3D printing cranial and craniofacial implants

[Dr. Mike]

I receive a lot of inquiries to my account. I'm going to try to share them with the community in the hope that any information that is shared can help many others. A member recently contacted me and asked the following:

 

"I am a Biomaterials and Tissue Engineer by profession and recently got into 3d printing of medical implants. I would be greatly obliged if you could please advice me on designing 'cranial mesh' My task is to design titanium based cranial mesh. I would like to know if you can suggest me any tutorial on the same." 

 

Another member asks, "

I am a resident in neurosurgery in Brazil and I have a dream to allow cheap cranioplasty for those in need that depend on Brazilian public health system. If you have some sort of tutorial using free software to make those prosthetic cranial grafts of a cheap way to make a mold out of it I will be glad to hear from you. I am planning on buying the ultimaker 2 printer which allows direct PEEK print and also PLA print for mold to go through autoclave."

 

I must admit that I have limited experience with craniofacial implants. I know that the physicians at Walter Reed Army Medical Center in Bethesda Maryland are doing pioneering work in the field. Regarding making titanium-based implants I am unaware of any tutorials, but a search on Pubmed has yielded a few helpful articles. Here is one https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4073471/ From what I have seen most of these implants are designed using the Mimics system by Materialise.

 

Regarding the low-cost solution for cranial implants, I'm not familiar with any freeware software that specifically does implants. From the hardware perspective, you may want to consider a Form 2 stereolithographic printer in addition to the Ultimaker 2 (FYI, there is a new Ultimaker 3 printer out). Formlabs, the makers of the Form 2 have a tutorial on using their printer to make molds for casting. https://formlabs.com/blog/3d-printing-for-injection-molding/  Formlabs has a dental biocompatible resin that I know some hospitals (Mayo Clinic) are using for in-surgery cutting guides. I heard them talk about that at a conference I recently attended. Whatever you do, make sure you follow the health safety rules in your country and take all necessary steps for patient safety.

[Saumyam]

Hi Dr Mike Thanks for this blog post.

 

I came across this one method of designing cranial implants (attached link tutorial video) using the free software MeVisLab....I have yet to try it myself as I was not able to understand the whole method/workflow

https://www.youtube.com/watch?v=8epxE8pUMPk

 

Apart from that there is another software , Geomagic Freeform  but that too is paid one...

[kopachini]

I was also interested into making craniofacial implants, and also i have found MeVisLab free software, but i found it very complex to work with.

Than also i tried with Geomagic Sculpt and Freeform, but as Saumyam mentioned they are pretty expencive (retailer in my country said that the price is aroud 2000€ for Sculpt, and 6000 € for Freeform, and 8000 € for Freeform Plus).

It was very hard to work with Geomagic sculpt (laggs, unresponsice control etc.), but Freeform was discovery and I am very pleased with that software.

Here is model of custom made cranial implant that I made using Geomagic Freeform trial version and Blender. Few details remain to be done on it.

[Saumyam]

Hi Kopachini , this looks great ...except the 'holes' look non-uniform... how did you manage to use freeform plus ? I could not download it .... also do you have any tutorial/referral on the same... 

 

Thanks 

[kopachini]

I used trial version.

I  was in a bit hurry and very nervous when i made this model so thats's the reason why are holes non uniform.  

[Saumyam]

not an issue with the holes , have you gone through any paper / tutorial for geomagic freeform or you did it by yourself? either way it looks fine...thanks for posting

[kopachini]

There are tutorials you can combine from there maybe  http://support1.geomagic.com/Support/5605/5668/en-US/Article/View/2368/Geomagic-Freeform-Tutorials

[Saumyam]

Thanks for posting this link, will try them.

 

I came across this article relevant to this post

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4615389/

 

 

[Egiiiii]

Hello,

 

I am a industrial design engineer from Hungary. I work in a Clinic near the Austrian boarder. I design and manifacture CAD/CAM bone grafts from human allograft for doctors and patients. I work whith many cad software and CT software. I was also intrested making other implants for humans, and I would like to share a plan with you. I'm curious about your opinion.

The first picture is a human allograft, what I design and manifactured. These plans are alredy implanted.
The second picture is the plan, what I designed.

[kopachini]

Regarding to your second pic and implant for the orbital floor, I spoke to one of the maxilofacial surgeons in my hospital and the main problem would be precission... orbital floor implant anatomy should not differentiate than original patients anatomy more than 2 mm or you get diplopia.

