We'll talk about a couple of cases, let's see if this works, good. So hopefully by the end of this presentation you'll be better able to describe the evolution of using a 3D printer for arthroscopic surgery, how to create a 3D print, some implementation of these 3D printing for clinical practice and hopefully see the value of innovation in the surgical care. So actually just as a raise of hands, how many people use 3D printing for hip arthroscopy? One, two, three, okay that's great. How about how many people use ultrasound for hip arthroscopy? One? Oh, I need to ask. So the need, well why do you come up with these things? Well obviously we're all here, we know hip arthroscopy, sorry FAI is a leading cause for arthritis so we don't have to go into this. But typical space of hip arthroscopy is quite substantial, right? If you do a supine, you need a C-arm in there, you need your tech in there, you're wearing lead, you've got multiple people trying to see this, you've got multiple monitors so you're not bumping into your colleague. But for us, at least in Canada, we have limitations. I only have that C-arm in our main surgery or main hospital. We have a surgery center and the surgery center, we can see the picture on the middle there, that's a picture from the other corner of the room. It's so small, literally you can kind of reach out and touch both corners. There's no chance for us to renovate and get a C-arm in there. And so we needed to be able to try to do surgery in a very small area with no lidded walls and no x-ray available. So we went on, everyone has a component of injections that we do and we do know that ultrasound is a great way to do it, it's less painful. So since we do injections already, we thought, well we can use this for hip arthroscopy. And the nice part of using ultrasound is it gives a really nice two-dimensional view. You can get your plane perfectly and hopefully there you can see the femur on the left, the acetabulum on the right, and you can actually identify the position well and you can see the air arthrogram going afterwards. So the precision that we can use with ultrasound to get those portal placements is actually easier and seemingly faster to do than with x-ray. You get used to using this, it's very user dependent and you can see there in 26 seconds we can get both our portals in. So we did compare because we have different sites doing ultrasound versus those sites that we had x-ray. We compared the two, looking at almost 200 patients on each one, and what we found was we're actually more accurate with less femoral head scuffing or labral punctures when we're using ultrasound than when we're using x-ray. So we're quite happy that to get into the joint we can use ultrasound just as effectively and in fact maybe even faster using ultrasound than using x-ray. But that's usually not the question that people have because, great, we can get in there, I worry about how a resection goes, I'm determined because you know that residual CAM is probably the most common reason for doing revision surgery. And you can see Shane Ngo's paper here showing that, look, resecting the CAM not only is it good but it does seem to make outcomes better in the long term. So I think that data is coming out soon to be able to see that this is actually very important, not just what we want to do, but this does lead to clinical improvements. So conventionally we do x-ray, and I'll tell you, most of the time x-ray we can say, great, they have a CAM, they have a pincer, they have whatever. That gives us most of our information. I know lots of people do MRI, again looking for the soft tissue, but I've moved a lot towards CT because I'm realizing that I don't understand, even though I can see a CAM, I don't understand the morphology enough to do surgery to get a consistent result. Because when I look at my x-rays from previous, from 2013, 2014, when I thought I was actually doing a good job, it's no longer a good job considering from today's standards. So this is a typical picture that we have diagnosing, showing CAM, you can see the CAM there, but that's not the whole picture. The whole picture is where the CAM starts from, right? So if you're looking at this as a superior type of view or bird's eye view, you've got to figure out, does it start more anteriorly around the 1 o'clock position or does it start more posteriorly around the 11 o'clock position? And this is where that 3D model really comes in, because if you look at that video on the right, the CAM actually goes right up to that posterior, about the 11 o'clock position. So when I turn the 3D model back to an AP position, you can see if I resect back to where my pencil is or pen is, that will get the proper CAM resection when you're looking at an AP view. And when you're doing an x-ray and try to combine this with fluoroscopy, it really depends on the positioning of the leg. And so if your leg is just off a little bit, you can't get a post-op x-ray to recreate the same thing. You really need to see this in a three-dimensional shape. We'll go through a case to show this. This is one of actually our eMERGE physicians. He had hip pain, twisting after presenting at a conference, coming off stage, and then a hurt withstanding, no