Dr. Rhett Hallows demonstrates RI.HIP MODELER, a preoperative tool designed to assess spinopelvic mobility. It allows surgeons to evaluate patient-specific constructs and visualize potential implant impingement during activities of daily living.
Yeah, hip modeler is a program that was developed to help us place acetabular components in an appropriate position based on a patient's spinal pelvic mobility in referencing a functional pelvic plane when they're standing. So first thing we're gonna do here is we're just gonna search for our patient name. Uh And this patient uh is gonna be named ABC. So we search um we see this come up, this um we're just gonna click on it, make sure we have the films that we need to do to, to proceed which we do. Um And so once you see everything you need here, we're gonna go up uh hit the arrows, move to the next side, next slide. Um Before it'll let you proceed, you're gonna have to pick the side that you're gonna be operating on and we'll just pick the right side. Um We're gonna pull our films through entry. So if we search the little cloud, the cloud is gonna be um our quant database and here's our films for our patient. Um And so if we just click on the film, it's gonna give show the film and we're gonna have to pick which one. This is, so this is a sitting film. So we'll just click on the sitting. It's gonna bring us back to the previous screen. We're gonna click on the other film, which is our standing. So we'll click our standing film. We're gonna save that. And then once we go here, we're just gonna go keep working through the workflow. So next arrow, um it's just gonna give you a, a warning screen about things that you need to look for and make sure you can see clearly before we move forward. So we'll just hit, OK. Uh And so as you can see here, we have the standing and the sitting lateral radiographs. Uh And so we'll start on the standing film and uh the first dot The number one you're gonna want to put on the end plate um of S one. So we're just gonna let you allows you to zoom in. So my pointer uh close to S one and then above that is gonna be a zoomed in screen so you can get, you can accurately place that one. The second one. We're gonna go with the inferior and plate of S one. Once again, we're just going to find that we can kind of come down zoom in really nicely and put it right on there. Uh Second points we're gonna look at are the uh pubic synthesis and A SI S and we'll start up at the top at a now this is gonna be your A SI S and you're gonna want to identify both sides of the A SI S. So this is one side of the A SI S. This is the other side. You're gonna wanna put a point somewhere in between, right in the middle of between those two. So if this is one, there's the other one, we're gonna put that right in the middle, the second one, you want to put center of the pubic synthesis just gonna be there. Uh And that gives us our standing sacred slope. And now we're gonna come over to our sitting film. We're gonna do the same thing here. We're gonna find uh the end our end plate. S one N plate. I'm gonna put that one there. We're gonna come and do that same mark of in fear in plate here. Just make sure we got that good. And so, uh from there um gives us a few numbers. Um It's gonna give us our standing and our sitting sacred slope. It's gonna tell us what the, the change is, which is for. Uh And based on the categories, this is considered a fused spine which you might expect to see with somebody with spinal hardware in place. Uh We're just gonna save that and then from there we go to the next screen. So here what this is gonna show us is we're gonna go through um And you can pick if you want uh you probably have preoperative templated this. And so you're gonna go in and put the implants that you've templated for here. Just do our dropdown menus. Um R three neutral liner. Um We'll just go with a 32 head ball. We'll start with the zero and start with the standard polar stem. And what that's gonna do just gonna kind of set this at a general spot, 40 15 with 15 degrees of stem and aversion. That's gonna show you a plot, an implant impingement plot as well as activity uh circle and from there, um you can actually gain a lot of information. Um uh The first thing we want to do is we're gonna want to set this to functional plane on the functional plane. Next step usually is just if we look at our activities of daily living and our impingement zones, we want to try to um get that as best possible. So you're gonna hit the auto center button which is gonna try to minimize our impingement zones through all activities of rain or activities of daily life living. Um And then that's gonna, so you can see that that sets your cup inclination and aversion um based on uh best, best modeling here. If you wanted to compare, we could go in um and put something different and we'll see down in the screen down here. Um And let's just go uh uh with a, a bigger head. Actually, let's do this just for the sake of, um, just to see the differences and you can see now we have, uh, two different models. Set blue is gonna be the blue ring, pink is gonna be the pink ring. Um, and you can see those two different zones on the activities. You can see it. If we click on one of the activities, it's gonna break that down for us. You're gonna see the motion over in this panel over here. You're gonna see the motion of the femur, um, up in this, uh, box up here and down in the implant impingement, you're gonna see that motion represented here. Um And you can see how close, uh, this person comes with a stiff spine or a few spines, sorry, how close they come to implant impingement. Um And if we really wanted to make this, so we can see things, uh, let's just take our liner and add in a lip liner. Um, and you can see, uh, in this version of this, um, I don't know if we