co-author: William Brent Wright
0. An Overview of 3D Printing in O&P and What to Consider Before Deciding Whether to Jump In
Before we jump into the how-to of getting your clinic up and running with a printer, we should include an (very) abbreviated background on 3D printing in O&P and whether it is the right fit for you and your clinic.
Academic Research
Despite some of the recent media coverage that might make you think otherwise, 3D printing has been around Orthotics and Prosthetics for a long time — at least 25 years. Rogers et al at UTSA and UT-Austin wrote about using Selective Laser Sintering (SLS) to manufacture sockets in 1991. At that time, teams like Walsh et al (some of the same folks) were already writing
about the potential impact of a digital toolchain to go from scanning to manufacturing without ever touching plaster, and how that would increase access to care around the world. Yet, progress was slow. 10 years later, articles were still popping up titled “A preliminary investigation into the development of 3-D printing of prosthetic sockets”.
I would argue this wasn’t actually a preliminary investigation and that quite a bit of evaluation had already been done, but nonetheless, the only notable commercial progress in the early 2000s was Northwestern’s development of the “Squirtshape”, a printer design that has yet to grow to widespread use.
Commercial growth of the digital workflow in O&P
Despite 3D printing not seeing many patient rooms, the availability of 3D scanning and CAD design did increase in popularity. Companies like Vorum, Biosculptor, Omega, and Hanger’s Insignia demonstrated that digital workflows had value as a tool for O&P clinicians to explore. Yet, the price of scanners and carvers and the difficulty to learn and master the digital procedures — among other things — stemmed the excitement and left quite a few unused carvers and expired software licenses. On our visits to clinics around the world we’ve unfortunately heard the same story too many times — “ I was totally sold on the idea. And I dumped a quarter of a million dollars into this system. But I could never pick it up. And I wanted to try it again, but nothing has changed in the last 10 years. It’s been sitting in the corner for a while and no one knows how to use it anymore.”
What we learned is that the value proposition wasn’t wrong. Scanning + CAD + CAM can save clinics a lot of time! But, the solutions weren’t yet right for everyone to really adopt it.
The 3D printing revolution
In the past decade or so (maybe a bit longer, depending on your perspective), 3D printing has become decidedly more accessible. Patents on Fused Deposition Modeling (FDM) printers expired and companies like MakerBot started “the 3D printing revolution” by advertising a much more affordable and easy to use, albeit much less fully-featured, desktop 3D printer, even garnering a Netflix documentary in the process. Granted, larger companies like 3D Systems and Stratasys had been around for a while, but their goal was never accessibility to printing in the same way that MakerBot’s was. They were trying to empower centralized manufacturing. MakerBot was trying to empower distributed, at-home printing.
With printer prices dropping, development of associated software increased as well. We’ve seen softwares like Meshmixer, TinkerCAD, Blender, Fusion360 and so many more grow in popularity over the last 5+ years as generalized 3D modeling tools. The software is often difficult to learn (even for engineers with 3D design experience), but this combination — low-cost printers and software — have made 3D printing accessible to nearly everyone. And even if you didn’t want to learn the software or the printing, you can download a file off of Thingiverse and have it printed by your neighbor on 3dHubs.
Technology application in your clinic
Yet, this still hasn’t led to a transformation of O&P. What gives? A few things, probably:
3D Scanners have only recently become affordable and widely accepted as accurate enough (Specifically, the Structure Scanner from Occipital has become well-known and widely adopted). If you’re already bought in that the Structure Scanner is great, feel free to move on. If not, a few points to consider:
- At this point, there are only a manufacturer or two that won’t accept scans from the Structure Scanner as accurate enough for them to include their warranty on fabrication (and this may not last much longer). As an aside, this trepidation grew because the resolution and accuracy of the scan varies based on the scanning app that you use. Some early (and even current) versions of scanning apps require hand measurements to be taken so that the scans could be scaled correctly. There are a few solid ones that exist now: TechMed3D’s 3DSizeMe, LifeNabled’s Digiscan3D, and our Design Studio Scanner.