pain during activities, and then had another car accident to make it even worse. So he couldn't even lift his leg off for a labral tear type of pain. Otherwise, he's quite happy. Good strength, good everything else. Positive impingement test, positive typical labral signs. He got an x-ray as well as an MRI, and essentially they said no acute or concerning abnormalities. But when you look at an MRI, then you look in here and see good joint space. There's no subconscious cyst, no arthritis in this 50-some-year-old person, but they discovered this perilabral cyst. Now when we order an x-ray or a CT scan, you may be able to see or diagnose a rim fracture. From an x-ray that said nothing to see, to an MRI that shows a perilabral cyst, and now we see a rim fracture. When you do a 3D reconstruction, you can say that, great, now I can see this much more clearly. This stuff doesn't really appear as well in an MRI or a 2D CT. Now a 3D CT shows that rim fracture or OSAS tabula, but there's also a cam in here. If you look at 3D modeling, it's actually hard to see where the cam is, and I tried to depict with the arrow where the cam kind of starts from, from the interlateral corner. But when I do a 3D model, it seems much easier because I can actually lift it up, I can go in and look. I know you can scroll with your mouse, but it's a whole other story to be able to hold it, feel it, and like most woodworkers or carpenters, if you do anything like that, the best gauge is your finger. You're able to detect subtle changes much easier than with your eyes, because with eyes you need shadows to see these things. So again, I find using a 3D print is much better. So how do you use something like this? Well we published our technique of how to do it, because it's so hard to describe. You can see, hopefully with the right shadows on this 3D model, you can see how this shape on that cam, down that femoral neck, can be represented when you use those traction sutures just like Shane taught you, to be able to see down the neck. And I use an interportal capsulotomy, I actually pull those capsular sutures back and you can see right down the femoral neck using a 70 degree scope, and I'm looking for the exact same shape as that 3D print. So we do, again now with COVID, we're doing live surgery fees, this is for a Canadian Arthroscopy Association conference, you can see an overhead view on the top right. But this is that shape, this is that posterolateral corner, and in fact every patient has this. You can see this is that patient that we just described there, this is the posterolateral corner, and I'm trying to show you on the 3D model on the bottom right side to kind of imitate where we are, because I put this right beside me. I can just turn my head, look down, I change my head point of view, and be able to alternate these points of views to figure out where it is that I want to resect to. So I actually already identified it, I usually mark it, and my fellow does it too, mark it to see how far back it is in relation to a neutrally positioned leg compared to where the labrum is. So that's where I do my mark, and I actually identify the cam, pre-templated, to that same shape. And I'm trying to get this shape realigned and identify it with the cautery to make sure I get the posterolateral corner, I follow it anteriorly, and if you abduct the leg 30 degrees and forward flex it about 30 degrees, you can actually match where the labrum is, because the hip is a socket. You match where the femoral neck should be, and then you just follow the outline of the labrum all the way medially. And if you can rotate far enough medially, you can get all the way to the anterior cam as far as you want. So hopefully you can see here, we can see using the 3D model, showing you exactly where it is, I'm trying to show you the same position at every given time, to get the proper post-op x-rays, to get the planned resection that you want to get. So we actually wanted to figure out if this is good enough, because I have a site that has just ultrasound, I have sites that have x-rays, and we went through to be able to see what kind of resections we can get if we don't have fluoro, intra-opt, to be able to do this, but if we have a 3D printed model. And this is just submitted for publication right now, we tried to estimate good resections better than 55 degrees, and bad resections are having larger than 55 degrees. And what we found was, when we use conventional planning, which is including CT scan, right, so without the model, compared to those with 3D models, we're actually getting better alpha angles at the far medial aspect. That's where I find is, I don't see it quite as well on fluoroscopy, that very medial aspect of the cam. Laterally I can get, and you can see repeatedly, but medially, I don't get as consistent a result when we do this. We look at this both in DUN, frog leg, AP, and again, it's more consistent when you have a 3D model, just like when you do total joint replacements and they do all the robotic surgery, what they find is they don't make you a better surgeon, they make you have less error, so it's more consistent findings. Here's another example here, this is a 45 year old, had a fall at work, failed conservative