotomies are. And as you go from Smith-Peterson to vertebral column resection, the risks also go up as well. But I would say that my go-to three column osteotomy is pedicle subtraction osteotomy more than more than anything else. We kind of talked about Scheuermann's kyphosis here.

- Yep. And we talked about the bending forward and the backache as well.

- So I think we've covered most of that.

- [Andrew] Correct.

- Let's talk about rare complications.

- Yeah. So unlike scoliosis where if you were at 90 degrees of more of deformity, it can start to cause restrictive lung disease. and then, heart failure. That rarely occurs with kyphosis. Usually with this sagittal deformity, it doesn't really affect lung function, pulmonary function at all. And therefore, it doesn't affect heart function at all. I have not seen a severe case enough that would cause lung or heart problems. I don't know if you have Jean-Pierre, or not.

- And let's talk a little bit about imaging and preoperative planning. Do you do a lot of your planning based on x-rays?

- No. Our orthopedic colleagues are very happy with, and I think we discussed this at our, on our last video, who are happy doing a preoperative workup with a plain radiographs only. I think it's much more thorough to get a CT scan and MRI as part of the preoperative workup, preoperative planning. I do think full spine x-rays are important to get an idea of global sagittal coronal balance. But I would, I start planning what type of instrumentation to put in based on what we see on CT scan and MRI. MRI, just don't wanna be surprised by anything deeper inside, like spinal cord abnormalities or anything like that.

- Okay. Do you wanna briefly touch on measuring these kyphosis angles?

- Sure. So basically, you just use a cob, a measurement. It's basically the superior endplate of the rostral end of the deformity and the inferior endplate of the cuddle end of the deformity. And you want your cobb angle to span that entire deformity. And we went over the regular, the normal measurements for thoracic kyphosis, which should be anywhere from 20 to 40 degrees. So anything more than that, you're starting to talk about hyperkyphosis. And you can see these wedging of the vertebrae, which is very tell-tale of a Scheuermann's kyphosis.

- So when you look at somebody like this, who has an 85%, 85 degree curve, do you start to think in terms of surgical planning? Okay, this is gonna require more than Smith-Pete's or I can do Smith-Pete's at multiple thoracic levels, and probably get a good correction here.

- So, because this curvature is usually very kind of broadened and gentle, I think that Smith-Peterson osteotomies at multiple levels would be a good option here. And by the book, they say that every millimeter of Smith-Peterson osteotomy that you do, you get a degree of correction. And I think that's about right. I never really measured it out postoperatively but that's how I would plan how many Smith-Peterson osteotomies I would do.

- So, it's a little hard for me to tell for sure on this x-ray, but it seems like a lot of the kyphosis is occurring right in this mid region here. So, with this one lead you more to thinking about a VCR in that particular area, 'cause this almost seems from here to here, like there's not much angulation or here to here.

- Yeah. I think it's dealer's choice, Jean-Pierre. For a case like this, I would still do Smith-Peterson osteotomies. So, here I would think about maybe five levels. That's kind of epicenter at the apex. If you get five to 10 degrees for each osteotomy, I think that results in pretty nice reduction if the patient starts at 85 degrees. I think a good point to make when you're thinking, when we're talking about preoperative planning is how do you know where to start and where to end your instrumentation? And I think very importantly that the end of your instrumentation should be where your sacral plumb line hits the last lumbar vertebrae. I think if you stop behind that plumb line, I think that you're in trouble. I think that you're very prone to develop distal junctional kyphosis. And I think rostrally, you just wanna get to the end of the cobb angle, the rostral end of the cobb angle.

- Do you think that that could be affected though, for example, if you have a very focal kyphotic angulation in the mid thoracic spine, where a lot of the curvature is quite severe? It could make that plumb line look like it's in front of the entire spine, even if the lumbar lordosis was fairly normal.

- I pretty much follow that religiously, Jean-Pierre. I looked for where that plumb line is. And I think if you're worried that is something being thrown off by the x-ray, then I think it just means either getting another x-ray. Making sure that the patient is standing in their natural neutral position. Maybe with their knees bent a little bit. Maybe having them hold their arms to their chest or out, so that nothing else is throwing off what your measurements are before surgery.