- Many legacy vendors of O&P CAD/CAM make their money selling 3D Scanners and 3D Carvers and have continued to disseminate misinformation about the accuracy (or claimed lack there-of) of the Structure Scanner. While there are some specific use-cases where other scanners are more appropriate (namely, helmets for tracking and FDA regulatory reasons), the Structure Scanner has proven time and again to be an equal or superior option to its expensive counterparts.
Software is still hard to use! The historical options for software in O&P are expensive, difficult to master, and mostly incompatible with modern technology. Until recently, you were forced to use specific manufacturing methods or machines and could only download your files in proprietary, non-shareable formats. The training is expensive and support is difficult to come by.
As an aside: I’d be remiss to say — this is one of the problems that our system aims to fix. Easy to use, you own your files, new features being added often (driven by your user feedback) without any update fees, compatible with any and all manufacturing methods, and accessible and available support.
Fabrication is the piece that is a bit tougher to unpack. To some extent, outsourced, centralized manufacturing at central fabricators (C-Fabs) has become widespread in the US, with shelves and shelves full of molds filling warehouses like SpinalTech’s and Ottobock’s.
Carving, with its high up-front capital cost, but ability to churn out high volumes of positive molds, fits great at the Central Fabricator (or large-volume clinic) level. There are now well over a dozen high-quality, well-regarded Central Fabricators that predominantly carve models for clinics in their region or around the country at relatively affordable prices. The quality and finish of the devices received at the clinic are comparable (if not superior) to the quality that would have been produced in-house. A non-exhaustive list would include Ossur, FabTech, Friddles, AOPS, Ottobock, SPS, SpinalTech, Orthomerica.
In the case of these Central Fabricators, clinics have been able to outsource fabrication of digital models, enabling them to get up to speed on the scanning and software without the hassle, cost, or overhead of doing fabrication in house.
While we started doing fabrication of digitally designed test sockets for our software customers, we quickly realized it was a skill best left to that list of experts. We transitioned our software to be digitally integrated with many of those vendors, allowing our users to design and order devices without ever leaving our app.
While there has been a proliferation of Centralized Fabricators in the last decade, the last few years have seen a large number of new entrants using 3D printing as a differentiator. Early on, we identified TriFusion Devices and their patented FlashFuse Technology as a unique and necessary addition to the printing landscape. Other pioneering vendors like Additive O&P and Protosthetics have offered their services in recent years as well and pushed the market to see 3D printing as a viable fabrication technology. Yet, with understandable excitement and eagerness, some vendors and practitioners marketed 3D-printed definitive sockets early on despite limited mechanical testing. Efforts like that, in addition to the broad media coverage of printed devices like the e-nable hand, have unfortunately led to mixed feelings in the industry and some understandable hesitations. Which brings us to one of the largest points of contention regarding 3D printed sockets (and 3D printing in O&P in general): how strong are they?
The easy answer: it depends.
Laminated sockets have decades of use to reassure us of strength and safety, and because of the difficulty to create standards for mechanical testing of sockets, there are no publicly available test methods to replicate (although some of those C-Fabs above assuredly have internal standards they test to). We’ve always cautioned “be wary” to all of our software customers when it has come to promises of 3D printed definitives. But, in recent months, TriFusion Devices and Extremiti3D have each announced completion or near-completion of rigorous 3rd-party mechanical testing to demonstrate that their sockets are multiples stronger than the knees and feet in the prosthetic system. That said, this is far different than saying that your at-home printer with broadly available filament is consistently capable of making definitive-quality devices. It might be, but maybe not.
All of this to say: 3D printing, like lamination or thermoforming, is a science, and perhaps even moreso. The variables that go into getting the socket or orthotic printed perfectly and consistently are vast and finicky. We almost always recommend that these variables be controlled and tested in a structured manufacturing environment where quality systems are instituted and trained and experienced machine technicians work full-time monitoring production and verifying everything is working as expected.