[Egiiiii]

Thank you your regards. The precission is always the main problem:) I think it is even more precise than the surgeons carve a new face implant from the patient tibia bone (last week I met a man, who wait his operation, and he get a bone implant from his tibia). So when someone draw a accurate implant, and make surgery guide too, It can be very precise. But I am not a doctor

[kopachini]

On 16. 05. 2017. at 9:44 PM, Egiiiii said:

Thank you your regards. The precission is always the main problem:) I think it is even more precise than the surgeons carve a new face implant from the patient tibia bone (last week I met a man, who wait his operation, and he get a bone implant from his tibia). So when someone draw a accurate implant, and make surgery guide too, It can be very precise. But I am not a doctor

 

Ofcourse custom made models are more precise than bone autografts... But surgeons can use serial made titan mesh and carve it according their needs. Metal printed models are waaay too precise than PMMA made implants too (one team in my country pushes that idea, but I am more into metal implants than PMMA)

[Piotr Zielinski]

I am a neurosurgeon. The simplest way to solve most of our problems in a low cost and rather according to the rules way is to first to print the patients skull (easy). Than to form manually, slowly and exactly a lacking bone from the cheap, available everywhere in the world dental molds (I have succeeded with silicone prosthetic mold). When the bone substitute is ready and firm, then make an impress in a stomatologic  acrylic mass (methacrylate, the ubiquitous surgical material), also available everywhere. Its the same component that we use to form a bone in the operating theatre, but not sterile. If you have the mold ready, you can sterilise it in a plasma autoclave, put in a sterile foil bag in the operating theatre and then form in this foil and form a lacking skull piece from a classic methacrylate. Sterile, with all of the certificates needed. It does work.

Ready 3D printed skull flaps are often imperfect. I.e. they do not take into consideration brain swelling, soft tissue remodelling etc. The mold and forming the bone flap during surgery from PMMA seems to be much more versatile. And you do not have to throw away the bone substitute of 2000 USD into trash.

Best regards,

Piotr

[Piotr Zielinski]

[Piotr Zielinski]

embodi3d has helped me a lot in helping my patients, with no cost. Chapeau bas! If any questions, please contact me. I am a practician.

[Dr. Mike]

Piotr, that is brilliant. Thanks for sharing. Are you doing along of 3D Printing-assited bone flaps?

 

[Josip Rauker]

I am a biomedical engineer, I own a CAD/3D print Company in Croatia. My Company is specialized in production of 3D printed moulds for making patient specific cranial implants out of PMMA. This is a rather cost effective way to produce patient specific cranial impants. I use Solidworks for designing implants and moulds. This software isn´t free, but it's cheaper than Geomagic.

The whole procedure is described in an article I have published on my LinkedIn page:

https://www.linkedin.com/pulse/pmma-cranial-impants-more-cost-effective-solution-josip-rauker/

[Dr. Mike]

Thanks for sharing the link Josip. Nice work!

[valchanov]

My colleagues from Sofia, Bulgaria are using PEEK cranio-facial implants and they have very good result with them. The PEEK is better in every aspect than the titanium, but it is really hard for printing and postrprocessing and requires a specialized 3d printer with extrusion temperature ~400 degrees celsius. Recently my colleagues of Plovdiv, Bulgaria used a PEEK calvaria and according to them, the cost of the implant was 10000$. For me this is too much and I'll beat this price in a matter of 6 months with my team and out newly purchased PEEK-capable printer.

[kopachini]

9 hours ago, valchanov said:

 For me this is too much and I'll beat this price in a matter of 6 months with my team and out newly purchased PEEK-capable printer.

 

And where did your colleagues buy PEEK and for what price if you know? The problem is that medical grade PEEK is still a bit pricey, but not as much as titanium, right?

I saw one company on the internet from the states called Vision Miner which print PEEK and contact them for more info about complications etc. ... they have been printing some implants for hospital in Columbia and all that they could tell me that there were no complications but gave me contact of that hospital so I can ask those surgeons more details , but as today I still didn't.

[valchanov]

I contacted the manufacturer of their implants for some details. It's weird, but they are using this brand of filament, which meets the regulations for food safety (European regulations EC No. 1935/2004, EC No. 2023/2006 and EC No. 10/2011 concerning plastic materials and articles coming into contact with food and is also compliant with the FDA (Food and Drug Administration) for food contact), but not those for temporary/permanent implants. So, I contacted Apium for their PEEK filament, which have very good toxicology/cytotoxicity/mutagenic profile and meets all the regulations, including those for temporary/permanent implants. The prices are good, they have good filament dryers (you have to preheat the PEEK to 150 degrees before it reaches the hotend) and they have a specialized 3D printing system for PEEK (which doesn't concern me, because we already have a PEEK capable 3d printer). In the next half a year we'll perform some tests and if the results are ok, we'll make a phalanx bone for a patient, which is on hold right now. If everything is fine, we'll become a manufacturer for such implants. If not, we'll use Nylon 680. My colleagues from Sofia implanted 3d printed rib from Nylon 680 on a patient and the results are very promising.