00:00My name is Philip Bernborg, I work as a biomedical engineer here at the University Hospital in
00:09Skåne. Together with Einar we're going to present in-house manufactured p-cranioplasty implants
00:16and our initial experience from the hospital.
00:23Right, I needed to do just a request, so thank you.
00:27So, background. As far as we know we were the first to implant a completely point of care produced peak
00:34implant last year and since then we have also produced two more implants which are implanted
00:42to more patients. So in total three patients so far and we have a study for 40 patients that is
00:49currently ongoing. So in the agenda today we will talk a little bit about who we are,
00:59we are going to explain what cranioplasty is for those who don't already know, a bit about the
01:05regulatory aspects that we have been facing when we are we have gone into this project,
01:11a little bit about the workflow and how we design our implants, and then a short conclusion, and then
01:17Einar is going to do a live demonstration of implant design process that we are using.
01:25So about us, we started in about 2018. We are still a very small team but currently we have 12 printers
01:33and we are four employees. So cranioplasty, cranioplasty is the surgical repair of a bone defect in the skull
01:44resulting from a previous operation or injury. So in the initial stages, we were contacted by the
01:58neurosurgeons who wanted us to help them create implants for them. At the time they were making
02:05implants by hand by using polymethyl methacrylate but by doing this by hand it was kind of pretty
02:13time consuming and it was also pretty difficult for them to create an implant that would look aesthetically
02:20good for the patient but also be easy to fit in the patient's defect. But at the time they wanted
02:29us to 3D print them but there were no available implants for medical implants at the time so we
02:36needed to go another route so we went for creating molds instead. So we created two-sided molds
02:44and we have been using them to implant about 40 patients so far.
02:58So why peak implants? Well they allow us to do more complex designs than the molds would allow us to do.
03:06You could add more features that are easier to make and you could also create geometry
03:14which are very difficult to create using molds. And more importantly they are more time-saving because
03:22in the operating room if you need to create the molds or use the molds to create the implants
03:30and the time saving is about 30 minutes and that's a lot of time in the operating room.
03:36And in the literature we have also seen that there is fewer complications when using the beak implants
03:41compared to bone cement which is polymethyl methacrylate. And why would we want to do this at point of care?
03:49Well the point of care allows us to do faster turnaround from referral to surgery. This makes it
03:55in theory possible for us to create an implant from patients in less than 24 hours. It also allows us to
04:03do rapid design iterations since we have a very close cooperation with the surgeons.
04:09And we also, a huge benefit is also that we don't need to send our patient-sensitive data
04:17outside of the hospital and we can keep everything inside of the hospital's firewalls.
04:25So the most difficult part of the project was finding out the regulatory aspects of the project. We needed to
04:32make sure that our implants are as safe as possible but still being able to do them at the hospital.
04:40What we needed to do was find a printer that could produce
04:44implant-graded materials, implants. And we also needed to find a filament that could be used for peak implants.
04:53So we found the APM printer which is able to produce the implants and keep both the
05:01implants and the filament clean during the process. But we also needed to check that this was also the
05:08case. So we did some mechanical tests to see that our implants were sturdy enough and we needed to do
05:17some dimensional accuracy tests to see that our implants look the same from our design to when they
05:24were finished in the printer. And we did some print tests and post-processing tests to see that which
05:30geometries and orientations were the most beneficial for us when we were printing. And finally we also
05:37needed to do a purity test to find out that chemically we did not introduce any byproducts into our prints.
05:51So the workflow as we probably most understand is that we would need to do some CT imaging to get
05:57patient images. And from the images we would create an implant and then we would send this computer
06:06regenerated design to the surgeon where they can look at it. And in some cases we also send some
06:13some prints that are not medical graded filament of course so that the surgeon can look at it.
06:19And if they approve of it we will print it and then we will send it and we will also post-process it
06:25to remove supports and also sand the implants as little as possible so that we don't remove too much
06:32material. And then it can be sent off to the sterilization department so that it can be sterilized
06:38and then be sent to the operating room. So the parts that are delivered to the surgeon is the
06:45sterilized implant of course. We also supply them with an implant guide which is sort of a dummy implant
06:52that the surgeon can use to see that the implant is actually going to fit inside the defect. And that
06:58is a way that we want to make sure that the implant is actually going to fit inside. And if it doesn't
07:06fit then the surgeon can easily remove some more bone and then use the and then they can be sure that
07:12the implant is going to fit. We can also supply a cutting guide but that is an optional thing. That is
07:20in the case in the cases where the patient has not already received a defect then the surgeon
07:28wants to create a defect instead if they want to remove some damaged bone or something else.
07:35We also supply them with a backup mold in case something would happen with the sterilized implant
07:41if someone were to drop it and it wouldn't survive that or something else.
