3D printing technology was originally touted to provide consumers the ability to print customized mugs, plates, and other household items. The reality turned out to be a lot more exciting, at least for us in the medical space, since 3D printing is already being used daily by thousands of doctors to help perform procedures that would otherwise be too risky or simply impossible. For a great example, you can read our recent piece on how cardiologists at the Henry Ford Hospital in Detroit are able to implant transcatheter mitral valves.
While on that visit, we learned that Materialise, a Belgian company with North American headquarters and a manufacturing facility in Plymouth, Michigan, is responsible for a lot of the technology that allows Henry Ford’s clinicians to implant the valves. We wanted to learn more about what Materialise is up to and so took an opportunity to visit their local offices to take a first-hand look.
Located outside of Detroit, one may be surprised to learn that Materialise’s local operation doesn’t work with the auto industry, instead focusing specifically on medical 3D printing. And print they do: tens of thousands of surgical guides, anatomical models, and planning tools are made on dozens of printers every year and the pace is only increasing as more clinicians adopt the technology in their practice. The printers are utilized round the clock, save for cool-down times, regular maintenance, and such, and most print jobs result in multiple parts being produced together. In total, they printed more than 2 million unique parts last year!
An orthopedic surgeon requiring a precise custom cutting guide to position an implant, for example, has to follow a few steps and consult with Materialise to get the perfect part for a given surgery in the mail in just a few days. The workflow starts with obtaining a CT scan of a patient using a protocol that works well with Materialise’s software. The scan, which is really a bunch of 2D DICOM slices, is converted (segmented) into a 3D planning file which can then be used to design a cutting guide.
At this point, a specialist from Materialise will typically converse with the physician using online screen sharing, discussing the requirements and capabilities of the part and answering each other’s questions. (Knee guides usually don’t require this, as the surgeon can input values on his/her own since knees procedures have become very standardized.) Once everything is agreed on, the part is finalized on the computer and sent to the printer, cleaned up, and shipped out. If the surgeon submits the go-ahead before 10 am, the part will be sent out by 4 pm the next day. The part is received, unpacked, sterilized and can then be used with full confidence it will match the anatomy. Of note, each part has patient information right on it, so that mistakes don’t happen during a procedure.
Custom cutting guides are not new, but previously they would be up to 15 degrees off of the perfect match, while now the number is about 3 to 4 degrees. One big reason custom guides exist is because the implants themselves can’t be custom made for each individual patient without them costing significantly more than they do now. As Bryan Crutchfield, vice president and general manager of Materialise North America describes it, the process is”customizing the patient to the implant rather than implant to patient.” This is why planning and precise manufacturing of the guides is so important.
While 3D printing has been used in medicine for a few years now, only recently has the FDA provided guidance and started requiring regulatory clearance of the workflow used to 3D print medical tools that are used in diagnostics and for pre-planning of surgeries. Only a few months ago, Materialise became the first company to receive FDA clearance for software to 3D print patient specific anatomical models.
Currently the firm only makes plastic parts in the U.S., but it has recently submitted a titanium hip and shoulder to the FDA to obtain clearance, devices that are already made in Europe thanks to a less stringent regulatory process. Some titanium parts, such including implants and guides, are already available to U.S. surgeons, but these are made at the company’s Belgian facility.
Cutting guides are the parts most ordered from Materialise, but they also make custom shoe orthotics that are becoming popular among pro athletes, dental splints for cutting the mandible or maxilla loose, tooth impressions to help align the jaw (Materialise’s own idea, distributed by Depuy Synthes), large cranial plates, custom eyeglasses (partnership with Hoya), cardiovascular models, and other medical and surgical tools. They even make models for other manufacturers to help custom machine parts that cannot be easily printed.
Most of the custom tracheal splints that make it to the mainstream media, and many face reconstructions, hand transplants, and other highly unusual procedures rely on parts made by Materialise. The tracheal splints, which are made of a material that dissolves in the body as tissue grows around it, are about to go on a clinical trial at the University of Michigan. About 2,000 cases a year could be done like this in the U.S. once everything proves out.
The printing process for parts to be used during surgeries requires virgin plastic powder that hasn’t been recovered from other processes. The company has a few types of machines, but most of the surgical parts are made using a nylon 12 plastic powder that is deposited in layers 1/10 of a millimeter in depth and that is melted into a solid using a laser. Once a layer is done, a new layer of powder is applied and the laser melts in another layer. The chamber where this occurs is close to the melting point of the material itself, so it requires cool-downs before the produced pieces can be extracted and a new batch restarted.
There are also stereolithography machines, which look very futuristic, but that actually represent the first type of 3D printing technology that was developed. Here a vat of transparent, UV reactive resin is illuminated with UV lasers, solidifying the resin where the laser generates the most heat. The resin moves down 1/10 of a millimeter each iteration of the printing cycle until the solid piece is whole and can be separated from the liquid resin. As the process happens, one sees light beams shooting through the resin and the device slowly appearing in front of one’s eyes.
We saw all kinds of implants, guides, models, and other medical devices on our tour of Materialise. Each piece was unique and manufactured for a specific patient, something that was nearly impossible in most cases just a few years ago, and something that many people would be surprised to find out is already routine for Materialise.
Here’s a Materialise video showing off the company’s medical services and achievements:
Link: Materialise Medical…