- I was looking at your differential here. And while we see a lot of spinal infections with adults nowadays due to poor nutrition, uncontrolled diabetes, IV drug abuse, I would assume that discitis osteomyelitis is still a lower incidence in children.

- It is, but we're taught to think so if a child comes into the emergency room with fevers, back pain, and even just with that, the first thing that crosses your mind is the discitis osteomyelitis.

- Okay. Basically thinking you just wanna make sure you're not missing something critical. So, let's talk about back straightening exercises. How effective are these?

- Probably not that effective, but it's just something that unfortunately nowadays insurance companies want you to go through before offering surgery. I think it's probably correct. If it's a very mild curve, maybe postural reeducation can help with relieving a lot of that back pain. But I think that, once you get beyond 40 degrees, so once you get into this hyperkyphotic range, I think it's unlikely that physical therapy alone is gonna help or even bracing. I think bracing is just a temporary measure.

- So, when you look at a patient like this who had an 85 degree curve, and it ends up being 52 degrees when it's corrected, which looks quite nice, do you want to get them to 40 or less? Is that your goal?

- No. That's another good point. The goal of surgery is just to get them back into balance. Get them back into sagittal balance so that they're head lines up over the pelvis. That's the main goal of surgery.

- So, let me ask you, when I look at this, I have to assume, it's hard to see here, but the plumb line is somewhere out there, which really falls all the way down to the lower lumbar area. And yet, you stopped higher up, kind of like what I was talking about.

- So the sagittal plumb line that I was referring to actually is a vertical perpendicular line through the posterior superior corner of the sacrum. So if you were to draw a line like that. and-

- [Jean-Pierre] Oh. Sorry, I misunderstood you.

- Yeah. No, I think that this is great to point out. But I think what you did point out the C7 plumber, you can clearly see that this patient is out of balance. They're positive. They're pitched forward. So the goal is just to get that lined up over the pelvis. And functionally, they should improve this lower back pain that they probably experiencing before surgery, should go away. You can see how thin that patient was as well, which was my other point. That these muscles, these paraspinal muscles are working overtime to try to maintain any sort of sagittal balance. and they're hypermetabolic.

- Yeah. I don't think we need to get into the elderly, but yes we see lots of positive.

- No. This is something that you can talk to us about Jean-Pierre.

- Well, let's stick with the kids today. And spondylosis and spondylolisthesis, this is a great topic to include because I think this affects the adult and pediatric surgeons. It's a big part of our practice as adult surgeons.

- Yes, surprisingly, it's a big part of pediatric spine practice also. One of the more common visits to our clinic is for pars defect that may or may not have been discovered incidentally.

- So, this is a good topic 'cause you and I were talking about this a little earlier. In fact, I've sent you one of my friend's children to look at. How do you decide when you've got an 11 year old who has a pars defect that only bothers them when they play tennis, but she wants to play tennis four hours a day. If she's not playing tennis, she's asymptomatic. What's the discussion with the family in a situation like that for you?

- So I think with anything in the pediatric spine, you think conservative first. So, you see if a period of bracing would help, a period of physical therapy. But assuming they've gone through all of that, and they come back to you with this history that when they're not playing tennis, they're feeling fine. When they're playing tennis, they get back pain. So, it becomes a quality of life issue. And I think that if tennis is an activity that they love to do, then I think that our job is to try to get them back to doing what they love to do, improving their quality of life.

- So, I think that it makes sense in kids. The issue I had early in practice was treating some 15, 16, 17 year old girl who had back pain and had a pars defect. And I did several pars repairs that I thought clinically went extremely well, was very happy with the surgery. But none of them did very well. There seemed to be this psychological barrier to success in those patients.

- That's a little surprising. Usually with young patients, especially if they're 15, 16, especially if they were active before and maybe there were athletes or cheerleaders, and they ended up with a pars fracture, they're usually very motivated to try to get back to that level of activity after surgery. And there's not a lot of the secondary gain that you usually see with adult patients.