measures, typical findings, again, main focus here is just a cam, just very minimal arthritis, we just were trying to focus on how we're going to deal with this cam. These are the typical views, again, AP, so AP didn't look like a cam there, but for a DUN, frog leg, and the false profile, you can see where it is, but it's tough to analyze where that cam's coming from. So would you get a CT to plan the surgery? We ended up getting a CT, and a 2D CT, this is where I can see the slices to where to do the resection for, but then I'm like, look, I can't plan this enough, let's get a 3D CT, and so this is, again, earlier in the practice, we got a 3D CT, I thought, look, I can see where this is, but we can only rotate it however the radiologists decide to make that rotation. We looked at the cam here for the resection, and what we found there, we'll speed through this a little bit just because we missed a bit, we do the traction sutures, again, this I think is essential, what Shane had taught us, we again, this is the posterolateral aspect, so this is down to 11 o'clock position, we're looking for that corner when it's adjacent to the labrum, and if we can get right to that area, when you can see this corner, you know that you can resect enough bone to that area, because that's what our planning was doing. So we look to do this, and this posterolateral corner, we can make the AP look good. Again, if you remember correctly, his AP of his hip actually looked fine. So now with the leg abducted 30 degrees and slightly forward flexed, we can follow the labrum all the way anteriorly, and then externally rotate the leg as well to get our outline for the cam resection. So again, here, this is with fluoroscopy, this is with x-ray during surgery, we're able to do this, we got the resections down and corrected to where we want, let me just fast forward to the very end because you can see what we finished doing, we get the resection all the way down to the base of the neck, you know, under fluoroscopy, where we're rotating around, we're quite happy with it, we did it at a dynamic exam, again, we're happy, we dealt with the capsule, and then this is our result. So we get x-rays post-op, first week, looks like a reasonable AP, looks like a reasonable frog leg, you know, at least up to the area that we want. He goes off for six months, and then describes he's increasing in pain, you know, a little bit more difficulty, so we get more x-rays. So these same series of x-rays again, we're like, okay, maybe there's a little bit more cam very dissolute, is that really bothering him? I don't know. We order a CT scan to take a look, and sure, you know, radiologist says there's a little bit of cam residual, but it's tough to see. So in the 3D reconstruction, looking at this, you're like, okay, maybe there's a little bit of cam inferiorly, it's tough to see, still tough to assess. But then with a 3D model, hopefully this makes a little more sense, actually, I thought I was gonna show that before, but when you compare a 3D model to your 3D print, to your 3D reconstruction on the computer, you can actually see it significantly better, because the shadows is what goes away. So the 3D model, I'm trying to orientate the same direction as what we're seeing arthroscopically. So we're looking at the lateral corner, you can see the previous resection, so this is a revision case of that same patient, looking down, I'm like, that looks pretty good. Looking anteriorly, I'm like, that's kind of what we saw before, but this is the difference. Now I can use and feel underneath there, there's a little more of a cam, more medially, that was missed. And even though on the fluoro, I was fooled, you know, I didn't have the foot rotated exactly perfectly, it's off by literally two, three degrees, and it didn't catch it. But now with the 3D model, I know what I'm aiming for, I'm aiming for bony landmarks, I'm aiming for that inferior recess, hopefully you can see the tip of that Apple Pencil there, it actually falls under that very distal medial cam, and it was way larger than I thought. And again, arthroscopically, you can actually see the difference here, so you're trying to get this flat to the femoral neck, and if you can see this, you can actually look for those things. So instead of looking on fluoro, I find that looking for the details that we find on the 3D print is more crucial and more helpful to make sure we get an adequate resection. And I think that's why we're finding it on our review of our things, why we're more consistent after a 3D print is because I'm looking for the bony landmarks instead of trying to chase after my fluoroscopy images. So in summary, hopefully you can see advanced imaging really is better for understanding anatomy. I really do think I understand it better with CT scans, even though I think I can see most of it with x-rays. Ultrasound can be safe as x-ray for assessing the hip, 3D model prints are useful for teaching and surgical planning, and then resections can be improved using 3D prints during surgery, and hopefully if you ever try one, you'll be able to see the differences with that. That's great, so thanks.

3D printing

arthroscopic surgery

ultrasound guidance

surgical planning

advanced imaging