Dr. Rebecca Blonde (3:09)

Yeah.

Dr. Scott (3:09)

Then we know is an A, B, C, D, E. When we're writing papers and I'm writing a paper and you're writing a paper, we know exactly what we're saying. Which I think is super helpful. That's step one because we can't speak the same language. We don't know if we're getting the same outcomes on the same patients. And so I think it's fantastic. So one question I have about this is, does this require you to get a weight bearing CT scan in order to be able to do this classification?

Dr. Rebecca Blonde (3:30)

It seems so, yeah, it does.

Dr. Scott (3:32)

So you think just based on your study or you just think in general, in order to really classify this, you need a weight bearing CT scan.

Dr. Rebecca Blonde (3:40)

Well, to object to objectively classify it in this way, you need a weight bearing ct, but I think you can use weight bearing radiographs. It's just, I think there are studies that have shown that weight bearing CT is more accurate than weight bearing.

Dr. Scott (3:56)

Sure.

Dr. Rebecca Blonde (3:56)

But in classifying, you know, pcfd, but specifically for these objective measures, we wanted to come up with values that, that were as accurate as possible and can only do that with weight bearing ct.

Dr. De Cesar Netto (4:08)

And that's a critique that we've had this study in general because not that many people have a weight bearing CAT scan, but all the data that Rebecca looked at was weight bearing CAT scan parameters. But the truth is for many of these things there are equivalents on a plain X ray too. So. And we've looked at similar of those in the past and you can almost take the same cohort she gave the example of hypovolgus we looked at that on a weight bearing CAT scan, but that's something you would easily measure on a weight bearing X ray. There's a few parameters that we had that were much easier and actually you could only see on weight bearing CAT scan, for example, the class C which, which is the forefoot supination. One of the majors she looked at was called four foot arch angle. And that's really a. On a coronal view of a weight bearing CAT scan.

Dr. Scott (4:45)

Yeah, I mean obviously a three dimensional analysis is going to be better than two dimensional and there are going to be some angles that can and should be measured in three dimensions. Right. That you just can't do in two.

Dr. De Cesar Netto (4:53)

But I will say one of the things we've done studies also to compare parameters on X ray and how they might correlate to findings on CAT scans. So there's going to be like a crosswalk for people so that you to your question, really can tackle these problems without a wavering. Cassie. And it's just a very helpful research tool.

Dr. Scott (5:07)

Yeah, for sure. We have one. It's fascinating. I use it some. I use it not as often as my partner does. Our radiologists seem to hate it, like really hate it because they think the quality of the image is not very good. I think the quality of the image is okay, but like if one of our lead muscle skeletal radiologists had their choice that they would get rid of the machine tomorrow. Do you guys have any trouble with, I don't know if quality is the best word but I mean it's obviously they're trying to use low amount of radiation so there are going to be differences in that and a sort of quote unquote standard CT scan. Do you think that causes any difficulty with your interpretation of it versus a regular ct?

Dr. De Cesar Netto (5:42)

I, I can comment. I mean the resolution is probably a little bit less, but it's gotten way better as we get different iterations and now actually the wavelength CAT scans come up to the hip. The resolution at the hip is probably a little bit less, but it's still excellent. And actually one other thing they're working on and getting better at is what's called a digitally reconstructed X ray. So you can take the wave brain CAT scan data and it's not a true CAT scan, it's tomogram. You're just seeing things in different planes and you can actually make an X ray from it.

Dr. Scott (6:06)

I think that's fascinating.

Dr. De Cesar Netto (6:07)

It's gotten way better.

Dr. Scott (6:08)

So I think we're gonna get to.

Dr. De Cesar Netto (6:08)

The point where you probably don't even need an X ray.

Dr. Scott (6:11)

Right? Yeah. Because I mean, as you guys, you know, it probably mentioned most people are going to follow people with a weight bearing CT scan. Right. But if you had to able to sort of take that data set and turn that into an X ray, which I've seen before, I mean they were doing this 15 years ago when I was in medical school with CT scans and re engineering them to look like X rays, I think that could be helpful. And that way you may be able to take the information you got and correlate that even better with a plain X ray because it's in the same patient, you can measure the same angles on those two different study types, which. Fascinating. So yeah, again it's a great project. So what do you think the next steps are on this project?