- Yeah, it was interesting. In retrospect, one of the patients was a getting a scholarship for running to university. And I think she had very little interest in running and had difficulty telling her parents that she didn't wanna run in college.

- So, right. So, maybe kids do have some secondary gain as well.

- When you're working up a pars defect, are you happy enough with an MRI and a x-ray or CT that shows it, or do you feel that a bone scan adds value to determining the activity going on at that area?

- I don't. That's not a typical part of my workup. I'm happy with dynamic x-rays, CT scan, and MRI. I don't usually get a bone scan or SPECT. I think I just included that just for completion sake, because there are some spine surgeons that go ahead and get that. Do you get that normally Jean-Pierre?

- [Jean-Pierre] I usually do not. Again, I do more of what you've said, but I think there've been certain cases where getting a little more evidence of activity, if somebody who couldn't get an MRI for example, there was a role in that situation. So what other interesting twist on spondylolisthesis or pars defect 'cause I did some work with the NFL and at the NFL Combines. And in talking to one of the surgeons who Hank Feuer whose been doing it for 25, 27 years at the time, he was evaluating people that were being drafted into the NFL who had pars defects. And what they found in looking back in their data on people who had been accepted into the NFL and their longevity of their career, they found if these patients had minimal back symptoms and their disc health looked good at the level, at the five, one level with an L5 pars defect. they could have a successful NFL career. But they found that if they had a pars defect with some back symptoms, and had a significantly degenerative disc at that level, they rarely lasted beyond one to two seasons in the NFL.

- Well, that's good evidence to have. I didn't know that. I don't know if that's Dr. Feuer's anecdotal evidence or if that's actually published somewhere. I think that that would be very helpful.

- I do not believe that that information has been published, but I found it fascinating in talking to him about that and learning a little bit about that.

- No, absolutely. I think you always struggle. The child that's minimally symptomatic or they improve with conservative treatment. And now, the discussion with the child and parents is, well, can you go back to play football or some other contact sport. And I guess what I've been telling them is go ahead. Go ahead and go back to your normal activities. That's the whole goal of anything that we do, whether it's conservative or surgery. But just know that symptoms may recur and if they do then we might be talking about kind of more intensive treatment like surgery. But I always said that just kind of based on not much evidence, just my own kind of personal beliefs and personal opinion. So, it's nice to know that's been observed by an NFL expert out there.

- Well, and there is some overlap because now we start to address these motion sparing techniques, meaning when do you fuse across the junction for L5 pars defect and when do you just repair the pars itself. And so, I think this is where the overlap occurs between what he saw in the NFL and what we're talking about with the pediatric population. So tell me, let's first talk about the two real options for a pars repair, the direct pars repair versus the rod and laminar hook and pedicle screw construct.

- I'll just kind of just as a disclaimer, I almost always treat with pedicle screw fixation, an L5-S1, if it's an L5 spondylolysis. I have not done a direct pars repair or a rod and hook at the same level to try to spare levels. Quite honestly, I've been very happy. And I think the patients have been very happy with the L5-S1 fusion and not lost much mobility with that single level fusion, despite it being at L5-S1. So, I don't know if you have experience with the first two surgical options Jean-Pierre, and what the outcomes have been.

- I've done all three. And kids with the healthy disc, I've tried to really avoid fusing across a mobile segment if possible. I did not think that the direct pars was a very successful operation, in the sense that it's a very small bone. It's atrophic. And the screw can take up basically the entire bony cross-sectional area where the defect is. So, I didn't find that healed as well or had as good a result. I have had good results with placing a pedicle screw at L5 and then a hook underneath the L5 lamina. And then, basically compressing after cleaning out the scar tissue, and decorticating the pars defect, and basically realigning and reconstructing that. So I do think for somebody in my mind now that I put all that information together, if they have a healthy disc, there's no instability, I do like the laminar hook and pedicle screw construct in that situation.

- That's interesting. Do you ever do a laminectomy for decompression when you have spondylolysis, spondylolisthesis or are there certain characters?