07:48And then finally we're supplying them with a patient-specific document and that is the
07:54information about the patient and also some good to know information about the implants.
08:02So summary, it's feasible for hospitals to produce their own patient-specific implants as we have shown
08:09but there are a few regulatory challenges because of the MDR. But there is a good potential for hospitals
08:21to do this by themselves and so far we have implanted three out of 40 patients.
08:28And now I'm going to hand over to Einar who is going to show you how we design our implants.
08:34So thank you. So at the Skåne University Hospital we have a really close collaboration with Medviso.
08:41I'm in fact the founder of the company and also still an active developer of the software.
08:47So I will show a live demonstration here now on how to do an implant design so we can see. In the
08:54previous talk we heard about 10 minutes so I will try to do a complete implant design on how we do this
09:01at the hospital in less than 10 minutes.
09:05So here we have the, do you see my screen?
09:10Yeah.
09:10Yes.
09:11Good. All right. So what I can do is first is open the patient database.
09:19So I load this and this is the same, this is the peak case, the first implant that we did at the hospital
09:26to show it on the real data. So here we can directly see an overview of the CT images and CT scan.
09:37I can then do a skull segmentation, automatic segmentation.
09:43So then we can visualize it in 3D so we can see how the defect looks. So it looks something like this.
09:55It can make a small smoothing of it.
09:58Okay. And now we're ready to generate an implant design, skull reconstruction here.
10:11We need to supply the computer that the defect is on the right side.
10:14So the process will be that we will mirror the healthy side to the defect side.
10:22The first step is I need to select where the defect is. Something around here.
10:31There. Okay.
10:32Okay. Now, what I will do now is I will adjust so I can make my mirror so it fits with the skull,
10:44something like this.
10:47Then I now automatically generate what will be the outside of the new reconstructed skull shape.
10:56So I go over that and see, do I need to make some minor manual adjustments? And here is one example.
11:04I want to make a small adjustment here.
11:09So I want to create a symmetrical looking skull here.
11:15Adjustment there.
11:18Here.
11:22And then finally here.
11:24So with that, I can sort of see that I reconstructed a good looking skull shape here.
11:32So click done here.
11:37And now we'll create an implant that is with thickness four millimeters and no margins.
11:49So some of the minutes goes to computer calculations.
12:03So here we have a new implant.
12:05And we can see how it fits with the skull.
12:09As you can see, it looks really good.
12:11I can go for a full screen here.
12:14So you see a bit more better.
12:15You can see it from the front.
12:18So you've been able to reconstruct and go from the back and then from the side.
12:26So something like this.
12:27To be a complete printed implant, we need to have holes that we'll attach to the implant with and also
12:39have drainage holes.
12:42So we'll add these two now.
12:43So then we'll do that by having a point tool.
12:49Simply put points along the contour here.
12:53So this is really to show that if you make the software easy enough, it is possible to do this
13:10directly at the point of care that this can be done at the hospitals.
13:15So I create a curve here.
13:20I want to have my screw holes inside.
13:23So I move them in.
13:25I move them in six millimeters.
13:28Okay.
13:32And then you can go for the implant here.
13:35So I want to put some holes where I can attach it.
13:40So maybe here.
13:42And these locations where it's good to put screw holes, this is something that we typically discuss
13:48with the surgeons if there are specific constraints.
13:53That could be especially around the temporal lobes or temporal region in the skull.
13:59Sometimes we don't want to generate something like this.
14:07And I drill these holes.
14:10So those are holes there that I will put my titanium plates on to screw this implant on.
14:27Now this.
14:29And then here I will put some of these what we call drainage holes or so.
14:36So now I'm almost ready the implant.
14:50The last thing I need to do is to put the name on it so it has to be patient specific and labeled as such.
15:04So I will again use my point tool here.
15:11Okay.
15:12And then.
15:14Yes.
15:15Right.
15:15Patients.
15:16So mark this as a patient specific.
15:18So we use the initials and the memory of the year and send the last four digits.
15:23So I will put the name here and then we can engrave it and with this I'm actually finished with my
15:53implant.
15:53So this is the final implant.
15:56And I'm ready to send this to the printer.
16:00And again, we can sort of ask and here with see how it looks.
16:06So this is how it looks together.
16:09The final implant.
16:10So with that, I hope that you got an idea on our initial experience is that this is actually
16:18possible to do in-house at hospital.
16:21It is the tricky parts are the quality management systems you need to do and
16:26to keep track of all regulatory testing and all these regulations.
16:35I can say that this study was formally started on just before MDR kicked in.
16:40So it is running under MDD.
16:44And we are now sort of looking in how we will do this in the future under MDR as well.
16:53So with that, I open for questions.
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