click this and go back. Um, this model is gonna show you, um, and the activities if it's red that in those red portions you're getting implant to implant impingement. And so if you see that you're gonna want to change, obviously, something about your, um, implants at that point in time to try to minimize that. Um, you can change your implants. You could also, if you needed to start to change the cup inclination and aversion um slightly to see if you can change that. Um So if we just go back to kind of, let's just go back to our original plan. Now, which is this, um, we've auto centered it, which gives us the best um um version of where our cup should be um based on this person's fused spine. Um And then from there, um, if we're talking about hip navigation, once we've set our functional plane where our cup needs to be, we're happy with our activities of daily living, no impingement. Uh The next thing you're gonna do is you're gonna switch this to the anatom pelvic plane, um slightly different referencing zone. But now this is what we're gonna take from this, the hip modeler into our hip navigation and those numbers are gonna be your goal when you're navigating your cup um with the navigation system. So once you're happy on this screen, we'll just come up here, we're going to go to the next screen which gives you a summary page of everything that we've just done. Um up in the top corner up here, it's gonna tell you what you've what your implants are. Um R three with a neutral liner, 28 head, zero neck. Um It shows us that we're referenced to our anterior pelvic plane. It shows us uh what our stem version is and the inclination and a version of our cup. Uh goal of our cup position we can see down here um in this box that it gives us some variations in ephemeral an aversion. Um 15 is set as a standard. Um um But if you feel like there's a slight change, you, it gives you different options of where your cup can be placed. If you feel like there's slightly less or slightly more an aversion up in this box up here, it shows you your panels of where you'd set uh your slope and your pelvic referencing. Um It once again shows you your Sarel slope um change uh which defined as a fused uh fused spinal pelvic mobility with zero pelvic tilt for this patient. And then it comes down and shows you this implant um and activities of daily living uh graph once again. Um And this is what will get taken into the R I hip navigation system uh if we upload it to quant. So once you're happy, once again here, we've got all this information, we're gonna upload into quant into our patient's data. We've succeeded in saving it. And from there, um that is uh the end of the modeler. And we can go find that once we get into R I hip navigation inter operatively and pull this screen up to, to reference when we're navigating um our total hip arthroplasty. So, templating is a two D version of a of a patient's pelvis where we're generally just placing implants over um their radiograph. Uh hip model allows us to take some of that information along with information from standing and sitting radiographs that then allows us to take into account a patient's spinal pelvic mobility and then more accurately place an acid tabler component based on what their mobility is. So the R I hip workflow starts with uh digital templating, preoperatively. So that starts with radiographs you get in clinic uh from there, you're gonna template uh your case for surgery. Part of that is gonna include using the king mark to be able to identify points that we're gonna utilize in R IP navigation at the end of this process to be able to plan for your cup placement. Uh Once you do that, that I think that's where hi Modeler comes in. And then you take some of that information from the sitting and standing lateral radiographs, which then allows you to account for their functional plane and plan for a tablet component placement and position based on their functional plane. And then you use that information uh and bring it into our hip navigation inter operatively to accurately place your acetabular component based on the information you received from the hip modeler. So I use modeler in my daily clinical practice obviously to plan for operative cases, but I think it can be utilized also in uh informing patients uh preoperatively uh based on their spinal pelvic mobility of possibly um positions. They may need to avoid, you can talk to them and go over the activities of daily living functions um and show them actually what happens when they do these activities to try to inform them a little bit better about uh things that they may want to avoid or try to uh keep a look out for, I think tips and tricks uh for learning curves. Um uh I think importantly, early on uh may not need to deal with hip modeler but getting good radiographs um that you can use. That's probably one of the big tips and you really have to work with your radiology department to make sure you're getting accurate films that then you can, then you can base your templating off of. Uh and then I think it takes some time really to be able to identify the landmarks that you're looking for the S one N plant and your A SI S and your synthesis uh because it does take a little bit uh looking at radiographs to really identify those things um and put your points accurately. And then also I think tips and tricks um early on in the process is using the modeler uh and comparing different stems, different cup, different liners to be able to see what those changes um do to their activities of daily living and see where you possibly might get imp implant on implant, impingement uh based on the different um different implants that you choose. And you can kind of see what happens based on those implants and make some informed decisions about maybe changing implants that use if you need to.