- So for, so for adults, well I was talking about children just then. For adults, most of these people that I see, they have degenerative disc. They have a spondylolisthesis and they have instability. So, all of those patients are a different situation. And a lot of those patients I'm doing decompressions. So, if I wanted to do an indirect stabilization and put a graft in anteriorly, then I could put in percutaneous instrumentation posteriorly. But when I talk to patients and bring up the complications or the risks associated with an anterior surgery, whether it's a direct anterior versus a lateral, and I tell them I can do the whole thing from behind through the same incisions and avoid all those anterior complications, very few of my patients want me to choose the anterior options. I've come to believe that the people that do a lot of anterior surgery or lateral surgery probably tend to play down some of the risks associated with that procedure. If they're gonna have to go posterior anyway, because all you're doing is adding a lot of risk on, and so what patient would choose that.

- Makes sense.

- So, how often are you dealing with a case like this?

- So, high grade spondylolisthesis doesn't occur very often, thankfully. When it does occur, I think that it's full hearty to think that you're gong to reduce, get a hundred percent reduction of the spine and get a normal looking spine afterwards. I think that the goal of surgery is to keep this from continuing to slip and to decompress the neural elements. So just my opinion, I think that the goal of surgery here would be an insight to fusion and decompression.

- Yeah. And so, it's interesting 'cause I've done this operation both ways. And I've done high-grade slip procedures where we put a transvertebral cage anteriorly through L5 across the sacrum with an ALIF at four or five. And then, posterior construct with screws at L4. And then, sacral screws that go up and cross into the L5 body, and had really fantastic results. But I do worry about the sagittal imbalance that we're not correcting in this situation, and is this patient better off and getting back into alignment. So, I've done the opposite surgery where I realign them. I believe the literature is very accurate that when you try and reduce these, which I've done, I think there is a much greater risk of L5 neuropraxia injury associated with that reduction because it puts a fairly large amount of stress on that L5 nerve root, which has been in this certain position for years and years. And so to suddenly realign, I think, is very, puts significant risks to that L5 nerve root.

- I agree. I agree. And that's how I would advocate for the insight to fusion without an attempt at reduction, and maybe a posterior decompression if there are radicular symptoms that the patient has.

- I did see a presentation in Portugal last year by Dr. Koretsky from Nottingham in England in a case like this, where they are using the bone scalpel to shave off the dome of the sacrum with the very little blood loss. And then, create more space to realign that L5 on top of the sacrum by essentially cutting off that top corner dome of the sacrum. So, it's easier to slide L5 back into alignment. And I thought that was pretty interesting technique.

- Sounds interesting.

- One thing I do find interesting in this list is I don't feel like I've seen a lot of people with these problems who have cauda equina, and I think you mentioned how uncommon it is. It just seems because a lot of times they've separated posteriorly that there's not a lot of central stenosis in these patients. It's mainly a foraminal issue.

- I agree. I agree.

- Do you ever do anterior approaches in children for these kinds of problems?

- No. I think in kids, we try to do everything from posterior. The only anterior approaches that I've done has been for sacral tumors, where you wanna kinda get separation with the pelvic organs and vessels from the tumor.

- So let me ask you, we went through a very interesting evolution of spinal infections at our trauma center. Very different patient population, obviously. And we had a higher infection rate that we wanted. We made a lot of modifications. This is about the time that the vancomycin powder articles came out. And then we did a little, a few things beyond that. And we now have the protocol for our open surgeries where we're thoroughly irrigating out the wound with a Clorpactin irrigation via pulse lovage at the end of the operations. And our infection rate has dropped dramatically with a very high risk patient population for infections. Is there anything that you're doing in children to try and reduce the surgical site infection?

- There's a huge movement to standardize infection prevention, and this can be done institutionally or across institutions. I don't think it matters. I don't think that there's a particular step that's the most important step in a bleeding infections. I think that the most important thing is that everyone just decides to do the same thing. I think that that's probably the most important lesson to be learned from infection protocols and quality improvement. This is just an example of kind of what we went through at the other children's hospital that I was at. And at Riley, there's also a standardized infection prevention protocol that we've been following that's very similar. Again, I think that the point here is it doesn't matter what steps you put in there. I think it just that everyone does it the same way. I think basic tenet of quality improvement is that standardization decreases cost, but more importantly improves clinical outcomes period.