Our thoughts
And this leads us (finally) to our recommendation, developed over the last 3–4 years visiting innumerable clinics and fabricators:
In nearly every case (there are always exceptions), we recommend that clinics use scanning and digital modification for almost every patient — orthotic or prosthetic. We likewise suggest that they outsource their fabrication to a central fabricator that is able to capture the efficiencies and quality benefits of manufacturing at scale. There are cost savings in labor, space, and materials associated with outsourced fabrication that can be sizable!
Given that we’ve got well over 5 chapters worth of content to follow, this recommendation may be a bit confusing. But we will always respect your clinical judgement and give you as a clinician the tools to make the decisions you feel like are best for your patients. So, if you’re going to get a 3D printer for your clinic, there are some things you need to know that we’ll lay out in the sections to follow.
Side note: There are two main ways you can do digital manufacturing in-house. Carving, like we’ve mentioned above, is a viable option for very fast creation of positive models. But the up-front capital costs make it cost-prohibitive for almost all clinics, so we’re focusing our content on 3D printing, the second option for digital manufacturing.
So, if you do decide to manufacture devices in-house using 3D printing, we suggest that you stick to test sockets. This is where you’ll get the most benefit from next-day turnaround time (although even this is often available from a local c-fab) and where you can rest easiest knowing that any manufacturing inconsistencies will be wrapped with fiberglass and won’t be leaving your office. Definitives may be print-able by the expert 3D printers of the community, but we’ll always suggest that even they implement a quality system with rigorous standards. The FDA finalized their guidance with recommendations on 3D Printing in December 2017 which include sections on materials controls, process validation, and device testing — scope that may be outside the expertise of traditional clinics to implement.
FAQ — a few common questions before we get started
- Do you have to be an engineer to learn how to use a printer? It looks so hard!
There are groups & vendors — within and outside of O&P — that are taking advantage of the intimidating nature of learning something new like 3D printing and are reselling printers for more than 3 times the cost of their original value under the guise of including training on how to learn and use the machines and associated software. Don’t take the bait! One of the beauties of 3D printing is the online community that shares openly and helps each other solve problems. In addition, printers and software have come such a long way that you may not need as much help as you might think (hopefully this guide can get you most of the way there!).
That said, there definitely is value in finding someone who has been there before to walk you through the hard parts. If you’ve walked through this guide and still feel like you want that reassurance and support, there are people that can help! Within O&P, there are classes at Steampunk Bionics or vendors like Create O&P and TriFusion Devices that offer printer setup and support services for a fee. Another great option: Brent Wright, the co-writer and editor of this content offers consulting services from a practitioner (and 3D printing expert) perspective and is an incredible resource. - Do I need an “O&P-specific” printer?
When vendors are marketing printers specifically for Orthotics and Prosthetics, what they typically mean is that it has the ability to print large objects. Some may be tuned for printing large objects quickly (large nozzles, etc), and may even be pre-built and calibrated for beginners (including things like automatic bed leveling), but for the most part, printing an AK socket won’t require different hardware than what’s useful for printing any other type of large object.The use-case-specific printers (i.e. “made for O&P”), are typically printers that have been slightly modified and are resold with new branding. The printers we’ve suggested in “III. What Printer Should I Buy?” are all off-the-shelf printers that don’t require any modifications to print prosthetic sockets well. - Am I the only practitioner doing this?
There were well over 100 people at the all-day AOPA session on 3D printing in Las Vegas last fall and interest is only growing! We’ve even seen a half-dozen universities including 3D Design and 3D Printing in their curriculum — skills your future residents will come equipped with! - How much does it cost to learn how to get started with a printer?
This guide is most definitely an amalgamation of better content that can be found online, but hopefully distilled in a format that is useful for an O&P clinician. There are innumerable free resources online to help you get up and running with your printer that we’ll include in “VI. References, Acknowledgements, and Resources”. Please share your own if we don’t include them in the resources section!