Dr. Rebecca Blonde (6:46)

That's a good question.

Dr. Rebecca Blonde (6:48)

Well, I mean, I think what's helpful for this is now that we can kind of compare or look at severity of PCFD and look at treatment and how the changes in those objective measures may contribute to patient reported outcomes. Okay, yeah, no, if you dial in, you know, a certain amount of correction, does that help?

Dr. De Cesar Netto (7:08)

Yeah, that's a great idea. So one thought would be to get a weight bearing CAT scan at six months afterwards and see are we correcting each of those classes? Rebecca in her presentation this morning was saying, and we believe it's like each class usually drives with it a certain surgical treatment. The class A for example, is usually you're medializing heel slide. The class B is a lateral column lengthening. So we can use the classification then to drive the specific surgical treatments, the amount of each of those osteotomies that you might do and then see what it looks like after to see if we got it back to a normal range.

Dr. Scott (7:37)

That's really what I'd like. I mean I'd like. And maybe there's help from AI here. You know, basically I put my X ray my way. Brings CT scan into AI. It not only says, okay, you got class ABCD 1, 2, whatever, it does a whole classification and then we as researchers with you guys develop what is the algorithm steps do I need to do. And then, and maybe it's you do some and I do another because I can tell you for most of my flat feed I'm pretty algorithmic. It's a gastroc session, medial space of calciotomy, cotton osteotomy, FDL transfer, posterior tubal tenotomy. I probably do an Evans in 1 in 10 to maybe 1 in 20 patients. And I mean I Check promise scores. I publish my results. My patients do pretty well. I mean, of course, nobody has perfect results. I certainly don't. I have people that still hurt it nine months and I'm not happy with it. But I would say overall, I think my rate's pretty good. And Scott, you may recall, I think we did an interview, maybe it was five years ago now. And I think your algorithm has changed of how you were taking your own flat foot from five years ago. I think we had one of these podcasts, even as Caesar on maybe a couple of years ago, I said, you know, a lot of the focus has been on the angle of the subtalar joint. Well, actually makes some sense to me. The angle's off and that allows maybe the subtle joint to kind of spin and rotate. That causes a flat foot. Because we really don't know. Chicken or the egg. Is it the posterior templal tendon spring ligament? This angle, we don't know. Again, this is like going to the heart doctor saying, I have chest pain. We have no idea what caused it. It's great. So, but like with surgery, we're not addressing the angle of the subtalar joint. Nothing we do is addressing the angle of subtalar joints. Like, so you're doing subtalar joint osteotomies. I don't know. Right. But I'd love to know that.

Dr. De Cesar Netto (9:05)

Well, it's a workaround. I think AI is right on too, because one other thing we're looking at right now independently, is we're developing a smart, like a patient specific. The smart flat foot.

Dr. Rebecca Blonde (9:15)

I was going to bring that up too, as when you brought up AI Just, you know, if you plug in a CT scan for a patient and it can tell you using these thresholds how much you need to correct and you can have like a patient specific treatment options or all the options for that particular person.

Dr. Scott (9:30)

Yeah. Because I mean, right now when I do my cotton, I just feel the front of the foot. I mean, it's subjective. I mean, I do this a lot. I think I have a good idea. I've had people, I've overcooked it. I've definitely had people have undercooked it. I'd like to know, oh, you need to put in eight and a half millimeter wedge. Okay, can do. Right. But I think all of us want to treat our patients better and give them the exact correction they need. And I just don't know that we have that yet. But anyway, I really appreciate yalls work. I think this is step one. Step one is we have to all agree on what we're talking about and I think this is going to help that. So I get really appreciate Yalls work on this. I think it's fantastic work. Congrats on a major award and thanks for spending some time talking with us about it. Really appreciate it.

Dr. Rebecca Blonde (10:04)

Thank you.

Dr. De Cesar Netto (10:04)

Thank you. It's an honor.

Podcast Host (10:06)

Thank you for listening to the AOFAS Ortho Podcast, a Convey Med production. To learn more about joining our dynamic community of highly skilled orthopedic specialists, visit aofas.org.