- Yep. And I think that a lot of this list sort of goes over things that we've talked about. The one thing I think is funny as we as surgeons will spend six or eight hours doing an operation, but then when we have to wait the five minutes to irrigate with three liters, we're all reluctant to do that.

- Jean-Pierre, do you believe that there's one particular step that's more important than others like vancomycin powder or anything like that?

- We're looking at our literature right now here. I think, my personal view, is that the thing that's helped us the most is actually the Clorpactin irrigation. Clorpactin, there's very little evidence or literature on it in spine, but it's very common in genital urinary irrigation. They used it since the 1950s. And Clorpactin is hypochlorous acid, very similar to chlorine. And they've been using it with the very safe, safely in bladder irrigation since the 1950s. And somebody in our group got the idea, so we started doing pulse lavage with it in our wounds and all these trauma patients, the infections, the diabetics, the smokers, and have really had a dramatic change in our infection rate, but we change more than one variable at a time. So it's hard to say that this is it, but I do believe this has had a dramatic effect on our infection rate.

- I'd love to find out if your fusion rates have changed because of that.

- Absolutely. It's a great question. And so, we're looking at that too. So if I do an inner body fusion, what I've typically been doing is I plug the annulotomy defect with one by one Cottonoid while I'm doing all the irrigation, just to reduce the risk of that Clorpactin getting down into that disc space. If we're doing it with the posterolateral fusion, we're doing that before we lay our graft down. And we're following that liter of Clorpactin with a liter of saline afterwards to irrigate it all out.

- Got it. So other possible complications, especially in very young kids, are these soft tissue defects with instrumentation erosion through the skin. There really isn't a pediatric spinal instrumentation set. All the instrumentation that we use are adult size spinal instrumentation. Companies, unfortunately, just haven't found it profitable to cater to a very small segment of the patient population. These are some of the complications that we can get. They're very uncommon. This particular child is a child with cancer. And has actually gotten radiation to the skin, unfortunately, right where we had to do his spine surgery. And he's had some difficulty with healing and instrumentation erosion through the skin. It's also, this is probably doesn't need to be said, but difficult to put a pedicle screws in sometimes in these severe deformities, because the pedicles could be asymmetric with very hypoplastic pedicles on the concavity of the curvature. And this is something we can just go over very quickly. Basically, looking at our pedicle screw accuracy rates. And not unsurprising, the highest misplacement of pedicle screws were in a spinal deformity.

- Let me ask you, Andrew. Are you a navigation user?

- I am. For the longest time at my other hospital, pediatric hospital, where I came from, we did not have navigation, spinal navigation. It probably wasn't there until the last year that I was at this other hospital. I use it for every single case except for cervical spine. And I've done the same thing here at Riley. I think it's silly not to use a tool that could ensure safe outcomes.

- [Jean-Pierre] Yeah, we-

- [Andrew] Please tell me these navigation also, especially since-

- Oh, yeah. Well, I don't think there's many screws placed in central Indiana without navigation. It's really become the mainstay for a large percentage of surgeons. And in fact, it's interesting. Our group was the predominant user early on, and there were several orthopedic spine surgeons in town who really didn't think it was necessary. And now, all of them are using it. And so, I believe that it's made surgery much safer for patients and almost eliminated the need for return to an operating room for a malposition screw. 'Cause in 13 years in practice, I have not taken a patient back to the operating room. Now, I've changed plenty of screws over that time when I've seen the postop span and decided that I didn't like the position, or I've left them alone knowing that I may not like the position, but it's in a safe location. But I've never left the operating room not knowing and I can't imagine going back to that.

- That's great.

- Well, I think we're wrapped up, Andrew. Thank you very much. Really appreciate you spending this time doing this. And maybe we can find another interesting topic to talk about.

- Now, that was fun. Thanks a lot, Jean-Pierre.

- All right. Have a good day. Thank you everyone.

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